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340 Cards in this Set

  • Front
  • Back
cardiac failure (causes)
-damage to myocardium
-increased resistance to outflow (eg. lungs)
-inability of heart to expand
-valvular defects (endocarditis)
-irregular rhythms
cardiac failure (acute vs. chronic)
Acute: sudden cessation
Chronic (congested heart failure):
-left sided: blood backs into lungs (pulmonary oedema)
-right sided: blood back up in circulation (enlarged liver, ascites, hydrothorax in cats, limb oedema in dogs)
diseases of the pericardium
-hydropericardium: fluid w/in pericardial space
-haemoparicardium
-pericarditis: inflammation
-cardiac compression: adhesions so doesn't move properly (acute & chronic)
-herniation: heart breaks free from pericardium
hydropericardium
-watery, serous fluin pericardial sack
-generalized oedema
-toxaemia
-ost mortem change: sanguinous (blood tinged)
haemopericardium
-ruptured atria (valvular disease or tumor): dogs
-ruptured aorta: horses (and turkeys)
-penetrating object
pericarditis
-inflammation of pericardium
-serous (eg. dog tuberculosis), fibrinous (eg. Glasser's disease) or purulent
-routes of infection:
1. haematogenous (eg. pasteurella, E. coli)
2. mycardium
3. lungs
4. penetrating foreign body: cattle not sheep (eg. from reticulum)
cardiac compression
-acute: cardiac tamponade (hydropericardium prevents ventricular filling)
-chronic: constrictive pericarditis (fibrosis limits stretching), pericardial effusions (fluid around heart)
-other: herniation (constriction band where heart pokes out of pericardium as in RTA; congenitial defect where liver gets trapped in pericardium)
diseases of mycoardium
-hypertrophy: if forced to work xtra hard (rt heart in patent ductus venosum or interstitial pneumonia/cor pulmonale; lft heart in stenosis or valvular defects)
-degenerations: fatty change (starvation, diabetes mellitis), lipofuscinosis (wear & tear pigmen - appears darker)
-necrosis: constricted blood flow
-myocarditis: inflammation
-cardiomyopathy: functional deterioration of myocardium (eg. arrhythmias)
myocarditis
-viral: lymphocytic myocarditis (FMD)
-pyogenic bacteria: suppurative myocarditis
-parasitic: cysticercus ovis (taenia ovis) & c. bovis (taenia saginata)
hydropericardium
-watery, serous fluin pericardial sack
-generalized oedema
-toxaemia
-post mortem change: sanguinous (blood tinged)
cardiomyopathies
1. hypertrophic: wall thickened --> incr. chamber size --> decr. CO (cat, dog, rat, incr. HR in hyperthyroid cats)
2. dilated: lg. heart w/ thin walls weakens --> can't contract well (lg breed dogs, cow, cat w/ taurine defic.)
3. restrictive: unable to contract properly b/c fibrous adhesions (cat)
diseases of endocardium
-valvular endocarditis
-mural endocarditis
-mecrotising endocarditis
-calcification & fibrosis
valvular endocartitis
-bacterial infection of valves (bacteria deposited b/c turbulance)
-friable, yellow & grey masses or vegetations
-layers of fibrin w/ embedded bacterial colonies
-Rt AV valve: cattle
-Lft AV valve: pigs, sheep, dogs
-Aortic valve: horses
-septic embolization to lungs, heart, kidenys (may infarct)
valvular endocardiosis
-degenerative disease of valves in old dogs (esp. king charles spaniels & sm. breeds)
-mucoid degeneration: ground substance ('glue') connecting sheets of edothelum
-smooth, white round thickenings: gap in middle so can't close all the way
-most frequent in mitral valves (regurgitation): decr. CO
valvular disease
-stenosis (valve thickened): failure of valve to open impedes flow
-incompetence: failure of valve to close allows reverse flow (eg. endocardiosis)
-ruptured chordae tendinae: severe incompetence
necrotizing endocarditis
-in acute or chronic renal failure
-yellow-white plaques on wall of lft atrium from urea build up
-incidental b/c renal failure more significant
congenital cardiovascular defects (left to right shunts)
-force right side to work harder
-if higher pressure in Lft: thick right ventricle
-if higher pressure in Rt: thin (only has to pumpt to lungs)
-ventricular septal defects (VSD): always high up
-atrial septal defects (ASD)
-patent ductus arteriosis (PDA)
ventricular septal defect (VSD)
-usually high up under valves
-blood gets from left backt ro right
-oxy mixes with deoxy
-right heart must work harder
-right heart failure
-if VSD persists: right pressure exceeds left & blood reverses again (rare b/c usually treated)
patent ductus arteriosis (PDA)
-connection remains between pulmonary artery & aorta
-pressure higher in aorta than pulmonary artery: left to right flow
-hypertropy of right ventricle (must work harder)
-can be corrected
atrial septal defect (ASD)
-less severe than a VSD (small ASD can survive)
-patent foramen ovale
congenital cardiovascular defects (right to left shunts)
-pressure higher in right side
-Tetralogy of Fallot: must have 4 things wrong (varies depending on which of 4 most severe)
1. VSD
2. pulmonary stenosis narrowing of pulmonary outflow (raises pressure of right ventricle)
3. hyperplasia of right heart due to stenosis
4. aorta sits slighly over right side (displaced)
congenital cardiovascular defects (valvular)
-mitral or tricuspid dysplasia or incompetence
congenital cardiovascular defects (abnormal arterial or venous connections)
-persistent right aortic arch
-porto-caval shunts: persistent ductus venosus, eg.
porto-caval shunts
-congenital abnormalities
-persistent ductus venosus
-abnormal vessels
-hepatic encephalopathy
congenital cardiovascular defects (malposition of heart)
ectopia cordis
pathology of the urinary tract (general course topics)
1. glomerular diseases
2. tubulointerstitial diseases
3. renal pathophysiology
4. lower urinary tract disease
5. clinical pathology (3rd term)
kidney (functions)
-excretion of metabolic wast products: urea, creatinine
-regulation of water content & BP
-regulation of mineral & electrolyte balance
-regulation of acid-base balance
-erythropoiesis
-homeostasis of body fluid compartments
kidney (functional reserve capacity)
-can lose up to 60-75% of liver and recover
-beyond: end-stage renal disease
renal corpuscle
glomerular filtration
-glomerular tuft
-bowman's corpuscle
-bowman's space
-outlet at urinary pole
glomerular filtration rate
GFR = (BP - osmotic pressure) - intrarenal pressure

-BP: affected by CHF & haemorrhagic shock
-osmotic pressure: affected by hypoproteinaemia & dehyration
-intrarenal pressure: affected by hydronephrosis, renal calculi, acute interstitial nephtritis
azotaemia & uraemia
-failure of glomerular filtration: failure of waste excretion, accumulation of toxic metabolites
-urea: relatively non-toxic (used as a biochemical marker)
-cratinine, guanidine, aliphatic amines: toxic, creatinine used as biochemical marker
azotaemia
-elevation of blood biochemical parameters (eg. urea & creatinine)
-prerenal: hypoperfusion
-postrenal: urinary obstruction
uraemia
-uraemic pneumonitis: firm glassy cut surface, pulmonary oedema, mineralization of alveolar walls, degeneration of BVs
-necrosis of oral mucosa: ammonia excretion (ulcerative glossitis & stomatitis)
-haemorrhagic erosion of gastric mucosa: haematemesis & malaena (blood in faeces)
-necrosis of lft atrial endocardium: necrotizing endocarditis, fibrinous pericarditis
-toxic damage to small BVs: incr. permeability (oedema), necrosis, mineralization, thrombosis
-soft tissue mineralization: hyperphosphataemia
-nonregenerative anaemia
-death from heart failure: metabolic acidosis, hyperkalaemia, pulmonary oedema
nephrotic syndrome
-hypoproteinaemia due to excessive loss of protein through glomeruli into urine
-leaky glomerular basement membranes: amyloidosis
-excessive loss of plasma proteins: leakage of albumin, odedema, ascites, anasarca
inflammatory diseases of kidneys
-nephritis: inflammation of kidneys
-glomerulonephritis (glomerulitis): inflammation of glomeruli
-interstitial nephritis: inflamm. of interstitial tissue
-tubulointerstitial nephritis: inflamm. of tubules & interstitium
immune-mediated glomerulonephtitis
-deposition of antigen-antibody complexes (most common in domestics): inectious canine hepatitis (canine adenovirus type 1), canine visceral leishmaniasis, feline leukaemis virus, porcine dermatitis & nephropathy syndrome (PDNS), streptococcus equi, borrelia burgdoreferi
-antibody against glomerular basement membrane (common in humans but not recognized in domestics)
glomerulonephritis (gross pathology)
1. acute: multiple red pinpoint foci in cortex; cortex pale or reddened & slightly swollen
2. chronic: white pin-point poci in cortex; small, pale, firm, irregular kidneys; chronic renal disease
glomerulonephritis in pigs (acute)
-classical swine fever (hog cholera)
-African swine fever
-porcine dermatitis and nephropathy syndrome (PDNS): porcine circovirus
glomerulonephritis (chronic: morphological forms)
determined by size of immune complexes:
1. membranous glomerulonephritis: small complexes
2. membranoproliferative glomerulonephritis: medium
3. proliferative glomerulonephritis: large immune complexes
membranous glomerulonephritis
-most common form in cats
-small soluble antibody-antigen complexes
-generalized involvement of glomeruli
-uniform thickening of basement membrane
-loss of foot processes of podocytes
membranoproliferative glomerulonephritis
-most common form in dogs
-depostion of medium sized immune complexes
-hypercllularity of glomerular tufts & thickening of capillary basement membranes
proliferative glomerulonephritis
-rare in domestics
-deposition of large immune complexes
-hypercellularity of glomerular tufts
glomerulonephritis (consequences)
1. nephrotic syndrome:
-leaky glomerular membranes
-loss of plasma proteins (esp. low molecular weight albumin)
-proteinuria, hypoproteinaemia, oedema
2. uraemia:
-glomerular fibrosis
-reduced glomerular filtration
-inability to excreate urea, creatinine
familial nephropathies
-samoyeds
-english cocker spaniels
-shih tsu
-bull terrier
-doberman pinscher
-finnish landrace sheep
renal amyloidosis
-cattle, dogs, cats, birds, man
-deposition of amyloid in kidney: glomerular capillary BM, glomerular mesangium, tubular BM
-other sites: BVs, liver, pancreas, GIT
-primary (amyloid AL) & secondary (serum amyloid A)forms
renal amyloidosis (gross & histo pathology)
-pale, waxy kidneys with pale, swollen cortices
-multiple pale white pin-point foci: glomeruli
-anasarca: generalized oedema
-amorphous eosinophilic deposits in glomeruli
-birefringent under polarized light (congo red)
-protein casts in renal tubules
renal amyloidosis (consequences)
