Gastroenterology Exam 2

Front 1

glandular part of the equine stomach:
- what does it secrete for protection?
- what causes blood flow to increase to this region?

Back 1

- secretes mucus and bicarb
- PGE2 increases blood flow

Front 2

equine stomach
- which part most susceptible to injury?
- which part has the fastest epithelial turnover?

Back 2

- stratified squamous epithelium (non-glandular part) most susceptible to injury
- glandular part has highest epithelial turnover

Front 3

what are two ways the non-glandular part of the equine stomach protects itself from injury?

Back 3

1. stratified squamous epithelium
2. inter- and intracellular buffering system

Front 4

what cells in the stomach secrete acid? Which cells secrete pepsin?

Back 4

- acid secreted by parietal cells
- pepsin secreted by chief cells

Front 5

what is pepsin?

Back 5

a proenzyme, secreted by gastric Chief cells, which becomes a protein-digesting enzyme when activated by the acidic pH of the stomach

Front 6

what are five proposed causes for gastric ulcers in the horse?

Back 6

1. NSAIDs (↓ PGE synthesis)
2. stressors like disease
3. training, breeding, showing - stress
4. high grain (textured feeds) diet
5. H. pylori (?)

Front 7

gastric ulcers in foals:
- % in sick foals
- % that have progressed to duodenal ulcers in necropsied foals
- which part of the stomach?

Back 7

- 25-50% in sick foals
- 5% necropsied foals have duodenal ulcers
- usually stratified squamous part of stomach

Front 8

gastric ulcers in adult horses:
- activity level that predisposes?
- which type of horse most common?
- which part of the stomach?

Back 8

- horses in training most common
- race horses up to 66%
- squamous most common; glandular < 20%

Front 9

a foal laying in dorsal recumbency (cast on their backs) probably has what?

Back 9

colic from an ulcer

Front 10

what are four clinical signs of gastric ulcers in foals?

Back 10

1. colic
2. reluctance to eat (it hurts to eat)
3. gas/diarrhea
4. bruxism

Front 11

what is the major difference between adult horses and foals in their clinical presentation of ulcers?

Back 11

adults DO NOT GET DIARRHEA from gastric or SI ulcers unless they are about to die

Front 12

what would a horse with a picky appetite, due to an ulcer, prefer to eat?

Back 12

hay over grain; this is not normal behavior

Front 13

what are 6 things on Hx that might help identify a gastric ulcer in a foal?

Back 13

1. DIARRHEA
2. disease
3. orphan or reject
4. weight loss
5. poor doer

Front 14

what are 5 things on PE that might help identify a gastric ulcer in a foal?

Back 14

1. DIARRHEA
2. poor body condition
3. picky eater - sucks and stops
4. concurrent illness
5. colic

Front 15

what are 5 things on Hx that might help identify a gastric ulcer in an adult horse?

Back 15

1. Heavy work load (training, breeding)
2. NSAID therapy
3. High grain diet
4. poor appetite
5. recurring colic
(Note: diarrhea is not a typical sign of gastric ulcers in ADULT horses)

Front 16

what are 3 things on PE that might help identify a gastric ulcer in an adult horse?

Back 16

1. weight loss
2. poor condition
3. splinting - low grade abdominal pain that looks like abdomen is raised up a little

Front 17

what are 3 tests to diagnose gastric ulcers in horses?

Back 17

1. GASTROENDOSCOPY - most common
2. Fecal Occult Blood - only foals; adults digest blood too much for a reliable test
3. Gastric Mucosa Permeability Test - rarely done

Front 18

comment on using fecal occult blood for diagnosis of gastric ulcers in horses

Back 18

- not accurate in adult horses due to colonic flora digestion of blood
- may be an indicator in young foals

Front 19

how is a gastric mucosa permeability test performed to diagnose ulcers in horses?

Back 19

1. administer 1 g/kg sucrose via OG tube
2. note: sucrose is a disaccharide and must be broken down before absorbed in a healthy digestive system
3. presence of sucrose in urine at 120 minutes indicates gastric mucosal injury

Front 20

gastroendoscopy in horses to diagnose gastric ulcers:
- how long do you withhold feed?
- how long do you withhold water?
- when withholding feed, what should you prevent the horse from doing?
- how do you restrain them for the procedure?

Back 20

- withhold feed and water for 12 hours
- make sure they don't eat their bedding or anything else
- restraint: sedate with detomidine or xylazine and twitch

Front 21

gastroendoscopy in horses to diagnose gastric ulcers:
- length of endoscope?
- what parts of the stomach do you examine?
- if the horse is/has colicked, what should you make sure to do before removing the endoscope?

Back 21

- 3 m endoscope
- examine the greater and lesser curvature, margo plicatus, and if possible, the pylorus
- if the horse is colicky or has a Hx of recent colic, deflate the stomach

Front 22

which part of the horse's stomach do gastric ulcers have a poorer prognosis?

Back 22

glandular part (versus squamous)

Front 23

what pathological lesion will you often see on endoscopy of a horse with an ulcer in the squamous part of the stomach?

Back 23

hyperkeratosis of the squamous epithelium with punctate ulcers

Front 24

what are three basic ways to conservatively manage gastric ulcers in the horse?

Back 24

1. change the horse's lifestyle: turnout on pasture
2. change feed: ↑ roughage and continuous feeding (to prevent excess stomach acid)
3. consider medications

Front 25

if treating gastric ulcers with medications in the horse, how long do you treat and when do you recheck?

Back 25

3 weeks

Front 26

what are four medications used in the treatment of gastric ulcers in the horse, and their mechanism of action?

Back 26

1. omeprazole: PPI
2. ranitidine: H2 blocker
3. cimetidine: H2 blocker
4. sucralfate: protectant

Front 27

duodenitis-proximal jejunitis in the horse:
- gross pathological lesion
- what 3 things happen as part of the disease process?
- why is this a life-threatening condition?

Back 27

- inflammation and thickening of the proximal small intestine
1. EXCESSIVE FLUID AND ELECTROLYTE SECRETION INTO THE SI
2. diminished SI motility
3. results in accumulation of large volumes of fluid in the horse's SI and stomach
- life-threatening because horses can't vomit, so their stomach can burst

Front 28

what are three general etiologies of duodenitis-proximal jejunitis in the horse?

Back 28

1. infectious
2. dietary indiscretion
3. ambient heat, exercise - exercise induced ileus

Front 29

what are five infectious causes of duodenitis-proximal jejunitis in the horse?

Back 29

1. Clostridium difficile
2. Clostridium perfringens
3. Salmonella
4. Enteric bacteria like E. coli (rare)
5. parasites (rare)

Front 30

what are two ways that diet can cause duodenitis-proximal jejunitis in the horse?

Back 30

1. overeating
2. rapid change in diet

Front 31

duodenitis-proximal jejunitis (DPJ) in the horse versus a SI surgical lesion (i.e., strangulation):
- degree of pain
- HR
- MM color
- NG tube reflux?
- rectal findings
- US exam
- abdominocentesis

Back 31

- degree of pain - DPJ: moderate; strangulation: severe unless ruptured
- HR - DPJ: 60-70; strangulation: 60 - >100
- MM color - DPJ: dark red to pink; strangulation: pink to purple
- NG tube reflux - DPJ: sometimes makes them feel better; strangulation: reflux present
- rectal findings - DPJ: moderate SI distention, thickening of wall; strangulation: tight loops of SI
- US exam - DPJ: moderate distended DI, thick walls, some motility; strangulation: very distended SI, little or no motility
- abdominocentesis - DPJ: ↑ proteins; strangulation: ↑ proteins and cells

Front 32

what are 5 ways to treat duodenitis-proximal jejunitis in the horse?

Back 32

1. relieve GI pressure with a NG/OG tube and reflux every 2 hours
2. fluid and electrolyte replacement therapy
3. NSAIDs
4. prophylactic antibiotics
5. ± anti-gastric ulcer meds

Front 33

what organism causes proliferative enteropathy in horses?

Back 33

Lawsonia intracellularis

Front 34

what age of horses are affected by proliferative enteropathy?

Back 34

weanling to yearling foals

Front 35

what is the pathogenesis of proliferative enteropathy in foals?

Back 35

- Lawsonia intracellularis invades crypt cells of ILEUM
- mitotic division of hyperplasia
- thickened, corrugated gut, which has a limited brush border → malabsorption
- weight loss and hypoproteinemia (hypoalbuminemia)

Front 36

what does a foal with proliferative enteropathy (Lawsonia) look like?

Back 36

- they look scrawny and ADR
- ± limb edema

Front 37

what part of a foal's history (along with PE findings) might clue you on to proliferative enteropathy (Lawsonia)?

Back 37

Hx of adequate access to food, but poor weight gain

Front 38

what are 5 PE findings that correlate with proliferative enteropathy (Lawsonia)?

