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407 Cards in this Set

  • Front
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Cerebellar Abiotrophy
Atrophy of the cerebellum after it has reached its full size
Copper deficiency
In Sheep
"Swayback"
Lesions of Copper deficiency
necrosis of the white matter
hydranencephaly
axonal degeneration-enzootic ataxia
Ezootic Ataxia
Axonal degeneration that results from Copper Deficiency
Hypomyelinogenesis
Failure of myelin to develop
affects sheep, pig, dogs
Signs of hypomyelinogenesis
Tremors
Shaking
Abnormal wool
Causes of hypomyelinogenesis
Inherited-pigs & dogs
Border disease-sheep
Border disease
Causes "hairy shakers"
abnormal wool=looks like hair
w/ shaking
Causing hypomyelinogenesis & hydranencephaly
Spina Bifida
Failure of the spine to completely close during development, allowing the meninges and/or spinal cord to protrude
Meningomyelocele
Meninges & Spinal Cord protrude through opening in spine
Meningocele
meninges protrude through opening in spine
Signs of Edema in the nervous system
swelling of the brain, flattening the gyri, forcing cerebellum into foramen magnum
2 Sources of edema in the nervous system
Vasogenic-intercellular
Cytotoxic-intracellular
Vasogenic edema of the nervous system
usually focal
-seen with neoplasia, inflammation & trauma
Cytotoxic edema of the nervous system
from toxins=salt & lead
cause neuronal necrosis
Also from hepatoencephalopathy (liver disease)
2 Causes of infarcts in the nervous system
Feline ischemic encephalopathey
Emboli
Feline ischemic encephalopathy
Idiopathic disease that causes necrosis in the cerebrum
Causes siezures, ataxia, blindness & behavor changes
2 sources of emboli in the nervous system
Bacterial
fibrocartilaginous
Bacterial emboli in the nervous system
With systemic infection=multifocal, hemorrhagic infarcts & encephalitis
Hemophilus somnus in cattle
Fibrcartilagenous emboli in the nervous system
An emboli of disk material that lodges in the spinal cord causing infarction
in pigs & dogs
Signs of a fibrocartilagenous emboli in the nervous system
discolored/ swollen/ hemorrhagic spinal cord
Sudden onset posterior paralysis
Hemorrhage & contusion in the nervous system
Usually caused by trauma
also seen with other pathologic events, necrosis, infarction, & iatrogenic
Types of degenerative lesions of axons
Compression
Toxins
Degenerative myelopathy
Compression degenerative lesions of axons
Herniation of intervertebral disk
Cervical vertebral stenotic myelopathy
Herniation of intervertebral disk
Most common in long backed (chondrodystrophoid) breeds
Causes sudden posterior paralysis/paresis and pain
Compression of axons
Degeneration of neurons in white matter & loss of myelin
Microscopically, axons are lost & myelin sheath is swollen, leaving vacuoles of different sizes.
Hydromyelia
dilation of central canal of spinal cord
causes pressure atrophy of surrounding cord
Cervical vertebral stenotic myelopathy
"wobbler syndrome"-horses
caused by malformed cervical vertebrae=stenosis of spinal canal
or damaged articular surfaces=increased movement of vertebrae
Toxins that cause Degenerative lesions of axons
Organophosphates
Copper deficiency
Organophosphates role in creating degenerative lesions of axons
exposure causes a delayed neurotoxicity, causing degeneration of distal axons in both central & peripheral nervous systems
Signs of Organophosphate toxicity
Ataxia
weakness
proprioceptive deficit
paralysis
Degenerative myelopathy
no known cause, no gross lesions
affects young horses & old dogs
leads to progressive ataxia in all 4 limbs
Wallerian degeneration of entire spinal cord
Lesions of Necrosis in the nervous system
Usually no gross lesions
microscopically, neurons are red (instead of blue)
Edema often seen
Polioencephalomalacia
=necrosis of the cerebral cortical gray matter
gray matter becomes soft to touch, & visibily yellow
Causes of Polioencephalomalacia
Thiamine deficiency
Salt poisoning
Lead toxicity
Hypoxia/ischemia
Neonatal maladjustment syndrome
Leukoencephalomalacia
Clostridium perfringes type D
Thiamine deficiency
Usually a problem in cattle, who produce Thiamine in the rumen, but can be destroyed before absorption by an alteration of rumenal flora
Causes of Thiamine deficiency
Altered diet
-high concentrate diets
-high molases diets
-high sulfate diets
all cause an alter rumenal flora
Signs of Thiamine deficiency in cattle
blindness
paresis
recumbency
teeth grinding
opisthotonus
extensor rigidity
Salt poisoning
Presents similar to Thiamine deficiency, but more commonly in pigs
Pathogenesis of Salt poisoning
Sudden rehydration after prolonged dehydration, causes brain edema & neuronal necrosis-lead to polioencephalomalacia
Lead toxicity
Usually seen in ruminants from lick lead paint or batteries
Signs of lead toxicity
excitable/hyperactive
bellowing
seizures
blindness
staggering
recumbent w/ tremors
Hypoxia/ischemia of the nervous system
cerebral cortex, hippocampus & Purkinje fibers extra sensitive
can occur with prolonged seizures & anasthesia
-can lead to polioencephalomalacia
Neonatal maladjustment syndrome
occurs in foals following a dystocia, in which they suffered hypoxia/ischemia
they wander, have seizures and don't suckle
Leukoencephalomalacia
necrosis of the white matter
occurs in horses after ingesting moldy corn, infected w/ Fusarium fungus
Lesions of Leukoencephalomalacia
Thickened, yellow, edematous white matter
Signs of Polioencephalomalacia
Staggering
weakness
circling
depression
head pressing
Seizures/excitability, then death (only takes a few hours)
Role of Clostridium perfringens type D infection necrosis of the nervous system
Seen after an animal recovers from intitial enteritis, because bacteria produce toxins that reach & affect the brain
lesions of Clostridium perfringens type D infection
Neuronal necrosis & hemorrhage of the basal ganglia, cerebellar peduncle & internal capsule
Perivascular cuffing
a general response to injury in the CNS
Inflammatory cells (usually lymphs)
Common bacterial infection of the nervous system
Listeria
Hemophilus somnus
Meningitis
usually caused by bacterial infections