-leaky glomerular basement membranes: nephrotic syndrome (proteinuria, hypoproteinaemia, oedema)
-occlusion of glomerular capillaries: failure of filtration, uraemia
tubulointerstitial diseases (terminology)
-interstitial nephritis: inflammation of interstitial tissues
-nephrosis: renal tubule (epithelial) degeneration & necrosis (NOTE: don't confuse with nephritis)
nephrosis
-acute renal tubular degeneration & necrosis
-toxic damage to renal tubular epithelial cellls: nephrotoxins, usually substances excreted by kidneys
-renal tubular ischaemia: haemorrhagic shock
nephrosis (continued)
-proximal convoluted epithelial cells: high metabolic rate, 1st cells exposted to toxins
-intact basement membrane: minimal inflamm rxn, epithelial regeneration if mild
-impairment of concentrating ability of tubules: polyuria
-severe nephrosis: death
-swollen, haemorrhagic, oedematous (acute)
nephrotoxins (plants)
1. oak/acorn*: cattle
2. easter lilly: cats
3. red maple: horses
4. lesser loosestrife: sheep
5. oxalate containing plants: docks, sorrel, rhubarb
nephrotoxins (heavy metals & chemicals)
-heavy metals: mercury, lead
-chemicals:
1. paraquat
2. ethylene glycol (anti-freeze): deposition of oxalate crystals in renal tubules
nephrotoxins (antimicrobials & mycotoxins)
antimicrobials:
1. gentamicin
2. sulphonamides
mycotoxins:
1. ochratoxin A
2. citrinin
nephrotoxins (NSAIDS & cancer drugs)
NSAIDS:
1. aspirin
2. phenylbutazone
3. flunixin meglumine
4. ibuprofin
cancer drugs:
1. cisplatin
2. doxorubicin
nephrotoxins (endogenous)
-haemogobinuria: haemolytic anaemia (intravascular haemolysis)
-myoglobinuria: rhapbdomyolysis
-rhabdomyolysis (muscle necrosis): exercise induced (eg. horse rested for few days), post-anaesthetic
-hepatorenal syndrome: eg. bile obstruction (bilirubinaemia)
nephrosis (histo)
1. renal tubule epithelial cells:
-vacuolation & swelling
-necrosis & slough of cells into lumen
-necrotic debris in tubule lumen
2. proximal convoluted epithelium selectively or most severely affected
acute interstitial nephritis (bacteria)
1. leptospirosis: cattle (hardjo, pomona), pigs (pomona), dogs (icterohaemorrhagiae)
2. colisepticaemia ("white-spotted kidney"): calves (E. coli)
acute interstitial nephritis (viruses)
-infectious canine hepatitis (canine adenovirus 1)
-equine arteritis virus
-porcine reproductive & respiratory disease (lelystad virus)
-malignant ctarrhal fever (ovine herpesvirus 2)
-sheep pox virus
*not very common
acute interstitial nephritis (histo)
-interstitial oedema
-infiltration by neutrophils
-neutrophils & necrotic debris in tubules (cellular casts)
-destruction of tubules in severe inflammation: damage to BMs (unlike nephrosis), loss of nephrons (no repair), replacement fibrosis (chronic inflammatory cells)
subacute interstitial nephritis (histo)
-replacement of acute inflammatory infiltrate with lymphocytes, macrophages, plasma cells
-fibroplasia --> fibrosis
-hypertension --> progressive vascular damage
-progressive loss of nephrons: b/c BM damage
-renal failure with uraemia & oliguria (reduced filtration)
-may lose ability to concentrate urine
chronic interstitial nephritis (histo)
-interstitial & periglomerular fibrosis: scarring & distortion
-infiltrates of mononuclear cells: multifocal, locally extensive
-loss of nephrons: reduced renal functional capacity
pyelonephritis
-pyelitis: inflammation of renal pelvis
-interstital nephritis/glomerulonephritis
-acute: locally extensive suppurative inflammation
-chronic: suppurative & non-suppurative pyelonephritis with fibrosis & loss of nephrons
pyelonephritis (sources of infection)
-ascending infection from renal pelvis: up urethra to bladder --> up ureter to renal pelvis
-descending infection from glomerulonephritis
-deposition from BVs at corticomedullary jxn: initiates at interstitum (slowed flow)
-dogs: E. coli, staph spp, strep spp
-cattle: E. coli, arcanobacterium pyogenes, corynebacterium renale
-pigs: actinobaculum suis
renal tubular pigmentation
-lipofuscinosis
-haemosiderosis
-bilirubin: jaundice/icterus
-tubular vacuolar (fatty) change: like change in liver
lipofuscinosis
-'wear and tear' pigment
-no effect on renal function
-brown to black kidneys
-golden brown pigment in tubular epithelium
-esp. cattle
renal cysts
-smooth, thin walled
-lined by flattened epithelium
-single or multiple (polycystic)
-filled with clear watery fluid
-congenital or acquired
-filtration into blind space
-fairly common
polycystic kidney disease
-congenital, inherited in some breeds
-dogs (assoc. with biliary disease): west highland white terrier, cairn terrier
-cats: persian (~50% - autosomal dominant), burmese
-pigs, lambs: autosomal dominant
hydronephrosis
-chronic obstruction to urinary outflow
-pressure expansion of renal pelvis & calyxes
-pressure atrophy of renal medulla & cortex (eg. from tumor)
-blockage of ureters:
1. uroliathis: by urinary calculi
2. atresia of ureters: congenital
3. inflammatory obstruction of ureters
4. accidental ligation during speying
nematodes of kidneys
-dog: ioctaphyma renale
-pig: stephanurus dentatus
-dog, cat: capillaria plica, capillaria feliscati

-protozoa: kloossiella equi (horse)
juxtaglomerular complex
1. juxtaglomerula cells: modified sm. muscle; renin secretion (response to altered blood flow)
2. macula densa: specialized distal tubular epithelial cells; rein secretion (response to altered [Na])
3. extraglomerular mesangial cells: fxn unknown (renal erythropoietic factor?)
renal hypertension (endocrine response)
1. hypoperfusion (ischaemia)
2. release of Renin from JGA
3. release Aldosterone (adrenal cortex) &/or Angiotensin (liver to lungs to endothelial cells)
4. sodium/water retention in distal tubules (aldosterone) &/or constriction of sm. arterioles (angiotensin)
4. increased BP
renal hypertension
-response to renal ischaemia
-compensatory response to maintain blood flow thru glomeruli (maitain filtration)
-effective response during partial renal ischaemia in acute interstitial nephritis
-chronic hypertension: damage to sm arteries & arterioles --> exacerbates renal hypoperfusion: viscious cycle of progressive renal hypertension
renal hypertension (consequences)
-plasma proteins leak through intima of blood vessels --> deposited in media --> hyalinization, necrosis, occlusion of BVs
-nephrosclerosis (obliteration of glomeruli): replacement fibrosis of renal tubules supplied by efferent glomerular arteriole --> exacerbates hypertensive damage
renal infarction
-distribution of interlobular & arcuate arteries
-ischaemia due to vascular occlusion
-wedge shaped areas of coagulative necrosis
-red, white or pale & shrunken
renal cortical necrosis (bovine)
-mimics infarction
-yellow-grey lesions oin renal cortex
-involves full width of cortex
-microthrombi in blood vessels (vascular compromise)
-difficult to distinguish from pyelonephritis (grossly)
embolic nephritis (bacteraemia & septicaemia)
bacteria trapped in glomerular capillaries:
-colisepticaemia: E. coli
-tick pyaemia: stphylococcus aureus
-bacterial endocarditis: streptococcus spp
-omphalitis: actinobacillus equuli
embolic nephritis (glomerulitis)
-bacterial emboli trapped in glomerular capillaries
-focal necrosis & infiltration by neutrophils
focal embolic nephritis
-bacterial emboli in glomeruli or arterioles
-extensive suppurative inflammation
-abcessation
-chronic pyelonephritis
nephritis associated with vasculitis
systemic viral disease:
1. feline infectious peritonitis (FIP)
2. canine herpesvirus (CHV)
fluid & electrolyte resorption
-PCT: 80-85% of glomerular filtrate
-DST & DCT & CT: remaining 15-20%
-resorption in PCT depends on sodium transport which establish osmotic gradient
-PCT most metabolically active
renin-aldosterone
-renin secreted by JGA in response to:
1. reduced renal blood flow
2. reduced blood sodium concentration (macula densa)
-aldosterone released by adrenal cortex in response to renin: increases sodium resorption in distal tubules
-sodium resorption induces water resorption by distal tubules (concentration of urine)
diabetes insipidus
-failure of production of ADH (by pars nervosa of pituitary): pituitary neoplasm (most frequent)
-lack of response to ADH: absence of receptors (rare) or blockade of receptors (rare)
-collecting tubules remain impermeable to water
-inability to concentrate urine: polyuria, polydipsia
-similar clinical signs to diabetes mellitus but different mechanism
-not very common in domestics
diabetes mellitus
-failure of production of insulin (by beta cells of islets of langerhans in pancreas)
-insulin dependent tissues unable to absorb glucose: hyperglycaemia
-higher concentration of glucose than normal in glomerular filtrate: capacity of tubules to resorb exceeded (glucosuria)
-glucose exerts osmotic effect (draws water): polyuria + polydipsia
polyuria
-production of large quantities of dilute urine
-osmotic effect of increased concentration of solutes in tubules: osmotic diuresis
-caused by:
1. proteinuria: nephrotic syndrome (amyloidosis or membranous glomerulonephritis)
2. glucosuria: diabetes mellitus
3. lack of ADH: diabetes insipidus
4. chronic renal disease with interstitial fibrosis
oliguria (and anuria)
-decreased urine production
-reduced volume of filtrate:
1. dehydration
2. haemorrhagic shock
3. acute tubulointerstitial nephritis
4. urinary calculi: obstruction
regulation of acid-base balance
-H+ excreted as NH4+ or in exchange for Na+
-failure of H+ excretion occurs with renal tubular damage: metabolic acidosis
-urine pH affects solubility of excreted minerals: urinary calculi
renal secondary hyperparathyroidism
-chronic renal disease (esp. tubular interstitial)
-impaired tubular excretion of phosphate: hyperphosphataemia
-altered Ca:PO4 ratio: relative hypocalcaemia
-parathyroid gland stimulated to secrete parathyroid hormone (PTH):
1. resorption of mineral from bone
2. increased phosphate excretion: but PO4 excretion is original problem so phosphate retention continues (continued parathyroid stimulation & resorption of bone) --> viscious cycle with fibrosis & softening of bone
mineral & electrolyte imbalances (vitamin D metabolism)
-renal disease: inability to convert cholecalciferol to calcitriol
-impairs calcium absorption
-deficiency: ricketts, osteomalacia
mineral & electrolyte imbalances (potassium excretion)
-chronic renal disease
-adrenocortical insufficiency: lack of aldosterone (reduced Na+ resorption)
-failure of K+ excretion (exchanged for Na+): hyperkalaemia
-cardiac arrhytmias
-generalized muscle weakness
erythropoiesis
-hypoxia detected in kidneys
-production of erythropoietin: extraglomerula mesangial cells, peritubular cells, JGA?