Back 38

1. small
2. thin, poor hair coat
3. quiet attitude
4. peripheral edema
5. skin lesions and other secondary infections

Front 39

what are four basic diagnostic tests and findings for proliferative enteropathy in the horse?

Back 39

1. CBC - ↓TP, ± anemia
2. blood chemistry: ↓TP, ↓albumin
3. abdominal ultrasound: thickened, but NOT USUALLY DISTENDED SI (up to 6-12 mm wall thickness)
4. IFA test for serum antibodies

Front 40

what are four antibiotics that you can use to treat proliferative enteritis in the horse?

Back 40

1. erythromycin ± rifampin
2. chloramphenicol
3. oxytetracycline
4. doxycycline

Front 41

what is the prognosis of proliferative enteropathy (Lawsonia) in a foal?

Back 41

usually good if foal is not too debilitated

Front 42

Rhodococcus equi enteritis in the horse:
- age of horse
- grossly, why does this respiratory disease spread to the GI?
- how does R. equi get to other parts of the body?

Back 42

- foals 2-5 months of age
- enteric disease is due to extrapulmonary disorders associated with lymphatic infection
- pathogen resides in macrophages and that is how they spread

Front 43

what are 7 Hx/CS of Rhodococcus equi enteritis in foals?

Back 43

1. respiratory disease on the farm and/or foal
2. diarrhea
3. weight loss
4. low-grade colic
5. low-grade fever
6. anorexia
7. other immune-mediated diseases

Front 44

what are typical CBC results of Rhodococcus equi enteritis in a foal? (4)

Back 44

1. leukocytosis
2. neutrophilia
3. ↑ fibrinogen
4. ± thrombocytosis

Front 45

what are typical ultrasound findings of Rhodococcus equi enteritis in a foal's
- thorax?
- abdomen?

Back 45

- thorax: evidence of abscesses
- abdomen: evidence of abscesses, peritonitis, thick bowel

Front 46

what are 3 antibiotics used to treat Rhodococcus equi enteritis in the foal?

Back 46

erythromycin, azithromycin, clarithromycin (all ± rifampin)

Front 47

how long do you treat R. equi enteritis in a foal with antibiotics? What clinical signs should you look for?

Back 47

- treat for one week after CBC is normal
- watch for diarrhea in both the foal and the mare

Front 48

what is the definition of endotoxemia?

Back 48

endotoxin in the blood

Front 49

what are the three parts of endotoxin and their basic functions?

Back 49

1. O-antigen: hydrophilic chain that projects into the environment; high variability from bacteria to bacteria
2. Lipid A: constant across bacteria; hydrophobic and buried in the cell membrane
3. Polysaccharide core, which connects the O-antigen to the Lipid A moiety

Front 50

what is the basic way that the immune system is activated by endotoxin?

Back 50

1. LPS binds to macrophages and cell receptors
2. stimulates a number of pathways including cytokine release and activation of gene transcription of inflammatory mediators

Front 51

what are six basic clinical signs of early-stage endotoxemia in the horse?

Back 51

1. restless
2. depressed
3. inappetent
4. febrile
5. ↓ GI sounds
6. mild to moderate evidence of CV compromise (i.e., horse is becoming shocky)

Front 52

what are four indicators of mild/moderate CV compromise associated with low-dose endotoxemia in the horse?

Back 52

1. injected MM
2. ↑ CRT
3. tachypnea/tachycardia
4. hypotension

Front 53

how long does low dose endotoxemia last in the horse?

Back 53

if single dose, 8-12 hours

Front 54

what are 8 clinical signs of high-dose endotoxemia in the horse?

Back 54

1. circulatory collapse (↑↑CRT, etc.)
2. negative energy balance → stupor and anorexia
3. dehydration
4. poor pulses, cold extremities
5. fever first → hypothermia
6. sweating, shivering, muscle fasciculations
7. coagulopathy: petechia, clotting disorders
8. infarcts and associated signs followed by bleeding tendencies
- note, #7, #8 consistent with DIC

Front 55

what are five things to do to treat endotoxemia in the horse?

Back 55

1. early and aggressive CV resuscitation
2. remove causative agent
3. neutralize circulating endotoxin
4. block inflammatory cascade
5. prevent laminitis

Front 56

CV resuscitation for endotoxemia in horses: what are three things to use to restore blood volume?

Back 56

1. IV polyionic solutions
2. plasma
3. hetastarch

Front 57

CV resuscitation for endotoxemia in horses: which electrolytes need to be supplied?

Back 57

bicarb, potassium, calcium

Front 58

what is the shock dose of IV fluids in the horse?

Back 58

45 mL/kg/hour

Front 59

when a horse is in endotoxic shock, how much plasma do you give to adults? Neonates?

Back 59

- adults: 5 liters
- neonates: 1-2 liters

Front 60

what are 7 things to do to prevent laminitis in a horse with endotoxemia?

Back 60

1. fluid resuscitation
2. ICE BOOTS 24/7
3. flunixin
4. pentoxifylline (antiinflammatory and supports capillary flow)
5. heparinized plasma to prevent clots
6. insulin with glucose to promote cell uptake
7. check glucose q 2-4 hours

Front 61

what are the basic causes of endotoxemia in
- adult horses? (2)
- neonatal foals? (2)

Back 61

- adult horses: LI lesions (both surgical and medical); any gram negative infection in other viscera
- foals: gram negative septicemia; local (e.g. umbilical) infections

Front 62

what are four diseases caused by Gram negative infection in horses that can cause endotoxemia?

Back 62

1. pleuropneumonia
2. liver abscess
3. abdominal abscess
4. pyelonephritis

Front 63

what are two things that you can give a horse with endotoxemia to neutralize circulating endotoxin? What is the basic way these work?

Back 63

1. hyperimmune plasma and serum - contains J5 antibody against endotoxin core
2. Polymyxin B - binds to endotoxin

Front 64

what is a potential complication of administering Polymyxin B to a horse with endotoxemia?

Back 64

renal injury

Front 65

what is a potential complication of administering Banamine (flunixin meglumine) to a horse with endotoxemia?

Back 65

since it is a non-specific COX enzyme blocker, it reduces PGE synthesis in the kidney and gut. So renal capillary necrosis and gut injury due to ↓ blood flow.

Front 66

pentoxifylline:
- class of drug
- mechanisms of anti-inflammatory action
- what drugs should not be given with pentoxifylline and why?

Back 66

- methyl xanthine derivative
- ↓ macrophage and PMN inflammatory response (↓TNF, ↑IL-10); ↑ RBC deformability
- since this works by up-regulating prostacyclin synthesis, it should not be given with NSAIDs

Front 67

why are corticosteroids not typically used in horses to reduce the inflammatory response associated with endotoxemia?

Back 67

because there is a risk of laminitis with corticosteroids and although low doses can be beneficial, you may get sued if the horse develops laminitis

Front 68

what type of heparin should you use to prevent micro-thombi formation in horses with endotoxemia?

Back 68

because low MW heparin effectively blocks micro-thrombi formation and does not agglutinate platelets

Front 69

what type ancillary anti-inflammatory drug can be given to horses with endotoxemia to prevent reperfusion injury? What is their mechanism of action? What are 2 examples?

Back 69

reactive oxygen scavengers - scavenge radicals formed by xanthine oxidase in injured epithelium
1. allopurinol
2. DMSO

Front 70

- when is the peak of the effects of endotoxemia in a horse? How does this correlate with prognosis?
- after how long is prognosis guarded in horse with endotoxemia that is under control?

Back 70

- endotoxemia effects peak at 6 hours. If the horse survives this, it is the first benchmark of improvement
- if the horse survives 24 hours, it has a guarded prognosis

Front 71

diarrhea in a horse is usually disease of which parts of the GI tract?

Back 71

cecum and large colon

Front 72

what are 6 functions of the equine large colon?

Back 72

1. fluid resorption
2. Na transport
3. bicarb secretion and absorption
4. microbial/protozoal/fungal flora
5. VFAs from fiber
6. ammonia production

Front 73

what are 6 things caused by injury to the large colon in the horse?

Back 73

1. watery manure (diarrhea)
2. acidemia (↓ resorption & ↑ loss of bicarb)
3. hyponatremia and hypokalemia
4. nutrient loss (→ weight loss)
5. hypoproteinemia, hypoalbuminemia
6. endotoxemia

Front 74

what are four general etiologies of acute diarrhea in the horse?

Back 74

1. Infectious causes
2. Toxins
3. Inflammatory bowel diseases
4. secondary to other diseases

Front 75

what are the two most important infectious causes of diarrhea in the horse? What are two others?

Back 75

1. Salmonella
2. Potomac Horse Fever
- clostridiosis
- endoparasitism

Front 76

what are three common toxic causes of acute diarrhea in the horse?