=inflammation of the leptomeninges, pia and arachnoid
-seen as predominantly neutrophils
may lead to fibrosis purulent meninges
Menigoencephalitis
A meningitis that extends down into neuropil
Neuropil
The fibers that make up nervous tissue
-the pink background of a normal section
Abscesses in the nervous systems caused by bacteria
generally w/in the epidural, subdural or neutropil as focal abscesses
Choroiditis
localized inflammation of the choroid
may cause exudate to be seen in the ventricles
Ependymitis
localized inflammation of the ependyma
may cause exudate to be seen in the ventricles
Sources of bacterial infection of the nervous system
usually hemotogenous
also for neighboring structures=middle ear
or penetrating wounds
Listeria
Important pathogen in cattle
enters through mouth following trauma, migrates up cranial nerves
Produces multifocal purulent encephalitis & microabscesses in brainstem
Signs of listeria infection
circling
depressed attitude
head pressing
7th cranial nerve paralysis=drooping of eyelid, lip or ear on one side
Hemophilus somnus infection
a important infection of young cattle that produces TEME
Lesions of Hemophilus somnus infection
vasculitis w/ thrombosis of cerebral vessels
Creates gross multifocal hemorrhages
Arthritis & pneumonia also common since commensal of respiratory tract that can become systemic
7 Congenital defects of nervous system
hydrocephalus
hydranencephaly
cerebellar hypoplasia
cerebellar abiotrophy
copper deficiency
hypomyelinogenesis
spina bifida
(3)Circulatory Disturbances of the nervous system
edema
infarcts
emboli
(3) degenerative lesions of neurons
lysosomal storage diseases
transmissible spongiform
encephalopathy chromatolysis
(3) degenerative lesions of axons
compression
toxins
degenerative myelopathy
(3)causes of necrosis in the nervous system
polioencephalomalacia
hypoxia/Ischemia
neonatal maladjustment syndrome
leukoenaphalomalacia
clostridium perfringens type D
(4) causes of inflammation of the nervous system
bacteria
viruses
fungi
parasites
(6) neoplasms of the nervous system
meningioma
glial cell tumors
choraid plexus tumors
ependymoma
neuronal cell tumors
schwann cell tumors
hydrocephlus
dilation of ventricles
caused by a blockage
CSF builds up
causes pressure atrophy of
overlying nervous tissue
causes of hydrocephalus
aquined
primary neoplasm
secondary inflammation
congenital
idiophatic
hydranenophaly
dilation of ventricles
caused by a loss of overlying
tissue
(usually a cavity other than ventricles that fills w/ CSF)
causes of hydranencephaly
blue tongue viruses-sheep
border disease-sheep
BVD-cattle
cerebellar hypoplasia
cerebellum fails to develop to normal size
causesof cerebellar hypoplasia
BVD-cattle
Panleukopenia- cats
signs of cerebellar hypoplasia
lysosomal storage diseases of nervous system
caused by deficiency of an enzymes in lysozomes
-usually an autosomal recessive condition in dogs & cats
can be acquired by toxins that inhibit certain anzymes
characterized by which materials accomulate
signs of a lysozomal storage disease
ataxia \ shortly
incoordination after
tremors / birth

lead to death w/ in months
no gross lesions but
neurons appear foamy or granular microscopirally
transmissible spongiform enaphalopathy
caused by priors
-affect young animals
no gross lesions
but many hales(vacuoles)microscopically in neurons + neurophil
scrapie-sheep
BSE-cattle
signs of transmissible spongiform encephalopathy
no clinical signs before 2 yrs. old
-long incubation period
behavior changes
ataxia
pruritis(sheep)
microscopically=vacuales in neurons + neuropil
chromatolysis
occurs when a neurons is damaged or in axonal degeneration
dispersion of nissl substance.make cytoplasm look like ground glass
Lesions of Viral infections of the nervous system
No gross lesions
perivascular cuffing
Chromatolysis
necrosis
Perivascular cuffing
inflammation around blood vessels
Causes of viral infections of the nervous system
Rabies, Pseudorabies
Equine viral encephalitis
Retrovirus
Canine distemper
Equine herpes virus 1
Rabies infection
Caused by a Rhabdovirus
produces Negri bodies
has various clinical signs of neurologic disease
Death occurs w/in 10 day of clinical signs
Negri bodies
Eosinophilic intracytoplasmic accumulations of virus in neurons
A sign of Rabies infection
Pseudorabies
herpes infection of pigs
Severity of disease depends on age of animal; young=severe neurologic disease, old=mild respiratory disease
Highly contagious
Pseudorabies in other animals
Intense purtitis
and usually fatal
Signs of Pseudorabies infection
No gross lesions
Intranuclear viral inclusion bodies
Equine Viral encephalitis
caused by a arbovirus
transmitted by mosquitoes
Causes blindness & circling
Paralysis & death in 1-2 days
Diseases caused by Retrovirus infection
Caprine arthritis encephalitis
Visna in sheep
Lesions of Retrovirus infection
demyelination in spinal cord
encephalomyelitis in kids
arthritis & pneumonia in adults
lead to paralysis & ataxia
Canine distemper
caused by morbillivirus
Causes myoclonus (repetitive contraction) of muscles of mastication
"Myoclonus"
Repetitive muscle contraction
signs Canine distemper
Affects respiratory, intestinal tracts & nervous system
Intranuclear & intracytoplasmic inclusions
Equine Herpes virus 1
Usually causes abrotion, but can also cause neurologic disease=vasculitis & hemorrhage of the spinal cord & brain
Signs of Equine Herpes virus 1
Ataxia, paresis- may progress to recumbency
Fungal infections infecting the nervous system
produce granulomatous/ pyogranulomatous inflammation
Cryptococcus
Cryptococcus infection
most common in cats
enter through nasal mucosa & progress up to brain
Produce meningitis/ meningoencephalitis
Diagnosis of Viral infection
Immunohistochemistry
Viral PCR
Parasites that affect the nervous system
Multifocal inflammation & necrosis in gray & white matter
Equine Protozal myelitis
Parelaphostrongylus tenuis
Equine Protozoal myelitis
Caused by Sarcocystis neurona
No gross lesions
Paralysis, paresis & ataxia
Parelaphostrongylus tenuis
Affects sheep & llamas
caused by a nematode from deer
Infection limited to spinal cord-causing Paralysis, paresis & ataxia
Idiopathic diseases of the nervous system