-chronic renal disease:
1. uraemia: toxic effects on bone marrow
2. reduced erythropoietin: non-regenerative anaemia
renal neoplasia
-primary renal cell carcinoma (from tubular epithelial cells): dogs, cattle, sheep
-lymphosarcoma: cats, cattle
-nephroblastoma: pigs, poultry, fish
-adrenal neoplasia (local extension): dogs
-metastatic neoplasms: high vascularity
cystitis
-inflammation of the bladder
1. trauma: crystalluria/urinary calculi (mechanical damage); urethral catheterization
2. bacterial infection (primary or secondary): ascending (females --> shorter urethra) or descending (pyelonephritis)
bacterial cystitis
-bacterial inflammation of the bladder
-E. coli
-klebsiella spp
-proteus spp (haemolytic strains)
-corynebacterium renale: cattle
-actinobaculum suis: pigs
cystitis (stasis of urine)
-spinal cord paralysis: vertebral fractures, neoplasia, abcesses, intervertebral disc protrusion
-urinary obstruction: calculi or neoplasm (transitional cell carcinoma)
-chemical: neoplasia drugs, ingestion of lucerne hay (horses)
-viral: classical swine fever (petechial haemorrhages), canine distemper (viral inclusion bodies in epithelium)
acute cystitis (gross pathology)
-reddening of mucosa of bladder
-hyperaemia & oedema
-haemorrhagic streaks
-cloudy urine: necrotic epithelium (sloughing), leucocytes
-haematuria: blood in urine
acute cystitis (histopath)
-hyperaemia & oedema
-exudation of neutrophils: pass across mucosa quickly (may not see alot)
-haemorrhage, erosion & ulceration
-bacteria (won't see many)
-crystals embedded in mucosa
-haemorrhagic: in mucosa
-diphteritic: membrane of necrotic epithelium & inflammatory cells
chronic cystitis (gross)
-thickening of wall of bladder: oedema, proliferative fibroplasia
-ulceration with necrotic membrane
-haemorrhages
chronic cystitis (histo)
-fibrovascular hyperplasia: fibrosis
-epithelial hyperplasia: cystitis glandularis
-inflammation: chronic active cystitis (neutrophils, macrophages, lymphocyts & plasma cells)
-haemorrhage, erosion & ulceration
-bacteria
uroliathis (general)
-urinary calculi: uroliths, kidney or bladder stones
-mineralized concretions: precip of crystals from urine, inorganic mineral salts, organic compounds
uroliathis (endogenous precipitates)
1. triple phosphate (struvite): Ca/Mg/NHPO4 (white to gray); most common in dogs & cats
2. carbonate: white to yellow
3. xanthine (organic metabolite): deficiency of xanthine oxidase in cattle & dogs --> failure to absorb; yellow to brown
4. cysteine: cystinura is inherited defect in male dogs (dachshunds); yellow
5. urate: inherited defect in tubular resorption of uric acid (dalmations); yellow to brown
uroliathis (exogenous precipitates)
-grazing animals
1. oxalate: in some plants; white to grey
2. silicate: cattle grazing high silica pasture; brown
3. benzocoumarin: sheep grazing clover pasture; yellow
uroliathis (sites of obstruction: males)
-dogs: poximal os penis
-cats: penile urethra (mucoproteinaceous struvite crystalline plug; feline urological syndrom FUS --> 'blocked cat syndrome'); emergency (bladder may rupture)
-ruminants: ischial arch, sigmoid flexure, ovine urethral process
-males & females: renal pelvis & calyces, urinary bladder
-if in kidney: may get hydronephrosis
uroliathis (predisposing factors)
1. urinary pH
-alkaline (ruminants): phosphates & carbonates precipitate
-acidic (carnivores): oxalate, cystein, urate precipitate
2. dietary intake of minerals: high PO4, oxalate, silica
3. water intake: dilution effect (urinary concentration in dehydration)
4. UTI: alkaline urine, bacteria & necrotic debris act as nidus (precipitate around)
uroliathis (consequences)
-hydronephrosisL obstruction of ureter (unilateral)
-hydroureter: distension of uereter
-uraemia: in acute obstruction kideny fail to filter b/c back pressure
-rupture of bladder: peritonitis (+ uraemia)
-rupture of urethra: cellulitis
-cystitis: mechanical or bacterial
-pyeolonephritis: ascending infection
-local damage: necrosis, inflammation
neoplasia of lower urinary tract
-transitional cell carcinoma (most common)
-squamous cell carcinoma
-adenocarcinoma
-leiomyoma
-leiomyosarcoma
-papillomas: pre-malignant
-polyps
-haemagnioma & haemangiosarcoma
transitional cell carcinoma (bladder)
-invasion of bladder wall: haematuria (blood in urine)
-urethral obstruction: dysuria (difficulty urinating)
-ureteral obstruction: hydronephrosis (if unilateral)
-metastisis to regional lymph notes (sublumbar) & lungs
enzootic bovine haematuria (urinary bladder)
-bracken fern: immunosuppressants & carcinogens
-vascular hyperplasia/ectasia: haematuria
-haemangioma & haemangiosarcoma
-haemangioendothelioma
-transitional cell carcinoma
-papillary carcinoma
-fibroma & fibrosarcoma
-not very commong
anatomical & functional zones of the respiratory system
1. conductive system: nsal cavity, pharynx, larynx. trachea, bronchi
2. transitional system: bronchioles
3. gas exchange system: alveoli
routes of respiratory insult
-inhalation*: particles, aerosols, gases
-haematogenous spread
-local spread
-direct implantation
sources of injury in the respiratory system
-exogenous: bacteria, viruses, fungi, protozoa, parasites
-commensals: mannheimia haemolytica, pasteurella multocida, streptococcus zooepidemicus
-toxins: inhalation (NH3), haematogenous (paraquat, 3-methylindole)
fate of inhaled particles
-deposition mostly depends on particle size
-also: concentration, electrical charge, relative humidity, respiratory rate
deposition of particles in respiratory system (size)
1. >10 micrometers: turbulence by conchae --> nasal mucosa
2. 2-10 micrometers: bifurcation of trachea --> bronchial mucosa
3. 1-2 micrometers: slowing of air in bronchi & bronchioles --> bronchiolar & alveolar mucosa by gravitation or diffusion
4. 0.5-2 micrometers: exhaled
5. <0.5 micrometers: retained due to diffusion forces
NOTE: bacteria & virus are less than 2 micrometers (can reach bronchoalveolar region); long slender fibres (asbestos) may bypass filtration system via laminar flow & reach LRT
respiratory system (clearance mechanisms)
-coughing & sneezing
-mucocilliary blanket
-bronchial associated lymphoid tissue (BALT)
-alveolar macrophages
respiratory epithelium
-pseudostratified ciliated columnar epithelium
-mucous (goblet) cells
-cilliated cells
-brush cells
-basal cells
-serous cells
-neuroendocrine cells
mucociliary blanket
-main defense of nasal cavity, trachea & brochi (conductive system): removes partcles, microorganisms & dissolves toxic gases
-mucus moved to oropharynx & swallowed
-excess mucus from nasal cavity is swallowed, discharged as an exudate or sneezed
-excess mucus from trachea is coughed into oropharynx & swallowed
-mucus (from goblet & serous cells): water & electrolytes, glycoproteins & lipids, immunoglobulins
transitional system: bronchioles
-simple cuboidal epithelium
-loss of ciliated cells & mucous cells
-clara cells: mixed function oxidases & detoxification
respiratory bronchioles (species)
-present: carnivores & monkeys
-weakly developed: horses & humans
-absent: ruminants & pigs
bronchial-associated lymphoid tissue (BALT)
-at bifurcation of bronchi & bronchioles (sites of collision of inhaled particles)
-M (membranous) cells: modified epithelial cells overlying BALT (upatake & transport of particulate antigens)
-hyperpasia in chronic airway disease
-lymphocytes: T (cytotoxic, helper, suppressor) & B (plasma: IgA mostly) cells
-antigen presenting cells (APCs): macrophages & dendritic cells (phagocytose & transport particles & soluble antigen into BALT)
immunoglobulins (respiratory)
1. IgA:
-nasal & tracheal secretions
-plasma cells: nasopharynx, trachea, BALT
-secretory factor
-prevents attachment of pathogens
-opsonization
2. IgG: alveoli
gas exchenage system (pneumocytes)
1. type I pneumocytes: gas exchange
2. type II pneumocytes: surfactant
alveolar macrophages
-main line of defense against inhaled microbial pathogens & inanimate particles
-derived from blood monocytes & interstitial macrophages (histiocytes)
-migrate to bronchioles --> mucociliary blanket
-phagocytosis: attach to & ingest bacteria & particles (lysosomal enzymes destroy bacteria)
-facultative intracellular bacter resist intracellular killing: mycobacterium tuberculosis, Legionella pneumophila, Listeria monocytogenes, Haemophilus somnus, Cryptococcus neoformans
pulmonary intravascular macrophages
-major role in phagocytosis of blood borne microbial pathogens (cats, ruminants, pigs)
-kupfer cells & splenic macrophages: dogs, humans, rodents
impairment of respiratory defense mechanisms (toxic gases)
-ammonia
-hydrogen sulphide
-sulphur dioxide
-nitrogen dioxide
-chlorine
impairment of respiratory defense mechanisms (dust)
-straw/hay/wood shavings
-grain/flour
-dander/feathers
-mites
-faeces
impairment of respiratory defense mechanisms (endogenous)
-uraemia, acidosis, endotoxaemia
-dehydration, starvation
-pulmonary oedema, hypoxia
-anaesthesia
impairment of respiratory defense mechanisms (viral)
-direct damage to respiratory epithelium: reduced mucociliary clearance
-indirect damage to alveolar macrophages: impaired phagocytosis & killing of bacteria
-influenza viruses: horses, pigs
-parainfluenza viruses: cattle, sheep (PI-3)
-herpesviruses: cattle (BHV-1), horses (EHV-1)
-canine distemper virus: dogs
impairment of respiratory defense mechanisms (immunoseppressive viruses)
-secondary bacterial infections
-HIV
-FIV
-canine distemper virus
-lelystad virus (porcine reporductive & respiratory syndrome: PRRS)
-bovine pestivirus (bovine viral diarrhea: BVDV)
-also: immunosuppressive drugs (corticosteroids, cyclophosphamide, azathioprine)
rhinitis (acute)
-serous nasal discharge
-hyperaemia & oedema: reddened mucosa
-exudation of serum & neutrophils
rhinitis (chronic)
-mucopurulent discharge
-oedema
-proliferation of mucosa: thickening
-exudation of neutrophils & mucus
-infiltration by lymphocytes & plasma cells (mononuclear cells)
rhitinits (viral)
-cats: feline herpes virus 1 (feline rhinotracheitis) --> invades ciliated epithelial cells; feline calicivirus
-dogs: canine adenovirus 2, canine parainfluenza virus 2, canine distemper virus
-horses: equine herpes virus 1, equine influenza virus A
-cattle: bovine herpes virus 1 (infectious bovine rhinotracheitis)
-pigs: porcine cytomegalovirus (inclusion body rhinitis)
rhinitis (bacterial)
-often develops secondary to viral rhinits
-suppurative & necrotizing inflammation
bacterial rhinitis (horses)
-strangles: streptococcus equi ss equi
-bastard strangles: strep. zooepidemicus (commensal)
-mellioidosis (tropical): burkholderia pseudomallei
-glanders (URT) & farcy (skin to lymphatics): burkholderia mallei
bacterial rhinitis (dogs, cats, pigs)
-dogs: pasteurella multocida, bordatella bronchiseptica, actiomyces spp
-cats: bordatella bronchiseptical, chlamydophila felis, mycoplasma felis
pigs: pasteurella multocida (type D toxigenic strains --> atrophic rhinitis), bordatella bronchiseptica