Back 76

1. Cantharidin (Blister Beetle in alfalfa hay)
2. NSAID administration
3. antimicrobial-induced (kills normal flora)

Front 77

what are five serovars of salmonella that cause acute diarrhea in horses? What is the most common?

Back 77

1. S. typhimurium (most common)
2. S. krefeld
3. S. anatum
4. S. infantis
5. S. dublin

Front 78

Salmonella is ubiquitous; what is the major bacterial/serovar-specific factor that causes disease in the horse?

Back 78

virulence factors - mucosal adhesion/invasion

Front 79

Salmonella is ubiquitous; what are four endogenous factors to the horse that may cause them to develop disease?

Back 79

1. immunocompromised - young, old, other dz, poor nutrition
2. antimicrobial therapy
3. abrupt change in diet or inappropriate diet
4. other medications that alter gut flora or gut health

Front 80

Salmonella is ubiquitous; what are three exogenous factors to the horse that may cause them to develop disease?

Back 80

1. infective dose
2. population density of susceptible hosts
3. environmental support of bacteria

Front 81

what are some things in the history of a horse with diarrhea that may point to salmonellosis?

Back 81

- exposure (horse show, hospital, etc.)
- stress
- signalment
- other affected horses on the farm
- antimicrobials, dietary change, etc.
- acute onset

Front 82

what are four syndromes of salmonellosis in horses?

Back 82

1. inactive disease
2. severe fibrinonecrotic typhlocolitis
3. sudden death
4. septicemia in foals

Front 83

severe fibrinonecrotic typhlocolitis caused by salmonella in horses:
- MM color
- why are limbs and muzzle cold?
- CBC
- GI signs

Back 83

- brick red to purple MM
- endotoxic shock causes peripheral ischemia → cold
- CBC: neutropenia, left-shift
- diarrhea

Front 84

what are three diagnostic tests for salmonella in horses?

Back 84

1. fecal culture
2. rectal mucosal biopsy - not routinely done because of PCR
3. Fecal PCR

Front 85

Fecal culture to diagnose salmonellosis in horses:
- how much to collect and in what transport medium?
- how many cultures should you submit and at what interval?
- comment on the sensitivity of this method

Back 85

- 5-10 grams of feces in selenite broth
- one sample per day, for 5 consecutive days
- if all 5 are negative, 95% chance it is NOT salmonella

Front 86

when is rectal mucosal biopsy most useful for diagnosis of salmonella?

Back 86

if feces is very watery (i.e., there is not quality sample for culture)

Front 87

what is the lower detection limit for PCR of salmonella in horse fecal samples?

Back 87

1 DNA copy per gram of feces

Front 88

what are the three general ways to treat salmonellosis in the horse?

Back 88

1. IV fluids
2. plasma
3. NSAIDs

Front 89

IV fluids for treatment of salmonellosis in the horse:
- how do you determine the amount of fluids to give?

Back 89

- 50-100 mL/kg/day maintenance
- % dehydration X BW in kg
- estimate ongoing losses and double the volume

Front 90

how much plasma is given to treat salmonellosis in
- adult horses?
- foals?

Back 90

- adult: 5 L minimum; repeat as needed
- foals: 1-2 L

Front 91

which NSAID is used to treat salmonellosis in the horse?

Back 91

flunixin meglumine (Banamine)

Front 92

what four things are given to a horse to replace its electrolytes when it has salmonella?

Back 92

1. bicarb
2. potassium
3. free choice water
4. salt lick

Front 93

comment on antibiotic use to treat salmonellosis in horses:
- what have studies shown with regards to mortality?
- if using prophylactic antibiotics: spectrum? Purpose? Side-effects?
- which antibiotic is good at killing salmonella?

Back 93

- early studies showed increased mortality with antibiotic use
- with prophylactic antibiotics: broad spectrum to prevent systemic dissemination, consider side effects (especially of aminoglycosides)
- fluoroquinolones will kill salmonella and don't have as bad of side-effects as aminoglycosides

Front 94

how long should you isolate new horses to prevent salmonella?

Back 94

2-4 weeks

Front 95

what are some good practices on the farm if a horse develops salmonellosis?

Back 95

- separate tools, clothes
- clean stall and feed horse last
- remove feces and place away from horses (including run off)
- disinfect stall, buckets, etc., and make sure they dry out

Front 96

shedding of salmonella in horses:
- what % are carriers?
- how long do subclinical horses shed?

Back 96

- horses are not carriers because there are no host-adapted species of Salmonella
- chronic shedders 1-3 months on average (as long as 2 years)

Front 97

what is the medical name for Potomac Horse Fever?

Back 97

equine monocytic ehrlichiosis

Front 98

what causes Potomac Horse fever?

Back 98

Neorickettsia risticii (part of the Anaplasmataceae family)

Front 99

how do you visualize Neorickettsia risticii, the causative agent of Potomac Horse Fever?

Back 99

small, gram-negative cocci that turn dark blue with Romanovsky's stain

Front 100

where does Neorickettsia risticii, the causative agent of Potomac Horse fever, reside in the body? (3)

Back 100

INTRACELLULAR
- macrophages
- colonic and SI epithelium
- colonic mast cells

Front 101

Potomac Horse Fever
- 3 major risk factors
- reservoir host
- how does the horse become infected?

Back 101

- nearby water; unvaccinated horse; warmer times of year
- organism resides in trematodes that infect snails and aquatic insects
- infected by ingesting infected trematode or infected aquatic insects

Front 102

what is the route of horse-to-horse infection of Potomac Horse Fever?

Back 102

none. Only acquired by ingestion of reservoir snails or insect vectors

Front 103

what is an important DDx for Potomac Horse Fever in horses?

Back 103

Salmonellosis

Front 104

what are clinical signs of Potomac Horse Fever?

Back 104

- like salmonella
- biphasic fever (2-4d then 10-14 days)
- Laminitis

Front 105

comment on the efficacy of the Potomac Horse Fever vaccine

Back 105

- vaccinated horses still develop fever, hypoproteinemia, and laminitis, but much milder
- vaccine doesn't protect against a new strain

Front 106

what are four general tests to diagnose Potomac Horse Fever?

Back 106

1. paired titers (IFA or ELISA) - acute and convalescent 2-4 weeks apart
2. culture - takes weeks
3. PCR of feces or blood (buffy coat) - do both; takes 2 hours
4. response to antibiotic therapy

Front 107

what is the drug of choice to treat Potomac Horse fever?

Back 107

oxytetracycline

Front 108

what are four general aspects of treating Potomac Horse Fever?

Back 108

1. specific antibiotics: OXYTETRACYCLINE (> doxycycline)
2. Supportive care, like salmonellosis
3. laminitis prevention
4. be aware of relapses

Front 109

what are two complications of IV oxytetracycline administration to treat Potomac Horse Fever?

Back 109

1. must be given dilute and very slowly because it can cause perivascular necrosis
2. too high of a dose can cause very bad colitis

Front 110

why is doxycycline inferior to oxytetracycline in the treatment of Potomac Horse Fever?

Back 110

- given PO (as opposed to oxytetracycline, which is given IV) and may not be well absorbed
- because peak blood concentration is lower, must be given twice as long

Front 111

Potomac Horse Fever vaccination:
- initial vaccine schedule
- what time of year do you vaccinate?

Back 111

- 2X at 2-3 wk. interval
- vaccinate in spring and mid-summer

Front 112

how does NSAID administration damage the horse's colon?

Back 112

- colon depends on production of PGE2 for blood flow and restoration of epithelium

Front 113

which part of the horse colon is especially susceptible to ulcers caused by NSAIDs?

Back 113

right dorsal colon

Front 114

when talking to horse owners, how do you really make sure whether or not the horse is on an NSAID?

Back 114

- ask if the horse is on medications
- also ask if on "pain meds" or "is the horse on butte" because owners often don't associate phenylbutazone as a medicine

Front 115

what are two common Hx indicators that may suggest that a horse is on phenylbutazone?

Back 115

1. performance horses
2. recent lameness

Front 116

what are 4 clinical signs and 1 clin path sign of NSAID GI toxicity in horses?

Back 116

1. low grade colic
2. soft manure/diarrhea
3. low grade fever (from endotoxemia)
4. ventral edema (from hypoalbuminemia)
- clin path: ↓ TP & albumin

Front 117

what are 3 diagnostic tests that can be performed to diagnose ulcers associated with NSAID toxicosis in the horse?

Back 117

1. Gastroscopy: gastric ulcers can lead to colon ulcers
2. ultrasound: assess bowel thickness; not very sensitive
3. fecal occult blood: unreliable (waste of time)

Front 118

ultrasound of the colon to diagnose NSAID-induced ulcers in the horse:
- where is the lesion most common?
- where do you place the US probe?
- what do you assess?
- sensitivity?