Granulomatous meningoencephalitis
Cauda equina neuritis
Granulomatous meningoencephalitis
affects dogs
no gross lesions
mainly affects white matter
Cauda equina neuritis
Granulomatous inflammation w/ fibrosis of the cauda equina nerves in EQ
causing incontinence, perineal anesthesia & tail paralysis
6 Neoplasias of the nervous system
Glial cell tumors
Choroid plexus tumors
Ependymoma
Neuronal cell tumor
Schwann cell tumor
Glial cell tumors
Astrocytoma
oliogodendroglial tumor
microglial tumor
Astrocytoma
Most common Glial cell tumor
Usually in short-faced breeds
tan, gray or white masses in cerebral cortex
Choroid plexus tumors
Vascular, red & friable grossly
usually in the 4th ventricle
adenomas & adenocarcinomas
Meningioma
Most common tumor in the CNS
Ventral in dogs
Dorsal in cats
white/gray fibrous mass on surface of brain
Ependymoma
Rare
inside ventricles (like Choroid tumors) but white/gray/tan
Neuronal cell tumors
Rare
usually in peripheral nervous system
firm, white nodules= ganglioneuroma
Schwann cell tumor
"Peripheral Nerve Sheath Tumor"
Uncommon
usually in dog, usually in peripheral nervous system
in skin & brachial plexus= unilateral limb paralysis
Characteristic of Bacterial infection of nervous system
Neutrophils
Characteristic of Viral infection of nervous system
Lymphs, plasma cells
Perivascular cuffing
Characteristic of Parasite infection of nervous system
Eosinophils
Fusobacterium necrophorum in the oral cavity
Gram - bacteria
affects young cattle
causes ulceration & caseous proliferations in mouth & larnyx
introduced by trauma
Actinobacillus/actinomyces in the oral cavity
Cause wooden tongue & lumpy jaw-firm, fibrous, nodular proliferations of jaw & tongue
Gingival hyperplasia
Proliferation of the gingiva usually caused by chronic periodontal disease in dogs
6 Neoplasias of the oral cavity
Melanoma
Squamous cell carcinoma
fibrosarcoma
epulis
papilloma
Tooth germ tumors
Melanoma in the oral cavity
Tumor of melanocytes, only occur in the oral cavities of dogs
usually malignant
Squamous cell carcinoma of the oral cavity
malignant tumor of squamous epithelium occurs in oral cavity of cat & dog
common on the cats tongue
Fibrosarcoma in the oral cavity
tumor of fibroblasts in the oral cavity in dogs occur as malignant solitary nodules
Epulis
benign tumor of dog gingiva
arises from the peridontal ligament
resembles gingival hyperplasia grossly
Papilloma in the oral cavity
a wart caused by papilloma virus usually seen on skin
also occur in oral cavity of dogs & rumen of cattle
usually clear on own
Tooth germ tumors
Ameloblastoma
odontoma
more common in young animals
generally benign
Ameloblastoma
tumor of enamel-producing cells (tumor cells don't make enamel though)
can be locally invasive to the underlying bone
Odontoma
Benign tumor
look like fully-formed/ misshapen teeth
Disturbances of the teeth
Enamel hypoplasia
Excessive tartar
Enamel hypoplasia
Enamel fails to form on teeth
leaves weaker dentin exposed so teeth chip & break easily
Causes of enamel hypoplasia
Canine distemper
too much flourine
Lesions of salivary glands
Ranula
Mucocele
Sialoadenitis
Salivary gland adenocarcinoma
Mucocele
a distended salivary gland duct caused by an obstruction, fills with mucous
Sialoadenitis
inflammation of the salivary gland
RATS
Salivary gland adenocarcinoma
Solitary nodules in submandibular region
occur in dogs/cats & will metastasize to local LN & lung
Must differentiate from thyroid & LN tumors
Ulcerative lesions of the esophagus
BVD
Malignant catarrhal fever
Choke
Choke
in the horse of dry, course feed
produce annular ulcers in the esophagus, heal by fibrosis & constriction which predispose to reoccurrence
Proliferative lesions of the esophagus
white/yellow caseous material, forms plaques in esophagus
Causes of proliferative lesions of the esophagus
Avain pox
Hypovitaminosis A
Candida
Trichomonas
Avian Pox
white/yellow caseous plaques in oral cavity, crop & esophagus
Hypovitaminosis A
Causes keratinization of the esophagus & internal glands & other places lined with epithelium
Candida (Thrush)
yeast infection in immunocompromised animals
Trichomonas
Protozoal infection in the crop & esophagus
usually pigeons
Physical distrubances of the esophagus
Megaesophagus
Megaesophagus
dilation of the esophagus
can be congenital-persistant right aortic arch
or secondary-myasthenia gravis
Edematous lesions of the Stomach/Abomasum
usually seen in animals with hypoproteinemia
Edema disease
occurs in swine w/ E. coli infection
Rugal folds of stomach appear pronouncedly swollen
Causes of ulcerative lesions of the stomach/abomasum
Gasterophilus (bot) larvae
Stress
Steroids/NSAIDs
Gasterophilus larvae
Stomach bots
cause no clinical disease
ulcerate along the margo plicatus
Causes of hemorrhage in the stomach/abomasum
Heavy metals
Uremia
BVD
lesions much redder than normal post-mortem congestion
may even be black/brown from digested blood
Heavy metals affect of the stomach/abomasum
Arsenic & Mercury
Anticoagulant poisoning
cause ulceration w/ hemorrhage in abomasum & intestines
Lesions of Uremia in the stomach/abomasum
Uremia damages blood vessels leading to ulceration & hemorrhage
Physical disturbances of the stomach/abomasum
Bloat
Gastric destention w/ volvulus
Displaced abomasum
Rupture
Phytobezoars
trichobezoars
Bloat
Gas distention of the stomach
usually in horses eating too much grain
leads to CV failure, shock, death & stomach rupture
Gastric distention w/ volvulus
usually deep-chested dogs
gas distention interfers w/ venous return, causing death w/in hours
Vovulus
rotation of stomach around esophageal junction
(not a torsion)
Displaced abomasum
movement of the abomasum in cattle, usually @ or after parturition
Stomach rupture
usually in horses w/ intestinal blockage or gas distention
Phytobezoars
Balls of plant material in the stomach
usually incidental until block pylorus
Trichobezoars
Balls of hair in the stomach
usually incidental until block pylorus
7 Causes of Proliferative lesions of the stomach/abomasum
Hyperplasia
Gastric carcinoma
Squamous cell carcinoma
Lymphoma
Leiomyoma
Eosinophilic gastroenteritis
Draschia megastoma
Hyperplasia of the stomach/abomasum