cainine infectious tracheobronchitis (kennel cough)
any 1 (or combo) of:
-canine adenovirus 2
-canine parainfluenza virus 2
-bordatella bronchiseptica
feline respiratory diseae complex
-feline herpes virus 1 (feline viral rhinotracheitis)
-feline calicivirus
-chlamydophila felis
-mycoplasma felis
-bordatella bronchiseptica
-also: pasteurella multocida
mycotic rhinitis
necrotizing or granulomatous rhinitis (fungi):
-aspergillus spp: dogs
-penicillium spp: dogs
-cryptococcus neoformans: dogs
-rhinosporidium seeberi: horses, dogs
-conidiobolus cornatus: horses
parasitic rhinitis
-oestrus ovis: sheep nasal bot
-linguatula serrata: dogs
-capillaria aerophila: dogs, cats
-pneumooyssus caninum: dogs
allergic rhinitis
-immediate (type I) hypersensitivity: IgE
-dogs, cattle, cats
-oedema
-infiltration of nasal mucosa by eosinophils
-less common in domestics than humans (hay fever)
nasal foreign bodies
-sticks, grass seeds
-dogs, horses, cats
-epitaxis: bleeding from nose
-chronic rhinitis
neoplasms of nasal cavity (malignant)
-nasal adenocarcinoma
-squamous cell carcinoma
-osteogenic sarcomas
-chondrosarcomas
-fibrosarcoma
-haemangiosarcoma
-osteosarcoma
neoplasms of nasal cavity (benign)
-osteoma
-chondroma
-haemangioma
-nasal polyps
-cysts
neoplasms of nasal cavity (species)
-dogs: adenocarcinoma in nasal pasages(esp. dolicocephalic breeds: collies, GSDs)
-cats: squamous cell carcinoma (locally invasive) in nasal vestibule
enzootic nasal tumor
-sheep & goats
-adenocarcinoma
-caused by retrovirus: enzootic nasal tumor virus (similar to Jaagsiekte sheep retrovirus)
-worldwide except UK, Australia, New Zealand
guttural pouch diseases
-guttural pouch mycosis (fungal): aspergillus nidulans
-guttural pouch empyema (accumulation of purulent exudate): stretococcus equi (strangles)
-chondroids: 'uroliths of guttural pouch
congenital deformitis (larynx)
-epiglottic entrapment
-laryngeal stenosis
-hypoplastic epiglottis
-conformational problems: brachycephalic breeds
laryngeal oedema
-asphyxiation due to:
-allergic diseases/hypersensitivity
-intubation of cats: post-anaesthetic mortality
-brachycephalic breeds: bulldogs
laryngeal hemiplegia
-roaring in horses
-left branch of recurrent laryngeal nerve damaged
-affects: dorsal cricoarytenoid muscle of left arytenoid cartilage
laryngitis
-similar pathogens to rhinits:
-acute & chronic: viral & bacterial
-laryngeal chondritis (texel sheep): abcessation of laryngeal cartilage
-necrotizing larygitis (calves): arcanobacterium pyogenes
-calf diptheria: fusobacterium necrophorum
tracheitis & bronchitis
1. viral
-infectious bovine rhinotracheitis: bovine herpesvirus 1
-infectious laryngotracheitis virus: chickens
2. bacterial:
-bordatella bronchiseptica (dogs, cats): adheres to ciliated epithelium
-bordatella pertussis (humans): whooping cough
tracheal obstructions
-congenital tracheal stenosis: dorosventral or lateral flattening (foals, dogs, cats)
-foreign bodies: inhaled vomit (aspiration pneumonia), aspirated balls, sticks, toyes, bones
-mucus plugs: anaesthesia (esp. cats)
-tracheal necrosis: endotracheal tubes (esp. cats if inflate cuff too much)
-froth: pulmonary oedema
-peritracheal masses: abcesses, neoplasia, goitre, lymphadenomegaly
-parasite: oslerus osleri (dogs), syngamus trachea (chickens)
-papillomas (eg. in oropharynx)
bronchial hypersensitivity reactions
-feline asthma (feline allergic bronchitis)
-chronic obstructive pulmonary disease (COPD) in horses: "heaves" b/c heave line in intercostal muscles; COPD = RAO
-eosinophils, mast cells: type I hypersensitivity (IgE)
-oedema, bronchoconstriction
-fibrovascular hyperplasia
lungs (species differences)
1. lobation: external fissures
-well developed: dogs, cats, cattle, sheep, goats, pigs
-little developed: horses
2. lobulation: CT between lobule
-well developed: cattle*, pigs
-little developed: dogs, cats, sheep, goats
circulatory disturbances of lungs (oedema)
-left sided congestive heart failure: back pressure of blood into lungs
-iatrogenic fluid overload
-hypoalbumaemia: liver disease, nephrotic syndrome (leaky glomeruli), protein losing enteropathy
-pulmonary vascular damage
-pulmonary epithelial damage
-accompanies many inflammatory reactions
circulatory disturbances of lungs (hyperaemia & congestion)
-hyperaemia (active): acute pneumonia
-congestion (passive): congestive heart failure, hypostatic congestion
circulatory disturbances of lungs (ante-mortem haemorrhage)
-trauma
-coagulopathies
-disseminated intravascular coagulation (DIC)
-vasculitis
-septicaemia
-pulmonary thromboembolism
-haemorrhagic pneumonia (eg. mannheimia haemolytica)
circulatory disturbances of lungs (post-mortem)
-blood splashing: aspiration of blood following slaughter
circulatory disturbances of lungs (cor pulmonale)
-right sided congestive heart failure
-secondary to chronic pulmonary disease: chronic interstitial fibrosis, chronic pneumonia, lungworm
-increased resistance in vascular bed of lungs: back pressure into right heart increases pre-load (must work harder)
metabolic disturbances of lungs (calcification)
-hypercalcaemia (metastatic calcification): hypervitaminosis D (over supplementation)
-uraemia: incr. phosphate in renal disease (renal secondary parathyroidism)
-pulmonary necrosis (dystrophic calcification)
-"old dog" calcification: no pathological significance
-mineralization of basement membranes
-heterotropic ossification
congenital defects of lugns
-accessory lung tissue
-pulmonary hypoplasia/agenesis
-plumonary hamartoma: malformation
-congenital emphysema/bronchiectasis
-ciliary dyskinesa: immontile cilia syndrom
-pulmonary melanosis: incidental
abnormalities of inflation
-emphysema: overinflation
-atelectasis: failure of inflation/collapes (congenital or acquired)
emphysema
-over inflation
-alveolar emphysema
-interstitial emphysema
-bullous emphysema: large pockets
pleural effusions
-excess pleural fluid
-hydrothorax (serous): congestive heart failure, thoracic neoplasia, iatrogenic (fluid overload caused by vet)
-haemothorax: trauma, coagulopathies
-chylothorax (lymph): ruptured thoracic duct, trauma
-NOTE: can get atlectasis (acquired) from compressive effects
congenital atelectasis
-lungs never inflate
-perinatal mortality
-meconium aspiration syndrome: obstruction of airways by amniotic fluid or meconium ("foetal distress": difficult/prolonged birth)
-neonatal respiratory distress syndrome (RDS): premature birth (lack of corticosteroids to promote lung maturation); immature type II pneumocytes (insufficient surfactant); "wanderers" in foals (cerebral hypoxia); "hyaline membrane disease"
empyema/pyothorax
-purulent exudate in thoracic cavity
-bacterial infection (occasionaly mycotic)
-cattle, sheep, pigs: suppurative pneumonia & pleurisy; mediastinal abcesses in cattle
-cats, horses: idiopathic
pleurisy (pleruitis)
-suppurative: purulent exudate
-fibrinous: exudation of fibrin
-fibrinosuppurative: pneumonia
-chronic proliferative
-bacterial infection of pleural surfaces: eg. pigs --> glasser's disease (haemophilus parasusis)
acquire atelectasis (compressive)
lung collapse from space occupying lesion:
-neoplasia
-bloat (ruminants)
-diaphragmatic hernia: trauma or gongenital (eg. liver into thoracic cavity)
-hydrothorax: congestive heart failure, fluid overload (vet)
-haemothorax: trauma, coagulopathies
-pneumothorax: trauma, rupture bullae, penetrating injuries
-chylothorx (lymph): ruptured thoracic duct, trauma
acquired atelectasis (obstructive)
-areas supplied by block airways will collapse
-exudates: bronchopneumonia
-aspirated foreign material
-parasites: lungworm
-neoplasia
-mucosal oedema: allergies/asthma
pneumothorax
-trauma
-ruptured bullae
-penetrating injuries
-secondary to other lung disease
-iatrogenic: positive pressure ventilation
-may cause compresseve atelectasis
lung consolidation
-portions of lung become solidified: dense, heavy & wet
-often due to inflammatory infiltrates: alveoli & interstitial tissue
-usually accompanied by loss of air spaces
-often oedema
-may be caused by or accompanied by collapse (atelectasis)
-red consolidation: hyperaemia, oedema, cellular infiltrate
-grey consolidation: cellualr infiltrate
pneumonia
-pneumonia: inflammation of lungs
-pneumonitis/interstitial pneumonia: inflammation of pulmonary interstitium (not airways)
-pleurisy (pleuritis): inflammation of pleura
-pleuropneumonia: inflammation of lungs & pleura
-NOTE: can't separate out interstitial disease from alveolitis
pneumonia (classification by aetiology)
-bacterial: eg. mannheimia haemolytica
-viral: eg. canine distemper virus
-verminous: eg. dictyocaulus viviparus
-mycotic: eg. aspergillus fumigatus
-toxic
-allergic
pneumonia (classification by pathology)
-bronchopneumonia: via inhalation
-embolic pneumonia: via BVs
-interstitial pneumonia
-granulomatous pneumonia
enzootic
present commonly at low levels
pneumonia (classification by epidemiology)
1. enzootic pneumonia:
-pigs: mycoplasma hyponeumniae (enzootic pneumonia of pigs)
-sheep: mannheimia haemolytica
-cattle: viral pneumonias
2. atypical pneumonia:
-sheep: mycoplasm ovipneumonia (esp. overwintered inside)
-cattle: mycoplasma bovis
pneumonia (discriptive terms for distribution of lesions)
-cranioventral: common for inhaled pneumonia (eg. mycoplasma)
-lobar (eg. pasteurella multocida)
-focal or multifocal: usually caudodorsal b/c more BVs (eg. embolic)
-diffuse or generalized
pneumonia (types of exudation)
-suppurative
-fibrionous
-haemorrhagic
-necrotizing
-lymphocytic (cuffing)
-granulomatous
-eosinophilic
pneumonia (duratin)
-acute: oedema, fibrin, haemorrhage, necrosis (neutrophils & macrophages)
-chronic: degenerate neutrophils & macrophages, abcessation, lymphocytes & plasma cells, fibrosis
bronchpneumonia
-most common
-inhaled agent concentrates in bronchioles 1st (esp. terminal bronchioles) then spreads to surrounding alveoli
-cranioventral distribution of lesions
bronchopneumonia (bacterial)
-acute suppurative: pasteurella multocida (pigs, cattle, sheep), streptococcus spp (dogs, cats), bordatella bronchisptica (dogs, cats, pigs: adheres to ciliated epithelial cells)
-gross: consilidation (firm/heavy, loss of air spaces, inflammatory exudates (fluid), atelectasis)
-histo: neutrophils & macrophages in bronchioles (initially) & alveoli, inflammation of bronchioles, hyperaemia, alveolar oedema
aspiration pneumonia
-inhaled foreign bodies
-inhaled vomitus: weak/sickened animals, anaesthesia
-hand feeding puppies & kittens
-incorrect stomach tubing (horses)
acute fibrinous bronchopneumonia (bacterial)
-cranioventral distribution
-pasteurella multocida: pigs, cattle, sheep
-mannheimia haemolytica: cattle, sheep
-actinobacillus pleuopneumonia: pigs
-streptococcus spp: dogs, cats
chronic suppurative bronchopneumonia (bacterial)
-pasteurella multocida: pigs, cattle, sheep
-arcanobacterium pyogenes: cattle, sheep
-fusobacterium necrphorum: cattle