Back 118

- most common in right dorsal colon
- examine right caudal rib field
- assess bowel thickness (normal < 0.4 cm)
- not very sensitive

Front 119

why are we more concerned with colonic ulcers than gastric ulcers in the horse?

Back 119

because the bacterial load in the colon is high

Front 120

what is the goal of feed modification to treat colonic ulcers in the horse?

Back 120

pelleted feed that is high in fiber, to reduce the volume that is going through

Front 121

which antimicrobial is indicated to treat colonic ulcers in the horse?

Back 121

metronidazole

Front 122

what GI drug is often used to treat colonic ulcers in the horse?

Back 122

misoprostol (a synthetic PGE, but results are not proven)

Front 123

besides feed changes, antibiotics, and ± misoprostol, what other measures do you take to treat severe cases of colonic ulcers in the horse?

Back 123

fluids, plasma, and endotoxemia therapy

Front 124

what is a good way to treat chronic colonic ulcers in the horse?

Back 124

chronic pasture turnout with a horse buddy that won't cause stress: less stress, healthy diet

Front 125

what is the prognosis of colonic ulcers in the horse?

Back 125

guarded; depends on colon healing

Front 126

how long would you expect colonic ulcers to heal in a horse? What should you monitor in the course of this disease?

Back 126

- 3-6 months
- monitor blood protein and albumin levels

Front 127

what type of cells comprise the peritoneum?

Back 127

squamous mesothelial cells

Front 128

in the horse, what is formed as a result of inflammation of peritoneal mesothelium?

Back 128

fibrin

Front 129

what are 9 primary causes of peritonitis in the horse?

Back 129

1. parturition (very common)
2. proximal enteritis
3. intestinal ischemia, compromise
4. hemorrhage (e.g., kicked in the spleen by another horse; hemoglobin is irritating to the peritoneum)
5. uroperitoneum
6. parasitic migration
7. abscess (secondary to S. equi, R. equi)
8. neoplasia
9. gastric/intestinal perforation

Front 130

what are the 6 most common clinical signs of peritonitis in horses?

Back 130

1. fever
2. anorexia
3. abdominal pain (mild-moderate)
4. decreased gut sounds (peritonitis associated ileus; can reflux)
5. dehydration
6. ± diarrhea or dry feces (evidence of disrupted motility)

Front 131

what are two findings on a rectal palpation of peritonitis in the horse?

Back 131

1. ± increased free fluid
2. ROUGH or GRITTY feeling serosa of the intestine

Front 132

what are three things found on ultrasound of a horse with peritonitis?

Back 132

1. ↑ free fluid
2. increased cellularity
3. fibrin tags

Front 133

what is the most rewarding diagnostic test for peritonitis in the horse?

Back 133

abdominocentesis → cytology and culture

Front 134

interpreting abdominocentesis in the horse:
- what is normal color, TP, cell count, and WBC differential?
- color normal but clear large volumes (2)
- color blood tinged
- frank blood/hemorrhage
- cloudy
- presence of bacteria or infectious organisms

Back 134

- normal: clear yellow, TP < 1-2.5 g/dL; cell count < 5000 cells/μL, 24-60% neutrophils (assuming horse is on a good deworming program)
- color normal but clear large volumes: ascites or uroperitoneum
- color blood tinged: evidence of compromised bowel or intraperitoneal viscera
- frank blood/hemorrhage: splenic or vascular injury
- cloudy: high cell count associated with severe inflammation, compromised viscera, abscess, or neoplasia
- presence of bacteria or infectious organisms: septic peritonitis

Front 135

what are 3 aspects of aggressive treatment of peritonitis in the horse?

Back 135

1. stabilize the patient
2. ID and treat inciting cause
3. administer additional medications and treatments specifically for peritonitis

Front 136

what are five therapies for peritonitis in the horse?

Back 136

1. shock therapy (similar to endotoxemia)
2. broad spectrum antimicrobials (including anaerobes)
3. antiinflammatory drugs to ↓ inflammation and ↓ fibrin production
4. peritoneal lavage
5. if necessary, surgical intervention (e.g. surgical lesion, hemorrhage, exploratory)

Front 137

what are 3 broad spectrum antimicrobials used in the treatment of peritonitis in the horse?

Back 137

1. K-penicillin
2. gentamycin
3. metronidazole

Front 138

what are 5 things to administer to a horse with peritonitis to minimize inflammation and fibrin formation in the horse?

Back 138

1. NSAIDs: flunixin
2. lidocaine IV CRI: prokinetic and analgesic
3. DMSO
4. pentoxifylline
5. ± plasma

Front 139

what type of lavage is used to treat peritonitis in the horse?

Back 139

top to bottom lavage

Front 140

what are 5 things that top-to-bottom lavage in the horse with peritonitis "washes out" or dilutes?

Back 140

1. ↓ [] of bacteria and inflammatory mediators
2. remove degenerate neutrophils and cellular debris
3. eliminate accumulated blood
4. remove irritating foreign material
5. dilute adhesion-forming substrates such as fibrinogen and fibrin

Front 141

what are 3 limitations of top to bottom peritoneal lavage in the horse?

Back 141

1. may not reach entire abdomen
2. may cause inflammation
3. may disrupt clots - use with extreme caution in horses with evidence of hemorrhage

Front 142

prognosis of peritonitis in the horse:
- determinants
- mortality rate
- greatest risk factor

Back 142

- depends on cause, severity and duration
- 60% mortality rate
- highest risk associated with post-colic surgery

Front 143

what are 4 complications of peritonitis in the horse?

Back 143

1. LAMINITIS
2. diarrhea
3. ileus
4. fibrinous adhesions

Front 144

what are 6 common causes of chronic weight loss in horses that are largely based on animal care?

Back 144

1. poor dentistry
2. inadequate deworming programs
3. inadequate access to fresh water
4. inadequate diet
5. competition for feed
6. stress

Front 145

why would inadequate access to fresh water cause a horse to chronically lose weight?

Back 145

because they will eat less without sufficient water (think about eating a salty cracker without water)

Front 146

what is a "smile" in a horse?

Back 146

middle teeth tend to grow longer and make a curved occlusal surface. will disrupt wear by opening mouth when they move teeth laterally

Front 147

what are four disease processes that cause chronic weight loss in horses?

Back 147

1. inflammatory disease
2. infectious disease: GI or other
3. neoplasia
4. malabsorption/maldigestion

Front 148

what are 10 pieces of Hx information that you want to obtain about an individual horse when assessing chronic weight loss?

Back 148

1. diet
2. water
3. use
4. deworming program
5. vaccines
6. dental care
7. recent travel?
8. recent disease (e.g. pneumonia, strangles, bastard strangles)?
9. recent addition (e.g. is this horse being picked on by other horses)
10. supplements?

Front 149

what are 5 pieces of management-related Hx information you want to obtain when assessing a horse for chronic weight loss?

Back 149

1. feed - separate or group? Are they getting enough? Is a bully eating more than its fair share?
2. housing - mud floors burn more energy; more exposure to the elements burns more energy
3. schedule - do they have one? Horses are creatures of routine
4. pasture/turnout - grazing areas? flat areas with no pasture? adequate water? hay bales?
5. water source - is it freezing over in the winter?

Front 150

how can a horse without access to a source of natural water (e.g., pond or stream) acquire Potomac Horse Fever?

Back 150

mosquitos in the water trough, if ingested, may be carrying Neorickettsia

Front 151

what are 9 things to examine on PE and inspection of the premises when trying to diagnose why a horse is chronically losing weight?

Back 151

1. routine physical exam
2. check teeth
3. check diet
4. check water
5. fecal sedimentation for sand (use glove method)
6. fecal parasite exam
7. rectal palpation
8. ± CBC, chem, UA (may not be necessary)
9. abdominocentesis (may not be necessary)

Front 152

on a rectal exam of a horse with chronic weight loss, what should you palpate? (3)

Back 152

1. all viscera to check size, position
2. thickness of bowel
3. ascending aorta, internal iliac arteries

Front 153

what are five things on a rectal palpation of a horse, indicating disease, that might be consistent with chronic weight loss?

Back 153

1. thickened bowels; enlarged/malpositioned viscera
2. "grit" on serosa - peritonitis
3. high temperature
4. enlarged lymph nodes
5. can feel the liver (should not normally be palpable)

Front 154

if a specific diagnosis of chronic weight loss in a horse is not determined, what are 6 things to include in the initial treatment?

Back 154

1. change diet - change feed, increase calories, pulverized feed for old horse
2. decrease work
3. deworm
4. float teeth
5. change management of horse - for example, feed the bully horse separately from the bullied horse
6. monitor weight on a regular basis with weight tape/condition score q 2 weeks; train the owners to use a weight tape

Front 155

what are the three main functions of the liver?