Most common cause is Ostertagia in cattle producing cobblestone appearance w/ small raised, white plaques
But many other parasites can cause hyperplasia
Gastric carcinoma
really an adenocarcinoma
highly malignant tumor of dogs
thickened fibrosis of stomach wall, may ulcerate
metastasis to abdomen
Squamous cell carcinoma in stomach
highly malignant tumor in horses' stomach
occur as ulcerated fibrous masses in the nonglandular region
Lymphoma in the stomach
occurs in dogs & cats
homogenous smooth tan mass in stomach wall w/o fibrosis
Leiomyoma of the stomach
benign tumor of smooth muscle
=discrete tan nodule in the wall beneath the mucosa
Eosinophilic gastroenteritis
Grossly looks like a carcinoma
but filled w/ eosinophils & fibrosis
Draschia megastoma
a nematode of horses
burrows into the glandular stomach causing nodules w/ a central pore
no clinical significance
Causes of ulcerative lesions in the rumen
Bloat
Bloat in the rumen
usually caused by grain overload or legumes
production of lactic acid damages the rumen mucosa
Prone to secondary infection w/ fungi or fusobacterium
Bloat line
Line along the esophageal mucosa
above the line is congested, below is pale-b/c negative pressure in thoracic cavity & bloat blood can't drain down the esophagus
Proliferative lesion of the rumen
Papilloma
Papilloma of the rumen
white, wart-like growths caused by papilloma virus
4 Causes of ulcerative lesions in the small intestines
SALMONELLA
BVD
Amoeba
Ulcerative enteritis
Salmonella
affects the large intestines of horses & pigs
Small intestines of cattle
Produces hemorrhage, ulcers & fibrosis
BVD in the small intestines
produces eliptical ulcers over the Peyer's patches
(nearly diagnostic for disease)
Amoeba in the small intestines
Cause ulcerative enteritis in reptiles
Ulcerative enteritis
if young poultry=clostridium colinum infection
discrete, deep yellow ulcers & multifocal yellow spots on liver
Causes of fibrosis in the small intestines
SALMONELLA
Necrotic enteritis
Lesions can be as sheets of fibrosis
Necrotic enteritis
in Chickens
caused by Clostridium perfringens
produces diffuse necrosis w/fibronecrotic pseudomembrane
Causes of Hemorrhage in the small intestines
DIC
Heavy metals
Parvovirus
Hookworms
Clostridium perfringens
Coccidia
DIC
Disseminated Intravascular Coagulation
in dogs & cats, clotting factors are exhausted, causing diffuse bleeding through the body including intestines
Heavy metal poisoning
Arsenic & mercury poisoning in ruminants=hemorrhage in small intestines
Parvovirus
Viral infection of dogs & cats
virus destroys crypt cells causing ulceration & hemorrhage in dogs
Hookworms
nematode parasite of dogs
worms dig into S.I. & suck out blood, leading to hemorrhage
Clostridium perfringens (A & C)
bacterial infection causing diffuse intestinal hemorrhage in young (<2 weeks old) LA
Coccidia
with sever infections can produce acute hemorrhagic enteritis in cattle & birds
chronic infections in sheep produces raised plaques/ nodules
7 causes of Proliferative lesions in the small intestines
Lawsonia intracellularis
granulomatous enteritis
mycobacterium avium
Coccida
chronic obstruction
Hemomelasma ilei
idiopathic muscular hypertrophy
Lawsonia intracellularis
infection in pigs
causes extreme thickening of intestinal mucosa, necrosis & hemorrhage
Also occurs in horses & dogs
Granulomatus enteritis
horses intestinal mucosa infiltrated w/ macrophages
but cause is idiopathic
Mycobacterium avium
infects birds (sometimes mammals)
intestines are diffusely thickened by granulomatus inflammation
Idiopathic muscular hypertrophy
occurs in distal ileum & esophagus of horses
usually no clinical disease unless the ileum becomes obstructed
Chronic obstruction of intestines
can cause the muscularis to thicken @ site of obstruction
Hemomelasma ilei
occurs in the horse
red/brown plaques on serosa
idiopathic cause, no clinical disease
3 Neoplasms of the small intestines
Lymphosarcoma
Leiomyoma/leiosacroma
Adenocarcinoma
Lymphosarcoma in the small intestines
Causes segmental thickening of the intestinal walls
homogenous tan nodules, may be w/ hemorrhage & necrosis
Lieomyoma in small intestines
Tumor of smooth muscle producing smooth tan nodules in the wall of intestines
Lieosacroma
Same appearance as lieomyoma
not very malignant & little metastasis potential
Adenocarcinoma of small intestines
Tumor occurs as abundant fibrous tissue that forms a constricting annular band
Very malignant & will metastasize
5 Physical disturbances of the small intestines
Torsion/volvulus
Intussusception
Strangulation
Hernia
All produce diffuse congestion, hemorrhage & edema
Torsion of the small intestines
Twisting of the intestines about itself
Volvulus
twist of the intestines about the mesenteric axis
seen commonly in horses
blood gets in, but then can't get out
Strangulation of the small intestines
When the intestines become trapped in a band of concective tissue
Usually caused by lipoma hanging from mesentaries by a fibrous band in horses
Hernia
Entrapment of intestines in inguinal rings, open umbilicus or diaphragm
7 Causes of excess fluid in a (otherwise) normal intestines
E. coli
Rotavirus / coronavirus
Cryptosporidia
Clostridium perfrigens D
Lymphangiectasia
inflammatory bowel disease
Panleukopenia
None have gross lesions
Significance of E. coli infections
can cause an excess of fluid in intestines in young pigs, foals & ruminants
Rotavirus/coronavirus
infections in young pigs & ruminants, that destroys villi epithelial cells
Causes malabsorption & diarrhea
Cryptosporidia
Protozoal infection in young pigs & ruminants
Attach to microvillous of intestinal epithelium cells
Clostridium perfringens type D
Infection in sheep from switching from poor quality to high quality feed-allows bacterial overgrowth
produce exotoxin= enterotoxemia
Lymphangiectasia
idiopathic cause
dilation of lacteals of intestinal villi-causes malabsorption
Inflammatory Bowel Disease
allergic enteritis in dogs & cats
Panleukopenia
caused by a parvovirus in cats
causes hypoplasia of cells in bone marrow & necrosis of intestinal crypts
3 Causes of ulceration in the large intestines
Swine dysentery
Ulcerative colitis
Shigella