-corynebacterium pseudotuberculosis: sheep
-gross: nodular lesions with suppurative foci, mucopurulent exudate in bronchioles
chronic suppurative pneumonia
-chronic bronchopneumonia: cranioventral, suppurative exudates in bronchi/bronchioles
-pulmonary abcessation: ventral lung border
-bronchiectasis: dilation of airways with mucopurulent exudate
-fibrosis (interstitial): cor pulmonale
lymphocytic bronchopneumonia ("cuffing" or "chronic" pneumonia)
-mononuclear cell accumulation around bronchioles
-pigs: mycoplasma hypopneumoniae
-sheep: mycoplasma ovipneumoniae
cattle: mycoplasma bovis (enzootic pneumonia of calves)
-also: some viral bronchopneumonias
mycoplasmal bronchopneumonia
-lymphocytic bronchopneumonia ("cuffing" or "chronic" pneumonia)
-consolidation of cranioventral lobes
-sharp line of demarcation from inflated lung
-acute/subacute bronchopneumonia: dark red
-chronic cuffing pneumonia: grey, purple or red
-lymph nodes enlarge
-histo: peribronchiolar lymphoid hyperplasia (cuffing): infiltration by lumphocytes & plasma cells
embolic pneumonia
-perdominantly caudodorsal distribution (b/c larger blood supply)
-bacterial emboli release from suppurative foci: eg. umbilical abcesses ("naval ill"), valvular heart disease, tail biting
-often suppurative or necrotizing lesions
thrombosis of caudal vena cava (ruminants)
-grain overload --> lactic acidosis
-ruminitis --> bacterial seeding of liver (via portal circulation)
-hepatic abcesses: may get walled off & remain quiescent for years
-extension to caudal vena cava --> lungs
-embolic suppurative pneumonia
pulmonary tuberculosis
-bovine tuberculosis: mycobacterium bovis (badger is resevoir)
-human TB: mycobacterium tuberculosis
-granulomatous lesions on pleura
-histo: epitheloid macrophages (+ lymphocytes & plasma cells), multinucleate giant cells (langerhans cells), caseous necrosis
-NOTE: NOT mycoplasm
acute viral pneumonia
-bronchoalveolar pneumonia (aka bronchointerstitial pneumonia)
-necrotizing bronchiolitis: bronchiolar epithelium
-necrotizing alveolitis: alveolar type I pneumocytes
-interstitial infiltration/pneumonitis: macrophages, neutrophils (mild compared to bacterial)
chronic viral pneumonia
-pneumonitis
-non-suppurative interstitial pneumonia: lymphocytic infiltrates
-atypical interstitial pneumonia: alveolar epithelial hyperplasia (type II pneumocytes re-epithelialize alveoli), hyaline membrane formation (mix of cellular debris & proteinaceous material)
viral pneumonia (cattle)
-parainfluenza virus type 3: cytoplasmic inclusions
-bovine respiratory syncytial virus
-bovine adenovirus
-bovine herpesvirus type 1 (infectious bovine rhinotracheitis): intranuclear inclusions
viral pneumonia (cats)
-feline herpesvirus type 1 (feline rhinotracheitis): intranuclear inclusions
-feline calicivirus
-feline coronavirus (feline infectious peritonitis: FIP): originates as necrotizing vasculitis
viral pneumonia (dogs)
1. canine distemper virus:
-systemic viral infection
-generalized, diffuse interstitial pneumonia
-eosinophilic cytoplasmic inclusions (& nuclear)
-replication in lymphoid tissue: reaches lung via blood (diffuse)
-immunosuppressant: secondary bacterial infections
viral pneumonia (ruminant lentiviruses)
-maedi/visna virus: sheep
-caprine arthritis-encephalitis virus: goats
-retroviruses: persistent infections
-immune mediated disease
-lymphoid interstitial pneumonitis
-lungs fail to collapse: rubber, sponge-like
-very generalized (diffuse): increased density & infiltration of lymphocytes
lungworms (cattle, sheep, pigs)
-cattle: dictyocaulus viviparus (wedge shaped consilidation in caudal lungs)
-sheep:
1. dictyocaulus filaria (caudal): eggs cause intertitial rxn; adults in bronchioles; lymphoid & eosinophilic infiltrates
2. muelleris capillaris (dorso-lateral surface of caudal lobes): lead shot lesions (immune) are granulomas (lymphocytes & plasma cells)
-pigs: metstrongylus apri
lungworms (dog & cat)
-cats: aelurostrongylus abstrusus
-dogs: capillaria aerophila
mycotic pneumonia
-mostly birds
-aspergillosis
-embolic & granulomatous forms
toxic pneumopathies
-interstitial pneumonia (toxic damage to type I pneumocytes & hyperplasia of type II pneumocytes)
-affect all parts of lung (generalized/diffuse)
-fog fever (atypical pneumnia): cattle (L-trytophan --> 3-methylindole)
-chemical toxicity: paraquat (herbicide)
bovine farmer's lung
-allergic interstitial pneumonia (hypersensitivity pneumonia)
-spores of saccharopolyspora rectivirgula (micropolyspora faeni)
-also aspergillus fumigatus
-eosinophils & lymphocytes (intestitial)
-alveolar (intralobular) emphysema: may develop small bulli
-COPD (RAO) in horses
-not common in domestics
-less common b/c more silage & less hay
diffuse fibrosing alveolitis (DFA)
-non specific response to chronic lung injury
-atypical interstitial pneumonia: verminous, chronic viral, or toxic insults
-cor pulmonale: rt sided congestive heart failure
-diffuse alveolar damage (DAD)
pulmonary neoplasia
1. primary:
-bronchogenic carcinoma: originate in bronchiole
-bronchioloalveolar carcinoma: originate @ jxn of terminal bronchiole & alveolus
-adenocarcinoma: eg. Jaagsiekte in sheep
2. secondary (metastatic): b/c entire blood volume goes thru lungs
-mammary carcinoma: cats & dogs
-thryroid carcinoma: cats
-haemangiosarcoma: dogs
3. pleural
-mesothelioma: assoc. with asbestos
-thymic lymphosarcoma
-pulmonary carinomatosis: spread across pleura b/c can't find a primary site
ovine pulmonary adenocarcinoma (Jaagsiekte)
-means "driving sickness" in Afrikaans
-retrovirus --> adenocarcinoma
-infection of type II pneumocytes & clara cells: produces xs surfactant
-froth in airways
-tubulopapillary prolferation of epithelial cells
-only known infectious source of lung cancer
skin (functions)
-protection from environ (str. corneum): fluid loss, bugs, chemical, physical injury
-temp & BP regulation (hair coat, sweat glands, blood supply): sweating, heat conservation
-sensory perception: tactile hairs, merkel cells, nerves
-secretory function: produces VitD
skin (normal layers)
1. epidermis:
-stratum corneum
-(stratum lucidum)
-stratum granulosum
-stratum spinosum
-stratum basale (single layer)
2. dermis: sebaceous glands, apocrine sweat glands, hair follicles, arrector pilli muscles, vascular plexus
3. subcutus: fat, fibrous tissue
skin (dermis)
-collagen fibres, elastin fibres, glycosaminoglycan ground substance
-hair follicles
-glands: sebaceous, apocrine, eccrrine (foot pad)
-BVs, lymphatics, nerves
-mast cells, lymphocytes, plasma cells, macrophages
examination of skin (methods)
-tape impression
-combing & brushing
-hair pluck (trichogram)
-skin scrape: superficial or dep
-skin biopsy: punch or excision (more useful)
epidermal response to injury
1. str. corneum: hyperkeratosis
-orthokeratosis: no nuclei
-parakeratosis: with nuclei
2. str. granulosum: hypergranulosis (incr. keratohyaline granules)
3. str. spinosum
-hyperplasia/acanthosis: thickening
-spongiosis: intercellular oedema
4. pigmentation: hyper or hypo (melanocytes)
-lichenification: callus
dermatitis
non-specific cutaneous inflammatory reaction with changes in epidemis & dermis
signs of skin inflammation
-redness (rubor)
-heat (calor)
-swelling
-pain
-loss of function
acute dermatitis
-vasodilation: hyperaemia/erythema
-increased vascular permeability: plasma leakage, inflammatory oedema
-migration of phagocytic leucocytes: neutrophils & macrophages
-gross lesion: vesicles, papules, erythema, oedema, exudation
-microscopic lesions: spongiosis (spongioitic vesicles), intracellular oedema, leucocyte exocytosis, vasodilation, perivascular inflammatory cells
chronic dermatitis (cellular response)
-persistent/recurrent acute dermatitis
-immune response: lymphocytes, plasma cells
-phagocytosis: macrophages
-repair: fibroblasts
chronic dermatitis (lesions)
-gross: scale, crust, mild erythema, lichenification, pigment alteration
-histo: hyperkeratosis (ortho or para), acanthosis, dermal oedma (mild to moderate), vasodilation (perivascular inflammatory cells)
primary skin lesions
-develop spontaneously due to underlying disease
-useful to determine aetiology & pathogenesis
-pustule, vesicle, papule (eg. lumpy wool), bulla (big vesicle)
-nodule (papule >1cm), cyst, plaque (raised & flatted w/ crusty surface)
-wheal, tumor (large, raised, firm), macule (color change, small, not raised)
-alopecia (hair loss), altered pigmentation
secondary skin lesions
-self trauma, external factors
-complicate picture & make diagnosis difficult
-epidarmal collarettes, scars, excoriation
-scale, crust, licheification, comedones
-alopecia, altered pigmentation
approach to inflammatory skin case: pattern analysis
-perivascular dermatitis (most common): inflammatory cells coming out of vessels
-interface dermatitis: at dermal-epidermal jxn
-vasculitis: inflammatory cells attacking endothelium
-nodular and/ord diffuse: granulomatous inflammation
-interaepidermal vesicular/pustular dermatitis
-subepidermal vesicular/pustualr dermatitis
-folliculitis & furunculosis (licking): inflammation of hair follicle
-panniculitis: inflammation of subcutis
aetiology of skin conditions
-mnemoic: DAMNIT
-Developmental
-Autoimmune
-Metabolic
-Neoplastic/nutritional
-Inflammatory, infectious, idopathic, iatrogenic
-Traumatic/toxic
skin diseases (general)
1. physical damage: self trauma, actinic dermatitis (UV light)
2. immune mediated: hypersensitivity, autoimmune
traumatic skin diseases (general)
1. direct:
-friction (eg. wrinkled skin, lick dermatitis)/ pressure (eg. obese animals lying around)
-chemical: irritant contact dermatitis
-heat: burns
-light: phototoxicity
2. indirect: metabolic (photosensitivity)
burns
1. partial thickness burns:
-1st degree: epidermis only (erythema & oedema)
-2nd degree: epidermis & part of dermis (vesicle formation)
2. full thickness burns:
-3rd degree
-4th degree: includes subcutaneous fascia
moderate heat dermatosis
-chronic exposure to temp too low to cause thermal burns: heat pads, heated kennel mats, concrete driveways
-irregular area of erythema, hyperpigmentation, alopecia
-occasionally in dogs & cats
actinic dermatitis
-reaction to UVb: eg. white cat in sun
-acanthosis, hyperkeratosis
-crust: serocellular (neutrophils & cell debris)
-pigmentation
-squamous cell carcinoma: rete peggin extending through basement membrane, pigmentary incontinence, loss of normal cell orientation
photosensitization
-photodynamic agents activated by light
-excitation of molecule +/- interaction with O2 (free radicals)
-release inflammatory mediators
-erythema, oedema
-exudation/crusting
-necrosis of sparsely haired, unpigmented skin
-often problem with white area of cattle
photosensitization (types)
1. primary (type I): eg. st. john's wort (photodynamic agent)
2. type II:
-inherited enzyme deficiency: abnormal synthesis of photodynamic agents
-eg. bovine congenital porphyria: teeth & bones stained brown (pink tooth!)