Back 155

1. synthesis
2. metabolism
3. excretion

Front 156

what are three important things made by the liver that horse professors care about?

Back 156

1. albumen
2. clotting factors
3. glycogen

Front 157

how much liver can a horse lose before clinical signs?

Back 157

60-80%

Front 158

what is the prognosis of liver disease in the horse and what are three determinants of the prognosis?

Back 158

- guarded to poor
1. acute versus chronic
2. manageability of the horse
3. immediate response to treatment

Front 159

what is an important rule-out if you suspect a horse has hepatoencephalopathy due to liver disease?

Back 159

Rabies

Front 160

what are four clinical signs of hepatoencephalopathy in the horse?

Back 160

1. yawning
2. head pressing
3. circling
4. seizures

Front 161

what are 12 general clinical signs of horses with liver disease?

Back 161

1. poor body condition
2. change in attitude, stance, and stride
3. behavior (hepatoencephalopathy)
4. signs of ventral edema
5. something about feces that I missed in lecture
6. decreased appetite
7. weakness (like somnolence and depression)
8. acute dementia
9. depression due to colic
10. skin disease
11. acute yellow hue to MM
12. white haired animals: photosensitization

Front 162

what will running a PCV and CBC tell you in a horse has liver disease?

Back 162

- serum may be bright yellow from bilirubin
- serum may be cloudy
- ↑ WBC if there is infection
- ↓ TP, ↓ albumin and/or panhypoproteinemia

Front 163

how do blood liver enzymes correlate with liver disease in the horse?

Back 163

- leakage of tissue enzymes (2-4X increase)
- note: mild increase commonly occurs with many diseases and shipping
- chronic disease - less liver enzymes or no increase

Front 164

in the horse, what are the three helatoCELLULAR enzymes?

Back 164

1. sorbitol dehydrogenase (SDH)
2. aspartate aminotransferase (AST)
3. Lactate dehydrogenase (LDH)

Front 165

in the horse, what are the two helatoBILIARY enzymes?

Back 165

1. gamma glutamyltransferase (GGT)
2. alkaline phosphatase (ALP)

Front 166

SDH in the horse:
- specificity to liver
- half-life
- interpretation of elevation with respect to liver disease

Back 166

- liver specific
- very short half-life and unstable
- elevations indicate active disease

Front 167

AST in the horse:
- specificity to liver
- half-life
- interpretation of elevation with respect to liver disease

Back 167

- non-specific (muscle, liver, RBC)
- stable, long half-life
- it is sensitive, but you must rule out muscle and RBC diseases

Front 168

ALP in the horse:
- specificity to liver
- half-life
- interpretation of elevation with respect to liver disease

Back 168

- non-specific
- not used for liver disease

Front 169

LDH in the horse:
- specificity to liver
- half-life
- interpretation of elevation with respect to liver disease

Back 169

- non-specific (liver and muscle)
- intermediate half-life
- need concurrent measurement of CK to rule out muscle disease

Front 170

GGT in the horse:
- specificity to liver
- half-life
- interpretation of elevation with respect to liver disease

Back 170

- non-specific (biliary, GI, pancreas, renal), but only biliary dumps into blood, so very commonly used in the horse
- moderately long half-life and can be elevated for a prolonged period
- indicates disease, but note that it is naturally elevated in foals < 45 days

Front 171

what are 5 blood chemistry clin path indicators of liver disease in the horse?

Back 171

1. ↓ albumin
2. ↓ BUN
3. ↓ serum glucose
4. ↑ bilirubin (note this is non-specific; e.g., anorexia can cause this)
5. ↑ triglycerides

Front 172

anorexia in the horse causes an increase of what type of bilirubin?

Back 172

unconjugated

Front 173

with liver disease in the horse, what do you see with respect to bilirubin?

Back 173

- increase of both conjugated and unconjugated
- conjugated often > 25% of total

Front 174

with biliary obstruction in the horse, what do you see with respect to bilirubin?

Back 174

- increase of both conjugated and unconjugated
- conjugated is consistently > 25% of total due to outflow obstruction

Front 175

in the normal horse, what type of bilirubin predominates in circulation and what percentage of total bilirubin is it?

Back 175

unconjugated predominates > 75%

Front 176

with hemolytic disease in the horse, what do you see with respect to bilirubin?

Back 176

- increase of both conjugated and unconjugated
- conjugated often > 25% of total
- this is similar to liver disease, so you need to consider all clinical findings

Front 177

hepatobiliary disease in the horse and blood ammonia:
- its relation to hepatoencephalopathy
- why do we monitor it?

Back 177

- likely not the cause of hepatoencephalopathy
- most useful in monitoring RECOVERY of liver function

Front 178

hepatobiliary disease in the horse and bile salts:
- sensitivity
- how does feed intake affect the results?
- if elevated, what must you also consider besides liver disease?

Back 178

- very sensitive
- not altered by feeding
- bile salts can be elevated in horses that are icteric, but don't have liver disease

Front 179

what are 3 things useful about ultrasound in a horse with suspected hepatitis?

Back 179

1. evaluate size of the liver
2. evaluate architecture of the liver
3. guided biopsy

Front 180

technically, what should you do before obtaining a percutaneous liver biopsy in the horse?

Back 180

check clotting times

Front 181

percutaneous liver biopsy in the horse
- preparation of the animal
- where do you do the biopsy?
- what two things do you do with the biopsy after you get it?

Back 181

- surgical prep and local anesthetic
- right 11-14 ICS
- submit for histopath and culture

Front 182

what are 6 general things to do when you are treating hepatic disease in the horse?

Back 182

1. fluids ± glucose
2. electrolytes (especially potassium)
3. decrease ammonia (neomycin, mineral oil, lactulose)
4. minimize stress
5. sedate as needed
6. change diet

Front 183

Acute Hepatic Necrosis of horses:
- 2 other names
- etiology (3)
- what time of year
- epidemiology

Back 183

- Theiler's Disease or Serum Hepatitis
1. Prior administration of Equine biologics, such as tetanus antitoxin
2. dietary or environmental toxin
3. idiopathic
- most common in fall
- may see outbreaks

Front 184

what disease of horses is associated with some kind of toxicosis or reaction to an equine based biologic (e.g., tetanus toxin), and most commonly occurs in outbreaks in the fall?

Back 184

Acute Hepatic Necrosis/Theiler's Disease/Serum Hepatitis

Front 185

A peracute necrotic liver disease of foals 7-40 days old, characterized by sepsis and hepatitis caused by Clostridium piliformis

Back 185

Tyzzer's Disease

Front 186

Tyzzer's Disease in horses:
- gross pathological lesion
- age of horse
- etiology
- clinical signs

Back 186

- peracute hepatic necrosis
- foals 7-40 days old
- Clostridium piliformis from a mare carrier or from the soil
- CS: sepsis and concurrent hepatitis

Front 187

a perinatal infection in horses, resulting in weak or stillborn foals, occurring early or at term, characterized by weakness at birth, abnormal lung sounds, and death in hours or a few days

Back 187

Equine Neonatal Herpes Virus

Front 188

Equine Neonatal Herpes Virus
- route of infection
- 3 clinical signs

Back 188

- perinatal infection of early or term foal
1. weakness at birth
2. abnormal lung sounds
3. death in hours or a few days

Front 189

describe the chronicity of toxic hepatitis in the horse.

Back 189

It is a chronic liver disease (e.g., eating toxic plants for a long time and accumulating the toxic byproducts) with acute exacerbation, once the toxin reaches 5% BW

Front 190

what phytochemical most commonly causes toxic hepatitis in horses?

Back 190

pyrrolizidine alkaloids

Front 191

what are three histopathological lesions of toxic hepatitis in the horse?

Back 191

1. MEGALOCYTOSIS - gross enlargement of hepatocytes
2. cell death
3. fibrosis

Front 192

what are 3 plants that contaminate pasture, hay, or silage, that produce pyrrolizidine alkaloids and cause toxic hepatitis in the horse?

Back 192

1. Amsinckia
2. Senecio
3. Crotalaria

Front 193

what two plants are associated with Trifoliosis (photosensitization) in the horse?

Back 193

1. Alsike clover (Trifolium hybridum)
2. Kline grass (Panicum coloratum)

Front 194

what weather conditions are associated with Trifoliosis (photosensitization) in the horse?

Back 194

humid

Front 195

Trifoliosis (photosensitization) in horses
- gross pathological lesions
- causative agent
- prognosis

Back 195

- biliary fibrosis and hyperplasia
- likely due to mycotoxin that grows in clover and Kline grass.
- Px: good if caught early and horse is no longer exposed to the grass/clover

Front 196

what are 6 clinical signs of cholelithiasis in the horse?