Swine dysentery
disease in pigs caused by Brachyspira hyodysenteriae
Produces ulcerative & fibrinous colitis
Ulcerative colitis
idiopathic
Ulcers & macrophages in the mucosa
Seen in Boxers
Shigella
Bacterial infection of primates causes ulcerative (& sometimes hemorrhagic) colitis
6 Causes of Fibrinous/Necrotic/ Fibrinonecrotic colitis
Salmonella
Yersinia Pseudotuberculosis
Histomonas meleagridis
Trichuris
Strongyles
antibiotics/NSAIDs
Salmonella in Large intestines
usually affects horses
can cause ulcers/ hemorrhage / fibrinous / fibrinonecrotic
Yersinia Pseudotuberculosis
mainly affects primates & rodents but can occur in ruminants
causes multifocal fibrinonecrotic colitis
Histomonas meleagridis
protozoal infection of turkeys
causes caseous necrotic cores in the ceca that plug ceca
Trichuris
whipworms-most infections don't cause disease
heavy infections cause fibrinous colitis in dogs & pigs
Strongyles, oral antibiotics & NSAIDs affect on large intestines
cause fibrinous colitis in right, dorsal colon of horses
4 Causes of hemorrhagic colitis
Colitis X
Salmonella
DIC
Anticoagulant toxicosis
Colitis X
a disease of horses, probably caused by overgrowth of clostridium
Produces hemorrhage in the colon wall, more so than the lumen
2 Causes of proliferative colitis
Johne's Disease
Neoplasia
Johne's Disease
caused by Mycobacterium avium subspecies paratuberculosis in ruminants
produces a cerebellar fold (thickening) pattern in mucosa due to granulomatous inflammation
Neoplasms of the Large intestines
Lymphoma
Adenocarcinoma
Leiomyoma
4 Physcial disturbances of the large intestines
Impaction
Dilation
Atresia Coli/ani
Torsion
Intussusception
Intussusception of large intestines
usually the cecum telescoping into the colon
Impaction of the large intestines
occurs in the large intestines of horses caused by enteroliths (mineralized concretions)-may lead to rupture
Atresia coli/ani
congenital defects seen in cattle
the colon ends as blind sac, that doesn't connect to outside
or no anus forms
Dilation of the large intestines
megacolon
can occur secondarily to spinal disc disease in dogs
Potomac horse fever
Rickettsia infection on horses
insect vector
patchy congestion of colon mucosa but no damage, & the colon fills w/ watery fluid
Causes of Ascites
Chronic liver disease
Heart failure
Ascites
the accumulation of clear, yellow fluid in the abdomen
-leaks from blood vessels
Causes of peritoneal edema
E. coli
Hemoperitoneum
Edema disease
E. coli infection in swine
- exotoxins cause edema of subcutis, stomach + mesentery
3 causes of fibrinous peritoneum
Traumatic reticuloperitonitis
Ruptuned bladder
Feline infectious peritonitis
Traumatic reticuloperitonitis
" hardware disease "
wire penetrates reticulum
results in filrinous pericarditis + peritonitis
FIP
Feline infectious peritonitis
Caused by corona virus
-high protein fluid accumulates in body cavities w/strands of fibrin
-small white plaques form on mesentry
-granulomas form on organs + around blood vessels
Fat necrosis
becomes mineralized
appears firm, chalky, yellow-brown plaques / nodules
5 causes of fat necrosis
vitamin E deficiency
Pancreatitis
Fescue toxicosis
lipomas
Idiopathic
Vitamin E deficiency
when occur in cats causes fat necrosis in subcutis, amentum + mesentry
- common w/ all fish diets
How Pancreatitis causes fat necrosis
in dog + cat
leakage of enzymes from pancreas
causes necrosis of mesentric fat around the pancreas
3 causes of proliferative diseases of peritoneum
chronic peritonitis
mesothelioma
FIP
Mesothelioma
neoplasm of mesothelial cells
- usually congenital in calves or aquired in old dogs
produces multiple white nodules / plaques in abdomen, thorax or pericardium
Pancreatic hypoplasia
exocrine pancreas doesn't develop
endocrine part is normal
- in young German Shepherds
- have a voracious appetite
- large voluminous, foul-smelling feces b/c no digestive enzymes but have insulin production
Acute pancreatitis
idiopathic cause
leads to necrosis + hemorrage of the pancreas fibrin also deposits
Usually occurs in dogs,
frequently in those who like to eat out of the trash
3 causes of nodular / proliferative lesions of pancreas
Chronic pancreatitis
Neoplasia
Hyperplasia
Chronic pancreatitis
repeated pancreatitis causes healing by scarring
makes pancreas pale tan, firm + nodular
Neoplasms of the pancreas
can affect exocrine + endocrine tissues
Adenomas - usually single yellow / white nodule
Edenocarcinoma - large + infiltrative
Hyperplasia of pancreas
incidental in dogs
small tan- white nodules of exocrines tissue
Significance of tan or brown liver
modurate amounts of fat or glycogen deposits
Diffuse = pathologic
focal / multifocal = physiologic
Significance of yellow liver
large amounts of fat accumulation
usually because softer
Sinificance of green liver
excess bile accumulation
- blockage of bile ducts
- damage hepatic cells
- too much coming in from breakdown of RBCs
Significance of red or red-brown livers
congestives
- normal acurence @ necropsy
5 causes of lobular / reticular pattern in liver
passive congestion
anemia
lipid
hepatotoxins
cholongitis
Significance of lobular / reticular pattern in liver
usually non-infecttious causes
disease process affecting specific areas of lobule makes lobules grassly visible
Passive congestion in lobular pattern of liver change
the most common cause
- usually b/c of heart failure
- also becomes congested = red / red - brown
Anemia in lobular pattern of liver change
causes hypoxia of centrilobular cells
- causing lobular pattern
lipid in lobular pattern of liver change
may accumulate diffusely or in centrilobular are alone
Hepatotoxins in lobular pattern of liver change
toxins can damage centrilobular cells
- makes then necrotic or accumulate lipids
Drugs
Toxic plants
Chemicals
Cholangitis in lobular pattern of liver change
inflammation of bile ducts
(uncommom, w/ bacterial infection)
Sources of insulin for animals
Human insulin-100 units/ml
Porcine insulin-40 units/ml
Veterinary insulin
Porcine
40 units/ml
special (different) syringes, than human insulin
Differences in short-acting insulin preparations
can be given IV or SC
Differences in intermediate-acting insulin preparations