3. type III (hepatogenous): most common
-impaired capacity of liver to excrete phylloerythrin (chlorophyll breakdown product)
-secondary to generalized hepatocellular damage, inherited hepatic defects or bile duct obstruction
hypersensitivity reactions
-type I: immediate (anaphylactic)
-type II: cytotoxic
-type III: immune complex mediated
-type IV: cell-mediated (delayed)
type I hypersensitivity
-flea bite, midge bite, atopy, food allery, uticaria
-production of antigen specific IgE
-IgE bound to mast cell membranes
-reexposure to antigen --> mast cell degranulation
-result: pruritis (itching), self-trauma, eosinophils & mast cells
canine atopy
allergic inhalant dermatitis (type I hypersensitivity)
-pruritic dermatitis & conjuctivitis: face, feet, ventrum
-alopecia, lichenification, hyperpigmentation
-cairns, westies, scotties
-complicated by self trauma
flea bite hypersensitivity (flea allergy dermatitis)
-type I hypersensitivity +/- type IV (delayed)
-common: esp. summer & autumn
-pruritic papular dermatitis (allergic miliar dermatitis)
-lesions: dorsal lumbrosacral area, neck, inner thighs, abdomen
-papules + scale & crust
histo: +/- eosinophils
-"sweet itch": midge bite hypersensitivity in horses
type IV hypersensitivity
-cell mediated (delayed)
-allergic contact dermatitis, flea allergy, drug eruption, tuberculosis diagnosis (TT)
-incomplete antigen (hapten) combines with tissue protein
-complete antigen processed by macrophages
-T lymphocytes are sensitized
-reexposure to antigen --> lymphokines release
-don't need many fleas if sensitive
allergic contact dermatitis
-type IV hypersensitivity (delayed)
-variably pruritic maculopapular dermatitis
-sparsely haired surfaces (esp. ventrum)
-also feet, legs, perineum, scrotum, chin, pinnae
-primary lesion: erythematous patch
-secondary lesion: erythematous reaction
-ventral location: lying on irritant
-histo: acanthosis, perivascular dermatitis, pigmentary incontinence, keratin compacted
-not very common
type III hypersensitivity
-immune complex mediated
-cutaneous vasculitis (erosion & haemorrhage), drug eruption, bacterial (staph) hypersensitivity, porcine dermatopathy & nephropathy syndrome (PDNS)
-depositoin of Ag-Ab complexes (antigen excess) in blood vessel walls
-compement fixation & neutrophil chemotaxis
-tissue damage due to proteolytic & hydrolytic enzymes
type II hypersensitivity
-pemphigus (vesicles in epidermis), pemphigoid, drug eruption
-binding of antibody (IgG or IgM) +/- compliment
-IgG gets between cells causing subcorneal vescicles: loss of adhesion between epidermal cells (fills with neutrophils)
-cytotoxicity or cytolysis
pemphigus
-type II hypersensitivity
-IgG deposited between cells in epidermis
-loss of adhesion of epidermis & dermis: get pustules (filled with neutrophils)
-epidermis lifted & may slough off
-pemphigus foliaceus, pemphigus vulgaris (deeper)
viral skin infections (effects)
-degeneration/necrosis of epithelial cells: 'balloon degeneration' --> vesiculation (blisters)
-stimulation of cell proliferation: papillomatous hyperplasia (wart), hyperkeratosis (canine distemper --> 'hardpad')
-stromal rxn: inflammation, fibroblast activity
-eg. FMD (picornavirus), orf (parapoxvirus), cowpox (orthopoxvirus), cat pox (feline cowpox), pig pox (suipoxvirus), bovine papular stomatitis (parapoxvirus), pseudocowpox (parapoxvirus): vesiculation
-eg. bovine papillomavirus (BPV): cattle, equine, dogs(sarcoids)
equine sarcoids
-non productive infection by bovine papilloma virus (BPV): hyperplastic but no active virion
-fibroblastic skin tumors (30% of all equine skin tumors): proliferative fibrious lesions (hyperplastic epidermis w/ deep rete pegs)
-BPV I & II
-
pyoderma (pathogenesis)
-skin disease caused by pus
1. skin damaged allowing bacterial entry (often staph/strep): often through hair follicles
(furunculosis)
2. thickening of follicle & plugging with keratin at surface
3. follicular acanthosis (bacteria in wall)
4. hair pushed out of follicle & down into dermis (foreign body): macrophages & neutrophils (some lymphocytes & plasma cells)
5. may develop to systemic disease: potentially fatal
pyoderma (types)
-skin disease characterized by purulence
1. surface: most superficial layers of epidermis
2. superficial: skin down to level of intact hair follicles
3. deep: extends to tissues deeper than the follicle --> may involve subcutaneous tissue (painful & hard to treat)
surface pyoderma
1. acute moist dermatitis: hotspot (eg. flea allergy)
-pyotraumatic dermatitis
-environmental dermatitis
2. skin fold dermatitis (subgroup): intertrigo
photosensitization (types)
1. primary (type I): eg. st. john's wort (photodynamic agent)
2. type II:
-inherited enzyme deficiency: abnormal synthesis of photodynamic agents
-eg. bovine congenital porphyria: teeth & bones stained brown (pink tooth!)
3. type III (hepatogenous): most common
-impaired capacity of liver to excrete phylloerythrin (chlorophyll breakdown product)
-secondary to generalized hepatocellular damage, inherited hepatic defects or bile duct obstruction
hypersensitivity reactions
-type I: immediate (anaphylactic)
-type II: cytotoxic
-type III: immune complex mediated
-type IV: cell-mediated (delayed)
type I hypersensitivity
-flea bite, midge bite, atopy, food allery, uticaria
-production of antigen specific IgE
-IgE bound to mast cell membranes
-reexposure to antigen --> mast cell degranulation
-result: pruritis (itching), self-trauma, eosinophils & mast cells
canine atopy
allergic inhalant dermatitis (type I hypersensitivity)
-pruritic dermatitis & conjuctivitis: face, feet, ventrum
-alopecia, lichenification, hyperpigmentation
-cairns, westies, scotties
-complicated by self trauma
flea bite hypersensitivity (flea allergy dermatitis)
-type I hypersensitivity +/- type IV (delayed)
-common: esp. summer & autumn
-pruritic papular dermatitis (allergic miliar dermatitis)
-lesions: dorsal lumbrosacral area, neck, inner thighs, abdomen
-papules + scale & crust
histo: +/- eosinophils
-"sweet itch": midge bite hypersensitivity in horses
acute moist dermatitis (hot spot)
-surface pyoderma
-flea allergy: labradors
-subcorneal pustules
-often green smelly exudate & matted coat: serocellular crust (neutrophils & debris)
-acanthosis
-dogs with long thick coat or in hot areas
superficial pyoderma
-superficial pustular dermatitis: impetigo (NOT intertrigo)
-mostly in armpits & crotch
-superficial folliculitis
-subcorneal pustules
dermatiphilosis
-"rain scald" in horses & "lumpy wool" in sheep
-dermatophilus congolensis (actinomycete)
-superficial, crusted dermatitis
-hyperkeratosis, acanthosis
-alternate layers of hyperkeratotic/parakeratotic cells and degenerate neutrophils
-hyperplastic superficial perivascular dermatitis
-large animals standing in rain/mud
-"paintbrush lesions"
deep pyoderma
-necrotizing folliculitis/furunculosis (including callus pyoderma)
-anal furunculosis
-pododermatitis: between toes
-follicle ruptures --> hair into dermis: foreign body
-pyogranulomatous reaction around hair fragments (macrophages & neutrophils)
-tracking lesions into deep dermis (cellulitis): serocellular crust in hair/skin over lesions
-often working dogs: foreign bodies (esp. between toes)
bacterial infections of skin (others)
1. feline leprosy (mycobacterium)
-granulomatous nodular cutaneous infection
-1 to 3 y/o
-acid fast bacilli (make sure is not TB)
2. actinobacillus
-A. lignieresii
-commensal in mouth
-thick walled abcesses on head, neck, mouth, limbs
superficial mycoses
-fungal/yeast infections involving superficial layers of skin, hair & nails
1. dermatophytosis (ringworm): microsporum, trichophyton (stays w/in keratinized layers --> superficial)
2. dermatomycosis (yeast infection): malassezia (often isolated from skin & external ear)
malassezia dermatitis
-yeast: malassezia pachydermatis
-axilla (armpit)
-yeast bodies in skin smear
-shetland sheepdog
skin conditions (miscellaneous)
-parasitic
-endocrine related
-genetic disorders of hair growth
-skin neoplasms
-nutritional/metabolic
hypotrichosis
decreased hair production
demodicosis
-demidex infection: cigar shaped mite
-proliferates in hair follicle: can damage/plug & cause rupture (furunculosis)
-perifollicular inflammation
-hyperkeratosis/acanthosis
-hyperplasia of follicular epithelium
-granulomatous response to mite fragments
-localized (mild) & generalized (more severe) forms
-pustular demodicosis: crusted, alopecic lesions
sarcoptic mange
-sarcoptes scabiei mite
-more superficial than demodex: easier to treat
-mate on epidermal surface --> female burrows into epidermis (eggs/faeces) --> larvae bore to surface: hyperkeratosis/acanthosis
-dog: patchy alopecia & erythema of pinnae, ventral limbs, trunk; papule with exudation &/or haemorrhage
-superficial dermatitis with subcorneal pustule (tunnel)
mange (others)
-notoedric mange (cat): thickening & crusting of pinnae & facial skin
-chorioptic mange (cow): erythema, exudation & crusting of skin & pastern
-chorioptes equi
skin disease (other parasites)
-louse infestation: pediculosis (eg. flicola sbrostratus --> cat louse)
-harvest mites (brombicula autumnalis): paronychia in dogs (where nail meets skin)
-ticks
-maggots: chew through tissues (eg. blow fly strike)
alopecia (categories)
1. endocrine related: follicle keratosis, dilation & atrophy
2. genetic: follicle dysplasia
3. (inflammatory, immune mediated, neoplastic)
endocrine pattern alopecia
-follicular atrophy & keratosis
-mainly telogen hair follicles (resting phase)
-also hyperkeratosis, epidermal hyperpigmentation