Back 196

1. Recurrent, progressive colic
2. ± fever
3. jaundice
4. weight loss
5. hepatoencephalopathy
6. photosensitization (liver can't excrete porphyrins)

Front 197

in what age of horses is cholelithiasis most common?

Back 197

horses > 9 years

Front 198

what breeds of equids are affected by hyperlipemia?

Back 198

Ponies, Donkeys, Minature horses, Draft breeds, and rarely others

Front 199

what causes hyperlipemia in horses?

Back 199

anorexia leads to excessive mobilization of fats

Front 200

what is the gross pathological lesion that results in hyperlipemia in the horse?

Back 200

hepatic lipidosis

Front 201

what is the prognosis and treatment for hyperlipemia in the horse?

Back 201

- Px: is guarded to poor
- Tx: preventative treatment is the best approach

Front 202

preventing hyperlipemia in horses:
- who is at risk?
- what do you do if there are elevated serum triglycerides?

Back 202

- all susceptible breeds / species that are ill for more than 24 hours are at risk
- if elevated triglycerides: 5% glucose maintenance, slurry by NG tube, oral Karo syrup
- recheck triglycerides daily; if they continue to increase, provide more aggressive nutritional support

Front 203

what is the difference between hyperlipemia and hyperlipidemia in the horse?

Back 203

- hyperlipemia is the severe form in horses that leads to hepatic lipidosis
- hyperlipidemia may affect any breed of horse after several days of fasting and is characterized by elevated triglycerides (but not as high as hyperlipemia)
- with hyperlipidemia, in contrast to hyperlipemia, the serum is clear and not cloudy
- liver disease may still develop but much less rapidly
- response to ↑ energy in ration or IV fluids

Front 204

what is the most common form of colic?

Back 204

simple colic

Front 205

describe simple colic

Back 205

the most common form of colic, which may include gas distention, responds to first treatments, and because it is mild, the GI segment affected is rarely diagnosed.

Front 206

describe spasmodic colic
- auscultation
- what causes pain?
- possible causes?

Back 206

- excessive intestinal sounds on auscultation
- pain associated with spasmodic contractions
- may be due to impactions, or may represent resolution of a simple or gas colic

Front 207

what are two primary and two secondary causes of gastric dilitation in the horse?

Back 207

- primary: impaction, tympany
- secondary: ileus, SI obstruction

Front 208

what are two surgical approaches to gastric rupture in the horse?

Back 208

1. ventral midline, just behind xiphoid
2. 14 left rib - thoracotomy

Front 209

what should you do each and every time you examine a horse for colic?

Back 209

pass a stomach tube (may relieve bloat)

Front 210

what is the major cause of gastric rupture in the horse?

Back 210

overeating - excessive fermentation

Front 211

what part of the stomach ruptures in a horse with a gastric rupture?

Back 211

greater curvature

Front 212

what is the prognosis of gastric rupture in the horse?

Back 212

poor due to resulting peritonitis

Front 213

how do clinical signs in the horse change from gastric distention to rupture?

Back 213

they are extremely painful when the stomach is distended and suddenly become relaxed and depressed when it ruptures

Front 214

how could a gastric ulcer in the horse not start in the stomach?

Back 214

Gastric ulcers in the horse are usually accompanied by colon problems. Motility problems may cause reflux up into the stomach, causing ulcers.

Front 215

what are the two most common simple obstructions of the SI in horses?

Back 215

1. ileal impaction
2. adhesions (e.g. post-surgery)

Front 216

what type of feed is associated with ileal impactions in horses and why?

Back 216

Costal Bermuda hay. It is stiff, non-digestible hay. The intestines squeeze the water out of it and it becomes an obstruction

Front 217

SI obstruction and a concurrent fever are indicative of which disease in the horse?

Back 217

Anterior Enteritis

Front 218

what are 8 clinical signs of SI obstruction in the horse?

Back 218

1. mild to severe pain
2. dehydration occurs over several hours with obstruction
3. MM pale; rarely cyanotic; ↑ CRT
4. gastric reflux
5. reduced or no motility
6. distended SI per rectum
7. ↑ protein in peritoneal fluid
8. ↑ temp with anterior enteritis

Front 219

intestinal adhesions in horses
- clinical signs
- most common etiology
- timing of adhesion formation from this etiology

Back 219

- chronic intermittent colic due to OBSTRUCTION
- most likely from previous surgery
- usually occurs within 6 months from the time of surgery

Front 220

which part of the GI tract is prone to adhesions in the horse?

Back 220

small intestine (not LI or cecum)

Front 221

what are 3 types of strangulation obstruction of the SI in the horse?

Back 221

1. incarcerations
2. volvulus
3. intussusception

Front 222

what are 8 clinical signs of SI strangulation in the horse?

Back 222

1. severe pain
2. rapid dehydration
3. MM pale, cyanotic; ↑ CRT
4. gastric reflux
5. reduced or no motility
6. distended SI per rectum
7. peritoneal fluid rapid change from normal to ↑ protein, RBC, and WBC

Front 223

what are two major differences in the clinical signs between a simple SI obstruction and an SI strangulation in the horse?

Back 223

1. pain is more severe in strangulation
2. RBC and WBC in the peritoneal fluid with strangulation (i.e., inflammatory response and mesenteric hydrostatic pressure is more severe)

Front 224

what is a "rent" in a horse?

Back 224

a tear in the mesentery

Front 225

what is a major cause of SI incarceration in older horses?

Back 225

lipoma

Front 226

what is a cause of SI incarceration often seen after surgery, trauma, or foaling?

Back 226

mesenteric rent

Front 227

what site of SI incarceration is correlated with cribbing in horses?

Back 227

epiploic foramen

Front 228

what site of SI incarceration is associated with certain breeds such as warmblood breeds, standardbreds, Tennessee walking horses, and American saddlebreds? Why these breeds?

Back 228

- inguinal hernia
- seen in stallions because they have larger inguinal rings than other breeds of horses

Front 229

what are two anatomical ways that the horse may have an SI incarceration in the epiploic foramen?

Back 229

antegrade and retrograde

Front 230

what are four common sites of SI incarceration in the horse?

Back 230

1. epiploic foramen - older horses; cribbing
2. gastrosplenic ligament
3. inguinal hernia - stallions of breeds with large inguinal rings
4. mesodiverticular band - congenital, but seen in adult horses

Front 231

what is the anatomical pathogenesis of an inguinal hernia in the stallion?

Back 231

when they breed, they create a negative pressure with the cremaster muscle inside the scrotum. After breeding, this negative pressure sucks a bowel loop through the inguinal ring

Front 232

when repairing a scrotal hernia in the stallion, what should you also do?

Back 232

remove the testicle because it is probably damaged.

Front 233

what are the two types of scrotal hernias, what differentiates them, and what types do horses most commonly get? What type do humans most commonly get?

Back 233

- indirect: intestine goes through inguinal ring; horses get these
- direct: there is a defect NEXT TO the inguinal ring and the intestine goes into the scrotum through the defect; humans get these (ouch)

Front 234

in the horse, a hernia where only the side of a bowel loop protrudes through the neck is called what? What is a common site of this in the horse?

Back 234

- Richter's hernia
- umbilical hernia is a common site

Front 235

what is the mesodiverticular band and why is this structure important in the horse?

Back 235

it is an embryonic remnant and a common site for SI incarceration/strangulation

Front 236

what type of severe lesion can cut off the circulation to the entire small intestine in the horse?

Back 236

SI volvulus

Front 237

intussusception in the horse:
- what is the most common site?
- what age group?
- what most commonly causes this type of intussusception?

Back 237

- ileocecal
- most common in weanlings and yearlings
- related to tapeworm infestation

Front 238

what are five clinical signs of proximal (anterior) enteritis in the horse?

Back 238

1. fever
2. severe colic
3. voluminous gastric reflux
4. proximal small intestinal distention
5. ↑ protein in the peritoneal fluid

Front 239

what are four clinical signs of foal septicemia?

Back 239

1. severe colic
2. fever
3. mild to moderate abdominal distention
4. mild small intestinal distention on radiographs

Front 240

in what basic way is enteritis in the horse usually treated?

Back 240

medically, not surgically

Front 241

at what age does ascarid impaction most commonly occur in the horse?

Back 241

foals 3-6 months

Front 242

what are two reasons why a 3-6 month foal might have ascarid impaction?

Back 242

1. lack of preventative care
2. infestation + anthelmintic → obstruction

Front 243

what disease of the cecum in horses is associated with hospitalization and potentially related to anesthesia?

Back 243

cecal impaction

Front 244

what are two basic types of cecal impaction in the horse?

Back 244

1. dehydrated impaction: mass of food stuck in cecum
2. dysfunction - cecum filled with liquid due to cecal ileus

Front 245

what are two types of cecal intussusception in the horse?