suspensions given SC once daily or bid
Differences in long-acting insulin preparations
Suspensions given SC once daily
Larger particles slows absorption
protein-binding slows elimination
Treatment for hyperglycemia
From overdose of insulin or other cause
can given IV dextrose or Glucagon
Glucagon
Used to treat hypoglycemia and shock
rapid onset & short duration
Signs of insulin reaction
Hypoglycemia
rapid onset of weakness, confusion, convulsions w/ moist skin & rapid shallow breathing
Signs of a diabetic coma
Hyperglycemia
Gradual onset of drowsiness, "dim vision" w/ dry, flush skin & acetone breath, thirst, rapid pulse
Significance of hormones of the adrenal cortex
Glucocorticoids & mineralocorticoids important in carbohydrate metabolism
Addison's disease
Hypoactive adrenal cortex
Cushing's disease
Hyperactive adrenal cortex
Uses of glucocorticoids
to replace from hypoactive adrenal gland
also as antiinflammatory (membrane stabilizer)- ↓ synthesis & release of inflammatory mediators & ↓ immune response
Adverse effects of glucocorticoids
gi irritation
adrenal suppression
↓ immunity
Modifications to C-21 glucocorticoids/ mineralocorticoids affecting activity
need -OH required for mineralocorticoid & important for glucocorticoid functions
Modifications to C-11 glucocorticoids/ mineralocorticoids affecting activity
-OH =active form
=O =prodrug form
Modifications to C-3 glucocorticoids/ mineralocorticoids affecting activity
keto(=O) + 4,5 double bond required for activities of both
Pharmacodynamics of adrenal cortex hormones
lipid soluble
slow absorption in insoluble salts or oily vehicles to keep in place
Pharmacokinetics of adrenal cortex hormones
well absorbed by route ROA
highly protein bound
microsomal metabolism:cytochrome P450 oxidation & glucuronidation
Therapeutic uses of adrenal cortex hormones
must remember adrenal suppression
may want to give every other day, ↓ dosage gradually or combine w/ a cytotoxic agent
Hydrocortisone
Short-acting, active form
equal Glucocorticoid & mineralocorticoid action
Prednisone
Intermediate-acting, pro-drug
more glucocorticoid than mineralocorticoid action
Dexamethasone
Long-acting, all glucocorticoid action, no mineralocorticoid action
Uses of mineralocorticoids
To treat Addison's disease
Uses of Adrenaocorticoid antagonists
to treat Cushing's disease
Actions of Adrenocorticoid antagonists
Decrease synthesis of hormones
cytotoxic action
MAO-B inhibitors
-(↑ Dopamine= shuts down ACTH secretion)
Hormones to manipulate functions of growth or reproduction
Growth hormones
Androgens
Estrogens
Progestins
Gonadotropins
Uterine stimulants
Growth hormones
Somatotropins-sythetics
Potential for abuse
Adrogens
from testes & adrenal glands
used to increase muscle mass & increase appetite
-used in very sick patients
-also for antiestrogenic effects
Massive necrosis
whole lobule becomes necrotic
- but not all lobules
Drug, toxic plants & chemicals
Vitamin-E- selenium deficiency
Mosaic pattern of liver change
large red & yellow areas of the liver
Similar to lobular pattern but more severe w/ larger gross lesions
2 causes of cirrhosis
Chronic active hepatitis
Post - necrotic healing
Chronic active hepatitis
idiopathic but important disease of dogs
causing liver Cirrhosis
Post necrotic Cirrhosis
Fter massive necrosis liver undergoes healing, though most rarely survive the massive necrosis
2 causes of liver fibrosis
chronic heart failure
chronic cholangitis
Fibrosis of liver
scarring w/o nodular regeneration
= retains normal shape, w/ white/tan lobular pattern
Chronic heart failure in causing liver fibrosis
causes chronic passive congestion
- an irregular surface w/ small nodules or sheet of fibrin = nutmeg liver
- makes liver very firm, but retains it's shape
Chronic cholangitis in causing Fibrosis of liver
bile duct inflammation
- liver becomes firm & has lobular pattern
Focal / Multifocal liver changes
generally caused by infections disease
produces multiple foci pf necrosis or nodules
4 Neoplasms of liver
hepatocellular carcinoma
Billary adenoma / adenocarcinoma
Metastatic carcinomas / sarcomas
Nodular hyperplasia
Liver Cirrhosis
Fibrosis & regeneration
Produces nodules that distart the normal architecture
Hepatocellular carcinoma
In dog
Malignant
can be single masses, or large & multilobulated
brown w/ yellow (fat) & red (hemorrage)
Biliary adenoma / adenocarcinoma
In dog & cat
Adenoma - single nodules, often cystic & filled w/ green or clear fluids (cat)
Adenocarcinoma - multiple, firm, white nodules w/ depressed centers (dog)
usually incidental findings
Metastatic carcinoma / sarcoma
occurs commonly in the liver
multiple, firm white nodules
Hemangiosarcoma in liver
can be primary or secondary
when primary appear as mulitiple, red nodules & blood-filled cysts
Nodules hyperplasia
incidental finding (older dogs)
Solitary, discrete nodules
soft & tan from fat accumulation
Cause of small liver
Portosystemic shunts
- congenital or acquired
- acquired - following chrinoc disease & cirrhosis causes↑in pressure backing up blood in portal system
Significance of distended bile ducts
firm
seen in cattle & sheep w/ liver flukes
become visible on surface of liver as thick, white tortuous channels
Hemorrhage of the Gall Bladder
can occur w/ any bleeding disorder
DIC
anticoagulant toxicosis
Fibrinous cholecystits
inflammation of gall bladder
can occur w/ salmonella infection but not always seen
Significance of thick viscous opaque bile
seen in animals w/ amonexia for a few days
Cystic hyperplasia of gall bladder
uncommon & incidental finding in dogs
the mucosa of gall bladder contains many small cysts or larger papillary / nodular growth
Diagnostic pieces of skin disease
1. Histopath - "a must"
2. Signalment
3. History
4. Location of lesion(s)
5. Season
6. Presence / absence of pruritis
Why all skin diseases called dermatitis
inflammatory cells have to come from blood vessels = in dermis
Pustules
Aggregates of neutrophills (+ possibly eo's) w/ in epidermis
yellow - white
don't last long, before bursting & leaving a crust
Crust
a scab of dried up accumulated
Keratin, inflammatory cells, serum & bacteria
left when pustules burst.