endocrine alopecia (examples)
1. pituitary dwarfism (GSD): nonfunctional adrenal cortex
2. cushing's syndrome (hyperadrenocorticism):
-not pruritc
-get comedones (thin walled follicles packed with sebum & keratin)
-epidermal atrophy
-some degeneration of dermal collagen
-iatrogenic: 'fragile skin syndrom'
3. hypothyroidism: epidermal atrophy, mix oedema (increase mucin in ground substance)
color mutant alopecia
-'blue doberman syndrome'
-partial alopecia of blue-black areas
-pigmentary incontinece
-clumped pigment in hair
common tumors of skin
1. benign: histiocytoma (usually regress, skin adnexal tumors
2. intermediate: mast cell tumors
3. malignant: cutaneous lymphosarcoma, squamous cell carcinoma (white cat in sun)
sebaceous adenoma
-dome shaped/papillated mass: usually on head
-well differentiated cells with distinct border between tumor & normal skin
-good prognosis
-westies
mast cell tumors
-alopecic, erythmatous, oedematous
-any age (avg 8 y/o)
-histo: fried egg appearance
-intermediate aggressiveness: can spread if don't exise entire tumor
-boxers & boston terriers
squamous cell carcinoma
-white cat in sun
-malignant
cutaneous lymphosarcoma
-B & T cell
-often multifocal, nodular or plaque-like lesions
-superficial lymph nodes, systemic involvement possible
-can be malignant
-picture in notes: on toe
nutritional/metabolic skin diseases
1. mineral imbalance:
-zinc responsive dermatosis (siberian husky & alaskan malamute)
-lethal acrodermatitis of bull terriers: inherited zinc absorption & metabolism defects
2. amino acid deficiency: hepatocutaneous syndrome
zinc-responsive dermatosis
-periorbital crusting
-thickening, hyperpigmentation, crusting, alopecia
-peaks of orthokeratotic hyperkeratosis
-siberian husky & alaskan malamute
lethal acrodermatitis
-yellow crusts adhere to alopecic, erythemitous skin
-autosomal recessive defects in zinc (& copper) absorption & metabolism (bull terrier)
-starts in foot pads: distorted swollen foot, crusted & fissured pads, erythema
hepatocutaneous syndrome
-border collies
-crusted, fissured footpads + erythema
-liver: early cirrhosis
-histo: massive, diffuse parakeratosis; hydropic degeneration of upper epidermis; pattern = red, white (vacuolizatoin), blue (hyperplasia)
external ear canal
1. skin
-stratified squamous epithelium
-adnexal structures: sabaceous glands, apocrine glands, hair follicles
2. glands
-sebaceous glands below epithelium
-apocrine glands deeper in dermis
3. ear wax
conditions affecting the external ear (general)
1. pinna
-ectoparasitism: eg. sarcoptic mange (exudation, crusting, erythema, acanthosis)
-bacterial infections
-autoimmune disease: eg. pemphigus (type II hypersensitivity)
-trauma: eg. haematoma, ear tag yanked out
-neoplasia: squamous cell carcinoma (tumor recurrence)
2. external ear canal
-otitis externa: inflammation of external ear (may extend to affect pinna)
-neoplasia
conditions affecting the external ear (specific)
1. sarcoptes scabiei: serocellular crusting, acanthosis, erythema (female tunnels to lay eggs)
2. mycoptes msculinus (skin mite of mouse): orthokeratosis, superficial
3. dermatophilosis (sheep 'lumpy wool')
4. sweet itch: type I hypersensitivy to midge bites (horse)
5. erysipelas: ischaemic necrosis (vasculitis eroding BV walls & occluding)
6. pemphigus foliaceous: type II hypersensitivity (IgG complexes between cells of epidermis) causing crusting & erythema + subcorneal pustules
otitis externa (definition)
-acute or chronic inflammation of the epithelium of external ear canal
-may involve parts of pinna
-multifactorial
otitis externa (causes)
1. ear conformation: long eared & hairy eared
2. swimmers: yeast infections (candida albicans & malassezia pachydermatis)
3. parasites: ear mites (ototdectes cynotis)
4. tumors, polyps: can occlude ear canal
5. extension of middle ear infections and external skin diseases
6. foreign bodies
otitis externa (pathogenesis)
-inflammation
-increase curiminous (apocrine) gland secretion: thick & oily
-accumulation of inflammatory exudate & ceruminous secretions: wet/moist
-irritation & thickening: less air
-trauma (self)
-further irritation
otitis externa (histo)
-epithelial hyperplasia
-cells infiltrate dermis: neutrophils, lymphocytes, plasma cells, macrophages
-chronic: fibrosis & organization of exudates (solidification)
otitis externa (infections)
-parasites: otodectes (cigar shaped ear mite) & psoroptes (mange)
-bacteria: proteus spp, pseudomonas spp (smelly), styphylococcus spp
-yeasts: swimmers
-foreign bodies
atopy
allergic hypersensitivity affecting parts of the body not in direct contact with the allergen
otitis externa (para-aural abcess/cellulitis)
-can develop if ear canal is blocked
-infection tracks to surface
otitis externa (chronic self-trauma)
-erythema, scale, lichenification
-focal pyotraumatic dermatitis & hair loss
otitis externa (cat ceruminous cysts)
-blue color is typical of sweat gland cysts
-histo: dialation of sweat (ceruminous) glands: packed with secretion
tumors of external ear
-auricular skin: squamous cell carcinoma
-ceruminous glands: adenoma (benign), carcinoma (malignant)
-auricular cartilage: chondroma (benign), chondrosarcoma (malignant)
-NOTE: even if benign it takes up space & makes for difficult access
otitis media (tympanic bulla)
1. bacteria (most common): arcanobacteria pyogenes, mannheimia spp, pneudomonas spp
2. fungi/yeasts: aspergillus, candida spp, malassezia spp
3. routes of infection: auditory tube (pharyngitis: pigs, cattle), otitis externa (dogs, cats)
otitis media (consequences)
-otitis interna: meningoencephalitis (abcessation into cerebellum)
-pharyngitis: pneumonia (goes down eustacean tube)
-nasopharngeal polyps (cats)
-eustachitis (pigs) & guttural pouch infection (horses)
otitis interna (labyrinthitis)
-cochlea: impaired hearing/deafness
-vestibular apparatus: loss of balance, nystagmus, head tilt
-auditory nerve (vestibulocochlear nerve = CN VIII): meningitis, encephalitis, facial nerve neuritis (CN VII)
impaired hearing / deafness
-organ of corti: sensory organ of hearing
-detection very difficult in animals: electrodiagnostic testing
-loud noise: hair cell necrosis (doesn't regenerate)
-ototoxic chemicals: aminoglycoside antibiotics, diuretics
vestibular dysfunction
-clinical signs: head tilt, falling towards affected side, ataxia, nystagmus
-lesion location: brain (central), vestibular apparatus (peripheral), both
palatoschisis
-cleft palate
-failure of fusion of soft &/or hard palate
-genetic/idiopathic
-toxic: corticosteroids
-failure to suck
-aspiration pneumonia
-rarely possible to repair
cheiloshisis
-cleft lip, hare lip
-failure of fusion of philtrum
-not as common as cleft palate
tongue (developmental anomolies)
1. lethal lossopharyngeal defect (rare)
-"bird tongue"
-dogs
-inability to suck
2. epitheliogenesis imperfecta (calves)
3. (epithelial fringes: normal in piglets, puppies, kittens)
inflammation of oral cavity
1. stomatitis: oral cavity
2. cheilitis: lips
3. gigivitis: gums
4. glossitis: tongue
5. palatitis: hard or soft palate
6. sialoadenitis: salivary glands
7. tonsilitis: tonsils
8. pharyngitis: pharynx
inflammation of oral cavity (stomatitis)
1. vascular changes: hyperaemia, reddening oedema
2. haemorrhage: petechiae (pinpoint), ecchymoses (patchy)
3. mucosal lesions: acanthosis, spongiosis, vescicle
4. mucosal breaks: erosion, ulceration, necrosis
5. solid lesions: macules (flat), papules (slightly raised), plaques (more raised), nodules
-dysphagia = painful mastication (difficulty handling food)
-ptyalism: hypersalivation
vesicular stomatides**
1. FMD: picornaviridae, apthovirus (ruminant, pig)
2. vesicular stomatitis: rhabdoviridae, vesiculovirus (ruminants, pigs, horses)
3. vesicular exanthema: caliciviridae, vesivirus (pigs)
4. swine vesicular disease: picornaviridae, enterovirus (pigs)
erosive & ulcerative stomatides
1. mucosal disease (cattle): BVDV
2. malignant catarrhal fever (cattle)
3. rinderpest (cattle)
4. peste des petits ruminants (sheep, goats)
5. bluetongue (sheep)
6. feline calicivirus (cats)
7. equine viral rhinotracheitis (horses)
-don't see erosive diseases much in dogs
bovine papular stomatitis
-parapoxvirus
-cattle & humans
-milker's nodules: on teats
orf
-parapoxvirus
-sheep & humans
-cantagious ecthyma
-contagious pustular dermatitis
-scabby mouth
necrotizing stomatitis
-cattle, sheep, pigs
-calf diptheria: necrotic pseudomembrane
-fusobacterium necrophorum
actinobacillus lignieresii (wooden tongue)
-cattle & occasionaly sheep
-yellow "sulphur" granules
-pyogranulomatous inflammation & fibrosis
-penetrating injuries of oral mucosa
-macrophages & neutrophils: pyogranulomatous
actinomycosis
-actinomyces bovis
-pyogranulomatous
-osteomylelitis: fibrosis & new bone formation
-similar inflamm. rxn as actinobacillus but affects bone
liver (functions)
1. carbohydrate metabolism: glycogen storage
2. fat metabolism: processing dietary fats to lipoprotein
3. protein metabolism: major site of protein synthesis (albumen, fibrinogen, some globulins, etc)
4. bile synthesis: abnormal bile metabolism is jaundice
5. storage: glycogen, iron, copper, fat soluble vitamins
6. detoxification: esp. nitrogenous compounds, hormones & drugs
liver (reaction to injury)
1. degenerative changes: eg. fattly change
2. necrosis
3. regeneration
4. fibrosis
5. inflammatoin
6. cholestasis
*eg. fasciola hepatica: necrosis, degenerative change, fibrosis, inflammation, regeneration
liver: degenerative change (vacuolar change)
-irregular clear spaces in cytoplasm
-hydropic change (excess water) or excess glycogen accumulation