Back 245

cecocecal and cecocolic

Front 246

in what age group of horses do we most commonly see cecal impaction?

Back 246

older horses; mean age 11-12 years

Front 247

what are three proposed risk factors for cecal impaction in horses?

Back 247

1. hospitalization
2. NSAIDs
3. anesthesia

Front 248

describe the timing of the onset of clinical signs of cecal impaction in horses

Back 248

can sneak up on you. Horses will be painful but show no clinical signs until the pain gets really bad

Front 249

what are four clinical signs of cecal impaction in horses?

Back 249

1. initially, depression and mild colic
2. pain increases as cecum distends
3. HR near normal until signs of shock
4. soft and scant feces

Front 250

how do you treat a cecal impaction that is caused by a firm mass (i.e. food bolus) in a horse?

Back 250

1. withhold food and water
2. parenteral hydration
3. oral laxatives (magnesium sulfate or psyllium)

Front 251

how do you treat a cecal impaction that is characterized by a massive distention (fluid consistency, not a firm mass) in a horse?

Back 251

1. withhold food and water
2. immediate surgery

Front 252

what is a common way to surgically treat a cecal impaction in the horse?

Back 252

an ileocolic bypass: anastomose the ileum with the colon directly; usually a good prognosis

Front 253

who is most susceptible to cecal rupture?

Back 253

broodmares

Front 254

what is the typical presentation of a cecal rupture in the horse?

Back 254

usually presents as peritonitis, rather than acute rupture

Front 255

what are three basic causes of obstruction of the large colon in horses?

Back 255

1. impaction
2. sand impaction
3. displacement

Front 256

what are the three most common types of large colon displacements in the horse?

Back 256

1. renosplenic (nephrosplenic)
2. right dorsal
3. retroflexion

Front 257

what are 5 clinical signs of large colon impaction in the horse?

Back 257

1. mild to moderate intermittent colic
2. mild dehydration
3. ↓ motility and pain when peristaltic sounds are heard
4. pelvic flexure filled with ingesta, which may be soft or hard
5. peritoneal fluid ± elevated protein

Front 258

what are two clinical signs in the horse that are normal in the horse with large colon impaction that are usually present with SI impaction?

Back 258

1. MM normal and normal CRT
2. gastric reflux is rare in LI, but common in SI

Front 259

how is non-surgical sand impaction treated in the horse?

Back 259

1. remove them from the source of sand
2. give psyllium
3. usually resolves on its own (i.e., they crap out the sand)

Front 260

how can you tell if you got blood from the spleen versus blood from a blood vessel? Why is this relevant in diseases of the large colon in horses?

Back 260

splenic blood has a very large PCV; left dorsal displacement/entrapment in the nephrosplenic ligament can result in a grossly enlarged spleen in the horse

Front 261

what type of displacement in the horse can result in a grossly enlarged spleen?

Back 261

left dorsal displacement/entrapment of the large colon in the nephrosplenic ligament

Front 262

what happens to the colon in a right dorsal displacement in the horse?

Back 262

colon moves to the right of the cecum

Front 263

what happens to the colon in left colon retroflexion displacement in the horse?

Back 263

the pelvic flexure ends up next to the stomach

Front 264

what are two types of large colon strangulation in the horse?

Back 264

1. large colon volvulus/torsion
2. incarceration (rare)

Front 265

in which three anatomical locations are the most common locations for large colon incarceration in the horse?

Back 265

1. nephrosplenic ligament
2. broad ligament
3. diaphragmatic hernia

Front 266

clinical signs of large colon volvulus in the horse:
- if it is 180°?
- if it is 360° or more?

Back 266

- 180° - colon edema
- 360° or more - infarction: severe, unrelenting pain, rapid progression of shock, MM are pale and cyanotic

Front 267

what are four changes of the abdominal cavity in a horse with large colon volvulus that is severe?

Back 267

1. gastric reflux
2. no motility; abdomen becomes bloated
3. massive distention of the colon (which sits across the pelvic inlet)
4. peritoneal fluid rapidly changes to have ↑ protein, RBC, and WBC

Front 268

which horses most commonly have large colon volvulus

Back 268

broodmares in late pregnancy and early lactation

Front 269

how long does it take for atresia coli to become clinically apparent in foals?

Back 269

24-48 hours (pain and distention)

Front 270

what infectious agent has been associated with impaction of the small colon in horses?

Back 270

Salmonella spp.

Front 271

what are three "liths" that cause SI obstruction in horses and the basic cause of each?

Back 271

1. enterolith: struvite - high Mg2+ in diet; foreign body nidus
2. fecalith: dense feed concentration
3. tricholith: hair concretion

Front 272

what are three pathological causes of SI strangulation in horses (i.e., other than the typical incarceration, intussusception, and volvulus)?

Back 272

1. intramural hematoma
2. lipoma
3. mesenteric trauma from foaling injury

Front 273

what disease of the horse SI has been associated with Salmonella, but no cause-effect relationship has been determined?

Back 273

small colon impaction

Front 274

when performing surgery for small colon impaction in the horse:
- how do you avoid inadvertent enterotomy
- how do you prevent new impaction after surgery?

Back 274

- lavage rectum to avoid enterotomy
- empty the cecum and large colon to prevent new impaction after surgery

Front 275

what type of diet may predispose a horse to struvite enteroliths?

Back 275

horses on hard water fed alfalfa hay

Front 276

what infectious agent is associated with thromboembolic colic in the horse?

Back 276

Strongylus vulgaris

Front 277

what is the most common site of Strongyle thromboembolic colic in the horse?

Back 277

cranial mesenteric artery and its branches

Front 278

what is a common cause of tympanic colic in newborn foals?

Back 278

meconium impaction

Front 279

how is meconium impaction prevented in newborn foals?

Back 279

enema

Front 280

what are six things that are treated with conservative/medical management to relieve intestinal obstruction in the horse (rather than go to surgery)?

Back 280

1. pain
2. distention/ischemia
3. dehydration
4. motility
5. inflammation
6. nutrition

Front 281

in intestinal obstructions in the horse, what are
- 2 causes of visceral pain?
- 3 causes of inflammatory pain?

Back 281

- visceral: intestinal distention; mesenteric stretch
- inflammatory: ischemia, inflammatory mediators, endotoxemia

Front 282

gastric decompression for relief of SI intestinal obstruction / proximal enteritis in the horse:
- when do you do it?
- how often?
- how is it done?

Back 282

- it is done right away, as part of the initial examination
- do it every 2-4 hours
- must initiate a siphon for fluids to be properly and completely collected

Front 283

what is a complication of repeated siphoning of the horse's stomach when treating obstruction/enteritis?

Back 283

3rd space fluid loss. Make sure of adequate hydration

Front 284

in the horse, what is the condition characterized by the cecum being distended with gas?

Back 284

cecal tympany

Front 285

cecal decompression in the horse:
- site of entry/landmarks
- what equipment is used?
- how do you ensure all the gas is out
- comment on the sterility needed
- how do you prevent bacterial contamination of the peritoneum?

Back 285

- right paralumbar fossa at the ventral border of the tuber coxae
- 15 cm needle or catheter
- have assistant maintain transrectal pressure to help remove all of the gas
- aseptic technique
- flush with saline during withdrawal of needle to help reduce bacteria entering the peritoneum

Front 286

what are six classes of drugs used as pain relief for colic in horses?

Back 286

1. tranquilizers
2. α2 agonists
3. narcotic agonists-antagonists
4. NSAIDs
5. lidocaine (IV)
6. spasmolytics

Front 287

how does xylazine relieve pain from colic in horses?

Back 287

causes intestinal relaxation and reduces spasms

Front 288

what is a popular spasmolytic drug used for colic in horses?

Back 288

Buscopan (N-butylscopolammonium bromide)

Front 289

Buscopan™ (N-butylscopolammonium bromide) for colic in horses:
- pharmacodynamics
- what is the effect
- duration of action

Back 289

- parasympatholytic that reduces GI smooth muscle contractions
- relaxes GI smooth muscle
- short acting (30 minutes)

Front 290

Buscopan™ (N-butylscopolammonium bromide) for colic in horses:
- side effects
- effect on gut sounds
- degree of analgesia

Back 290

- transient increased heart rate (parasympatholytic)
- decreased gut sounds
- no analgesia

Front 291

what are 5 responses of the horse's GI tract to prostaglandins, with regards to colic?

Back 291

1. potentiate pain
2. smooth muscle contraction (spasm)
3. smooth muscle relaxation (ileus)
4. vasoconstriction
5. initiate inflammation (↑ leukotrienes)

Front 292

what is the most effective NSAID for colic in horses?

Back 292

flunixin meglumine (Banamine™)

Front 293

why is phenylbutazone a poor choice for treating colic in the horse?