Causes of pustular dermatitis
superficial bacterial infections
folliculitis
pemphigus foliaceus
Superficial bacterial infections
can cause pustular dermatitis
usually a staph infection
pustules occur in Keratin layer
Folliculitis
inflammation of hair follicle
by infection w/ bacteria, fungi or mites causes pustules to form over the follicle
Pemphigus Foliaceus
autoimmune disease, causing pustular dermatitis
Antibodies against intercellular bridges b/w Keratinocytes
- cells separate, detach & float into the pustule
- detached calls = acanthocytes / acantholytic cells
Vesicles
cavaties w/ in or beneath the epidermis fiiled w/ fluid (edema Fluid)
less - than 5mm
" blisters "
Bulla
Same thing as vesicles only bigger than 5mm
Spongiosus
Edema between keratinocytes
common w/ dermatitis
Intracellular Edema
Edema w/ in Keratinocytes
Hydropic degenaration
- Intracellular edema w/in basal epidermal cells appears as vacuoles
- Specific features of lupus erythematosis & dermatomyositis
- can occur w/ drug reaction
Lupus erythematosis
an autoimmune disease that causes hydropic degeneration
likes to manifest on nose of dogs & around eyes
- can result in depigmentation
Ballooning Degeneration
Intracellular edema w/in superficial Keratinocytes
- a feature of viral skin diseases
- POX
- FMD
Pemphigus vulgoris in the skin
an autoimmune disease
causes suprabasilar vesicles w/ acantholytic cells
antibodies directed @ Keratinocytes
Bullous Pemphigoid
an autoimmune disease
antibodies againts basement membrane
cause subepidermal vesicles
Macule
flat, discolored area of skin < 1cm diameter usually red
Papule
a slightly raised area w/in the skin usually red
Necrotizing dermatitis
begins as macules / papules
these burst to form crusts & ulcers
Erythema multiforme
Uncommom disease necrotizing dermatitis causes necrosis of single keratinocytes throughout epidermis
caused by adverse reactions to drugs for systemic infection & neoplasia
Toxic epidermal necrolysis
an uncommom disease causing necrotizing dermatitis more severe form of erythema multiforme
Epidermal necrosis across thickness
caused by adverse reaction to drugs for systemic infections or neoplasms
causes of necrotizing dermatitis
erythema multiforme
toxic epidermal necrolysis
burns
photo sensitization
Photosensetization
a necrotizing dermatitis
mostly in large animals
affects only non-pigmented skin
caused by ingestion of s photodynamic agent in feed or can occur secondary to chronic liver disease
causes of exudative & ulcerative dermatitis
allergic skin disease
eosinophilic granuloma complex
allergic contact dermatitis
Irritant contact dermatitis
Pyotraumatic dermatitis
Allergic skin disease
most coomon cause of exudative dermatitis
most allergies in animals manifest as skin diseases
- intensely pruritic
Atopy
an inhalant allergy
most common cause of allergic skin disease
Eosinophilic granuloma complex in the skin
group of 3 diseases that are all caused by hypersensitivity reaction(allergy)
Characterized by eo's & macrophages can produces nodules / papules and ulcers
1. Eosinophilic granuloma
2. Rodent ulcer
3. Eosinophili plaque
Allergic contact dermatitis
allergic skin disease caused by contact w/ allergic substance = delayed-type hypersensitivity
- usually in sparsely haired areas
HyperKeratotic diseases
Seborrhea
Parakeratotic hyperkaratosis(parakeratosis)
OrthoKeratotic hyperkeratosis(hyperKeratosis)
Irritant contact dermatitis
caused by contact w/ irritating substances
i.e. drugs, soaps, acids
usually in thinnly hained areas
lesions appear more immediately than allergies may cause erythematous papules / ulcers / crusts
Pyotraumatic dermatitis
" hot spots "
severe exudative dermatitis in dogs
caused by self-inflicted trauma from biting / scratching pruritic areas from allergic skin disease
Hyperkeratosis
excess Keratin on skins surface
- grossly produces flakes / scales on skin
OrthoKeratotic hyperkeratosis
" hyoerkeratosis " Keratinized cells lack nuclei
Parakeratotic hyperkeratosis
" parakeratosis "
Keratinized cells retain their nuclei
is diagnostic of zinc-deficiency and vitamin A- responsive dermatoses, when really severe
Seborrhea
excess sebaceous gland secretions may be dry or oily, flakes / scales on skin
can be a primary - inherited disease or secondary w/ other skin disease
Hyperplastic Dermatitis
= acanthosis
can occur w/ any chronic skin disease
skin appears thickened & may have a leathery texture
may appear w/ increased pigmentation
Acanthosis
Hyperplasia of the epidermis
Lichenification
leathery texture of skin
4 Cutaneous neoplasias
Squamous cell carcinoma
Melanoma
Papilloma
Intrecutaneous cornifying epithelioma
= Keratoacanthoma
Squamous cell carcinoma
a malignant neoplasm
- usually in non-pigmented skin due to exposure to sunlight
skin & oral cavity of dogs
Penis, eye & stomach of horse
eye of cow
nose, pinna - cat
Treat w/ radiator theraphy
Melanoma
tumor of melanocytes
can be benign or malignant
pigmented or nan-pigmented
Dog: skin - usually benign
mouth - usually malignant
Horse: perineum of gray horse = many benign masses
Papilloma
wart, caused by papilloma virus
multiple tumors found in young animals
- regress over several months
- cattle mostly
( horses, & dogs)
Intarcutaneous cornifying epithelioma
Keratoacanthoma