-glycogen accumulation impt in: diabetes mellitius, steroid induced hepatopathy
-cells swell
-liver becomes paler
liver: degenerative change (fatty change)
-excess lipid is hepatic lipidosis or fatty liver
-liver enlarges & becomes yellow & greasy
-smooth lipid vacuoles in cytoplasm
-mechanism:
1. excessive fatty acids to liver: eg. starvation
2. excessive dietary intake of carbohydrates
3. decreased apoprotein synthesis
4. impaired secretion of lipoprotein from liver
liver: fatty change (diseases)
1. obesity
2. toxic & anoxic conditions: eg. excess alcohol
3. ketosis in cattle & pregnancy toxaemia in sheep
4. fat cow syndrome: over condition before calving & stop eating
5. equine hyperlipidaemia: eg. fat ponies
6. feline fatty liver syndrome
7. endocrine disorder: eg. diabetes mellitus
*NB: degenerative change is reversible
tension lipidosis (liver)
-discrete, pale areas oat liver margins
-common in older cattle
-close to attachment of ligament
-due to focal fatty change
-no pathological significance
liver: degenerative change (amyloidosis)
-pink, amorphous material deposited in space of Disse
-severe cases result in hepatic dysfunction or failure
-assoc. with chronic antigen stimulation
-serum protein (an acute phase protein) formed by liver
-in kidney: protein losing nephropathy
-in liver: hepatic failure
liver necrosis (zonal)
-centrilobar or periacinar
-midzonal necrosis
-periportal necrosis (usually ascending from gut)
-eg. bacterial or viral
liver necrosis
-basic rules apply: coagulative or liquefactive (nuclear disintegration, acidophilic cytoplasm)
-focal or random necrosis: sm. foci in any part of lobule
-zonal necrosis: restricted to particular parts of lobule
-massive necrosis: entire lobule
massive necrosis (liver)
-dissociation of liver cells: eg. leptospirosis
-cause usually unknown
-dog, pig
-collapse of liver
liver regeneration
-normal low level of liver cell proliferation
-massive potential for regeneration
-orderly repair of focal necrosis: as long as framework remains intacts
-repeated damage leads to distorted repair: complications with blood/bile flow (eg. cirrhosis)
-nodular hyperplasia in older animals
*NB: liver has massive ability for regeneration: remove 2/3 & rest will regenerate
liver inflammation
-hepatitis: inflammation of hepatic parenchyma
-cholangitis: inflammation of bile ducts
-cholangiohaptitis: both
-cholicystitis: inflammation of gall bladder
liver fibrosis
-response to necrosis & inflammation
-ito cells are source of collagen secreting cells
-ito cells located in space of Disse
-different pattern of fibrosis:
1. post necrotic scarring
2. bridgin fibrosis
3. diffuse, irregular fibrosis
liver pigments
1. bile: green discoloration
2. haemosiderosis: dark brown or black
3. lipofuschin: yellow-brown (age)
4. melanin: black or dark brown
haemoglobin derivatives
1. haemosiderin: excessive destruction of RBCs (free Fe)
2. haematin: parasitic infections
3. porphyrin: rare congenital disorders
4. bilirubin = haematoidin: excreted through liver, sites of haemorrhage
causes of jaundice
1. overproduction of bilirubin: intravascular haemolysis
2. hepatic cell failure: cirrhosis
3. choleostatis: intra or extrahepatic obstruction of bile flow
liver (aging)
-nodular hyperplasia: often incr. in fat (esp. dogs)
-pigmentation
-telangiectasis: dilation of BVs (blood filled channels)
-ceroid nodules with calcification
liver (post-mortem changes)
-autolysis is rapid
-bacteria from gut proliferates
-bile pigment diffuses to cause yellow discoloration
-becomes soft, pink & gas filled (lot of air spaces)
vascular diseases of liver
1. infarction
2. heart failure
3. portosystemic shunts
4. telangiectasis
5. venous thrombosis
liver infarction
-rare b/c dual supply: portal vein & hepatic artery
-torsion of individual lobes (eg. dogs & pigs)
-focal ischaemia in fascioliasis: stops short of infarction (no necrosis) but blood supply compromised
liver & heart failure
-right sided cardiac failure causes back pressure
-acute congestion:
1. enlarged
2. blood flows easily from cut surface
3. periacinar necrosis: dammed venous blood poorly oxygenated
-chronic congestion:
1. enlarged, nutmeg liver
2. periacinar necrosis, periportal fatty change
portosystemic shungs & liver
-vascular channels that allow blood to bypass liver
-congenital or aquired (see cirrhosis)
-failure to detoxify ammonia: CNS effects
portosystemic shunts (congenital)
-most common in cats & dogs
-persistence of ductus venosus
-portal vein directly to caudal vena cava
-portal vein to azygos vein
-small liver
-unperfused BVs in portal triad
telangiectasis
-dilation of sinusoids
-dark blue foci in liver
-common in adult cattle & cats
-can rupture in cats
liver: venous thrombosis
1. posterior vena cavaa (across top of lvier) thrombosis:
-complication of hepatic abcessation
-nutmeg liver: interferes with outflow
2. portal vein thrombosis
-rare
-acquired portosystemic shunts
hepatic displacement
-congenital diaphragmantic hernia: liver pushed thru to pericardial space
-traumatic diaphragmatic defects: really a hernia, eg. from RTA
hepatic trauma
-RTA, kick, fall
-fissures on liver surface
-abdominal haemorrhage
viral infections of liver
1. adenovirus (type1): infectious canine hepatitis (multiplies in lymphoid system then to liver)
2. herpesvirus: many species, Pacheco's disease (parrots)
3. coronavirus: infectious peritonitis (cats) --> pyogranulmatous, infects macrophages
4. circovirus: haemorrhageic disease (rabbits)
bacterial diseases of liver (general)
-bacterial hepatitis following bacteraemia
-common in all species
-focal distribution
-routes:
1. generalized bacteraemis: hepatic artery
2. umbilical vein (unique to liver)
3. gastro-enteric infection: portal vein
4. direct extension: via reticulum
5. pancreatic/enteric: vial biliary system
bacterial diseasees of liver (examples)
1. Black disease (sheep/cattle): Clostridium novyi (anaerobic) & fluke (fluke causes local necrosis & C. novyi moves in)
2. leptospirosis (dog/man/rat): L. icterohaemorrhagiae
3. bacillary haemoglobinuria (cattle): C. haemolyticum/fluke
4. Tyzzer's disease (mice): bacillus piliformis
5. tuberculosis (all species): mycobacterium spp (taken up by macrophages --> granulomatous rxn)
6. E. coli hepatitis (broiler chickens)
bacterial diseases of liver (liver abcesses in cattle)
-common in barley beef cattle: top end of market
-rumenitis to hepatitis via portal vein
-fusobacterium, mucor spp, A. pyogenes
-multiple abcesses
-liquefactive necrosis
-fibrous scars: some repair
-caudal vena caval thrombosis
protozoa of liver
1. toxopasmosis (cat/dog): toxoplasma gondii
-areas of focal necrosis
-sexual stage in cats
2. coccidiosis (rabbit): eimeria stediae
3. black head (turkeys): Histomonas
nematodes of liver
1. capillaria hepatica (dogs): adults & eggs (obscure)
2. ascaris suum (pigs): larvae --> 'milk spots'
3. strongylus spp (horses): larvae
cestodes of liver
1. cysticercus tenuicollis: sheep
-from intestine via portal circulation --> from inside to out --> encysts
-immature cysts that are stopped by immune system become calcified
2. taenia hydatigena: dogs
3. echinococcus granulosus: dog
4. hydatid cysts: sheep, cattle, pigs, man
3. echin
trematodes of liver
1. fasciola hepatica (sheep/cattle): liver fluke
-grossly enlarged hepatic lymph nodes
-fluke attempts to reach bile ducts: from outside to inside
2. dicrocoelium dendriticum (sheep): tea leaf fluke ('enslaver' parasite with ant IMH)
liver fluke (pathogensis)
-metacercaria penetrates wall of intestine
-crosses peritoneal cavity
-creates tracts of necrotic liver parenchyma
-tracts heal by fibrosis
-flukes enter bile duct
-chronic cholangitis, ectasis, stenosis (dilation)
-acute: lots of flukes entering at once
-leaves behind track of haemorrhage, eosinophils & fibrosis
-if strike a BV, my compromise blood flow to area (indirect)
-tends to 1st to left lobe & then to caudate process
-cattle: chronic cholangitis calcifies --> 'pipe stem' lesions
-liver may alter shape to compensate: left lobe/caudate process atrophy & right lobe hypertrophy
toxic liver disease
-common site of toxic injury
-2 main factors:
1. portal vein drains toxins from intestine
2. hepatocytes remove toxins
-predictive hepatotoxins: predictable haptic injury (eg. alcohol)
-idosyncratic: unpredictable (eg. penicillin)
hepatic biotransformation
-hepatic enzymes make endogenous & exogenous substrates suitable for elimination
-lipid soluble compounds are made water soluble
-biotransformations can create toxic metabolites
-hapatocytes vary in their enzyme components
common hepatic poisons
1. ragwort (cattle/horses): pyrroloziden alkaloid
2. blue-green algae (dogs/cattle/sheep): toxic polypeptides
3. mycotoxins (all): fungal metabolites (eg. spoiled feed)
4. copper (sheep)
copper poisoning (liver)
-esp. sheep
-sequestration of copper in liver (accumulates)
-delayed biliary excretion of copper
-sudden release of copper: more hepatocytes die than can be replaced
-haemolysis (intravascular), severe anaemia
-periacinar necrosis with massive release of copper
tumors of liver
1. congenital cysts
2. hepatocellular tumors: adenoma, carcinoma
3. cholangiocellular tumores (bile duct): cystadenomas, bile duct carcinomas
4***. secondary tumors (more common than primary):
-lymphoid tumors: eg. lymphosarcoma
-haemangiosarcoma (from spleen)
-pancreatic carcinoma
cirrhosis
-end stage liver
-whole liver involved
-necrosis at some stage
-nodular regeneration (attempt at healing)
-diffuse fibrosis: disorganization
-yellow/orange color & very firm