cane benign tumor of dogs
- squamous epithelial cells
6 adnexal Neoplasms
Basal cell tumor
Trichoepithelioma
Pilomatricoma
Sebaceous gland tumor
Sweat gland tumor
Perianal gland tumor
Basal cell tumors
Neoplasms of basal cells only
- benign in the dog & cat
Trichoepithelioma
benign tumor of dog
- from hair follicle
- produces hair & hair follicles
Pilomatricoma
benign tumor of dogs
- from hair marix
- only makes hair
Sebaceous gland tumor
adenomas or adenocarcinoma
one of most common tumor of dog skin
Sweat gland tumors
adenomas or adenocarcinomas - more common rare tumor of dogs
- Produces sweat so can become cystic
Perianal gland tumor
usually benign tumor of dogs
- very commom, especially in male dogs
- from perianal glands
7 Dermal Neoplasms
Histocytoma
mast cell tumor
fibroma / fibrosarcoma
Sarcoid
Lipoma
Plasma cell tumor
Histiocytoma
very common, benign tumor of dogs
- usually from the langerhans cells
in young dogs
- grow very fast
- may regress own it's own
Mast cell tumors
very common
benign or malignant
- occur mainly in dogs, but also cat & horse
Fibroma
benign tumor of dogs & cats from fibroblasts
Fibrosarcoma
malignant tumor of cats from fibroblasts
- can be spontaneous or secondary to vacination
locally invasive but don't metastasize well
Anal sac carcinomas
metastasize readily
- more common in female dogs
Sarcoid
benign but does recurr
- a tumor of fibroblasts of horses
lipoma
very common benign tumor of dog
- from adipocytes
Plasma cell tumor
benign tumor of dog
from plasma cells in skin + oral cavity
Hemangioma
benign tumor of vascular epithelium , in dogs
Hemanigosarcoma
malignant tumors of endothelium
- recur locally
- metastasize
Mosaic pattern of liver change
large red & yellow areas of the liver
Similar to lobular pattern but more severe w/ larger gross lesions
Massive necrosis
whole lobule becomes necrotic
- but not all lobules
Drug, toxic plants & chemicals
Vitamin - E - Selenium deficiency
liver cirrhosis
fibrosis & regeneration
Produces nodules that distort the normal architecture
2 causes of cirrhosis
Choric active hepatitis
Post - necrotic healing
Chronic active hepatitis
idiopathic but important disease of dogs causing liver cirrhosis
Post necrotic cirrhosis
after massive necrosis liver undergoes
healing, through most rarely survive the assive necrosis
2 causes of liver fibrosis
chronic heart failure
chronic cholangitis
Fibrosis of liver
scarring w/o nodular regeneration
= retains normal shape, w/ white/tan lobular pattern
Chronic heart failure in causing liver fibrosis
causes chronic passive congertion
- an irregular surface w/ small nodules or sheet of fibrin = nutmeg liver
- makes liver very firm, but retains it's shape
Chronic cholangitis in causing fibrosis of liver
bile duct inflammation
- liver becomes firm & has lobular pattern
Focal / Multifocal liver changes
generally caused by infections disease
produces multiple foci of necrosis or nodules
Physical disturbances of the oral cavity
Cleft palate
Cleft palate
a hereditary defect where the hard palate fails to close
-predisposes to aspiration pneumonia
Causes of vesicles in the oral cavity
usually caused by viral agent
can also be autoimmune
Vesicular diseases of the oral cavity in large animals
Lesions (vesicles) all look the same
Foot & mouth-bo,ov,sw
vesicular stomatitis-eq,bo,sw
vesicular exanthema-sw
swine vesicular disease-sw
vesicular diseases of other (non-large) animals
feline calici virus
Herpes B virus-primates
pemphigus vulgaris-ca,fe
bullous pemphigoid-ca,fe
Feline calici virus
produces vesicles in the oral cavity
usually burst quickly leaving ulcers
Herpes B virus
produces gingival ulcers (cold-sores) in non-rhesus monkies
-in man & rhesus monkies is fatal
Pemphigus vulgaris/bullous pemphigoid
autoimmune diseases of dogs & cats
produces ulcers that quickly burst leaving ulcers
7 ulcerative diseases of the oral cavity
BVD
malignant catarrhal fever
Bluetongue
uremia
eosinophilic granuloma complex
aeromonas
trauma
6 proliferative diseases of the oral cavity
Contagious ecthyma
bovine papular stomatitis
fusobacterium necrophorum
actinobacillus/Actinmyces
gingival hyperplasia
neoplasia
6 neoplasias of the oral cavity
Melanoma
squamous cell carcinoma
fibrosarcoma
epulis
papilloma
tooth germ tumors
Lesions of BVD in the oral cavity
Produce ulcer in the mouth
-but primarily affect the esophagus & small intestines
Malignant catarrhal fever
a gamma herpes virus carried by sheep but affects cattle
produces ulcers in the oral cavity
Bluetongue
an insect vectored orbivirus that affects sheep
causes ulcers in the mouth, makes the tongue swell & turn blue
also causes hemorrhage in the forestomach
Uremia affecting the oral cavity
accumulation of toxins in the blood caused by renal failure
-cause ulcers on the tongue & the stomach
Eosinophilic granuloma complex
a group of 3 diseases caused by hypersensitivity reactions
-cause ulcers in the mouth & skin
Aeromonas
gram - bacterial infection
affects fish & reptiles
-cause septicemia
-necrosis w/ hemorrhage in the mouth & other organs
Contagious ecthyma
a pox virus affecting sheep & goats
-cause crusty lesions on lips, face & feet
Bovine papular stomatitis
a parapox virus
-causes circular, raised lesions in the mouth & esophagus
-usually an incidental finding