Back 293

because it is better for acute pain such as musculoskeletal pain

Front 294

why is flunixin meglumine (Banamine™) effective at relieving pain in horses with colic?

Back 294

because it targets visceral deep pain nociceptors

Front 295

besides flunixin, what are 2 other NSAIDs, which show a higher selectivity for COX-2, that are being used to treat colic in horses?

Back 295

1. Meloxicam
2. Firocoxib

Front 296

when treating a horse for colic, what is the typical fluid maintenance rate?

Back 296

1 liter/hour

Front 297

when administering fluids for systemic hydration in a horse with colic, what two electrolytes are important to monitor and replace?

Back 297

potassium and calcium

Front 298

what are the three most common laxatives to relieve large colon obstruction in horses?

Back 298

1. mineral oil - lubricant
2. magnesium sulfate (Epsom salts) - osmotic; increases water content of feces
3. ± dioctyl sodium succinate (DSS) - given with mineral oil to act as a surfactant

Front 299

after giving mineral oil to a horse with large bowel obstruction, how long should it take to pass, given there is not a blockage?

Back 299

12-18 hours

Front 300

explain "overhydration" to treat large colon obstruction in the horse?

Back 300

- administer 2-6x isotonic fluids (acetated ringer's)
- dilutes blood volume and they become hypoosmotic
- water bypasses kidney and dialyses into the peritoneum
- water absorbed by GI tract and dilutes feces

Front 301

indications for and how is enteral fluid therapy (i.e., by stomach tube) administered for large colon impaction? How long does impaction take to resolve?

Back 301

- usually indicated for chronic impactions
- 5-10 L fluid by stomach tube q 30 minutes
- impactions resolved in 2.5 days
(creates watery diarrhea)

Front 302

when treating a large colon impaction, what is the best type of fluid to administer to ensure maximum hydration of ingesta?

Back 302

balanced electrolyte solution

Front 303

Magnesium sulfate laxative effect in treating horses with large colon obstruction/impaction:
- effect on colon water content
- effect on fecal water content
- potential deleterious side-effect

Back 303

- minimal effect on colon water content
- increased fecal water
- potential for magnesium toxicity

Front 304

IV LRS solution - effect in treating horses with large colon obstruction/impaction:
- effect on colon water
- effect on PCV and TP

Back 304

- no effect on colon water
- minimal decrease in PCV or TP

Front 305

oral water - effect in treating horses with large colon obstruction/impaction:
- effect on colon water
- 3 potential deleterious side effects

Back 305

- no effect on colon water
- HYPONATREMIA, diarrhea, possible stomach or intestinal overload

Front 306

oral balanced electrolyte solution - effect in treating horses with large colon obstruction/impaction:
- effect on colon water
- effect on serum electrolytes
- effect on fecal water
- possible deleterious side effect

Back 306

- increases colon water
- no change in serum electrolytes
- no change in fecal water
- possible colon overload

Front 307

why is oral administration of balanced electrolyte solution superior to Epsom salt laxative, IV LRS administration, and oral water administration in the treatment of large colon obstruction/impaction in horses? (5)

Back 307

- increases colon water (laxative)
- does not increase fecal water (↓ diarrhea)
- does not affect serum electrolytes
- does not affect blood PCV or TP
- no toxic effects, as in Epsom salts (magnesium)

Front 308

comment on using prokinetics (parasympathomimetics) in the treatment of ileus in horses.

Back 308

- controversial efficacy; only used in severe cases

Front 309

what are five ways to treat ileus in horses?

Back 309

1. ± prokinetics (controversial)
2. block endotoxin
3. energy via IV feeding
4. decrease intestinal inflammation
5. enteral stimulation

Front 310

for treatment of ileus in horses with enteric stimulants such as metoclopramide, what type of neurological receptor is most important in initiating smooth muscle contraction?

Back 310

serotonin (5-HT4) receptors

Front 311

what is the most effective NSAID for treating PGE2-induced ileus in the horse?

Back 311

phenylbutazone

Front 312

what are two effects of reducing prostaglandins in the GI mucosa with NSAIDs in the treatment of ileus in the horse?

Back 312

1. reduces intestinal inflammation
2. blocks the effects of endotoxin

Front 313

what are three important electrolytes, which are typically reduced, to monitor and administer in the treatment of ileus in the horse?

Back 313

1. calcium
2. potassium
3. magnesium

Front 314

what drug is commonly used to relieve nephrosplenic entrapment of the large colon and how does it work? Efficacy?

Back 314

- phenylephrine
- contracts the spleen to allow bowel loop to return
- risky (hypertension and AV block) and negligible efficacy when used in conjunction with rolling the horse

Front 315

what is the gross pathological effect of transient SI ischemia in horses (e.g., using vasoconstrictors or having SI dilation)

Back 315

they produce fibrin as a result of ischemia and this can cause adhesions

Front 316

what three drugs are used to reduce inflammation and reduce the chance of fibrin adhesions in horses with SI impaction/dilation?

Back 316

1. flunixin
2. DMSO
3. lidocaine IV

Front 317

in what three ways is nutritional deprivation detrimental to the horse's GI tract?

Back 317

1. immunosuppression
2. ileus
3. villous atrophy

Front 318

post-surgery for GI problems, by which route of feeding a horse causes the least complication rates?

Back 318

enteral (versus parenteral)

Front 319

how does a hospitalized horse's daily energy requirement differ from when it is at home?

Back 319

decreases by 20-40%

Front 320

how many mL of water is in one swallow for the average horse?

Back 320

150 mL

Front 321

how long after large intestine surgery should you return a horse to:
- free choice water?
- free choice hay?

Back 321

- water right away
- free-choice hay after 24 hours

Front 322

what type of diet is commonly used in horses post-operatively following colic surgery?

Back 322

a low bulk diet; high energy, low bulk so that it is easy in the GI system

Front 323

what are five indications for parenteral nutrition in horses with colic?

Back 323

1. no oral intake in adult for 3 or more days
2. no oral intake in foal for 24 hours
3. obstruction of GI tract
4. impaired digestion
5. severe cachexia

Front 324

what % of horses with colic will need surgery?

Back 324

2-4%

Front 325

what are four indications for colic surgery in horses?

Back 325

1. rapid onset of acute pain
2. continuous pain
3. trauma to head or body
4. no response to analgesics

Front 326

what phrase is used with regards to making a timely decision for colic referral?

Back 326

"don't let the sun set on a colic"

Front 327

what are four important diagnostic techniques used when assessing a horse for colic surgery?

Back 327

1. RECTAL PALPATION
2. ULTRASOUND
3. peritoneal fluid analysis
4. hematology/chemistry

Front 328

what are the four most important criteria in determining whether a horse should have surgery for colic? What is #1 most important?

Back 328

#1 most important: RESPONSE TO TREATMENT - ANALGESIA!
2. degree of pain
3. rectal exam
4. motility on auscultation

Front 329

what are three clinical signs that would make you decide on surgery for colic?

Back 329

1. UNCONTROLLABLE PAIN
2. unexplained distention on rectal exam
3. no borborygmi

Front 330

what are two clinical signs, per rectum that indicate the horse has a rupture?

Back 330

1. granular surface to the peritoneum
2. gas in the abdomen

Front 331

when palpating PR a horse for colic, what side of the ass do you start on and in which direction do you move?

Back 331

start on left and move clockwise around abdomen

Front 332

what does SI obstruction feel like on a rectal exam in the horse?

Back 332

inflated bicycle tubes

Front 333

when a horse has colic, how can MM color help you determine whether or not to go to surgery?

Back 333

- red, yes
- cyanotic, ±
- pink, no
- pale, ±

Front 334

a horse is in the clinic for colic and painful. You give the horse detomidine and the pain subsides. After 30 minutes, the horse is wandering around the stall and paws a bit at the hay on the floor. What do you do?

Back 334

Detomidine is a very potent drug; the horse is still painful, go to surgery.

Front 335

a horse is in the clinic for colic and painful. You give the horse detomidine and the pain subsides. After a couple of hours, when the drug wears off, the pain comes back and after administration of more detomidine, the pain goes away again. What do you do?

Back 335

you are more likely to go to surgery than if the pain had not come back

Front 336

in the horse, what are normal peritoneal fluid values for:
- protein?
- WBC count?
- PMN:mononuclear cell ratio?
- RBC count?

Back 336

- protein = 0.7 - 1.5 g/dL
- WBC 200-3000 /μL
- ratio 2:1
- RBC rare

Front 337

when a horse has a bowel disease, the peritoneal fluid will often change (especially protein content). When a horse is showing clinical signs of colic, what do you do if the peritoneal fluid looks normal? Why?

Back 337

peritoneal fluid is normal in early stage of disease. Don't wait for peritoneal fluid to change. Increased protein in peritoneal fluid is correlated with a higher mortality, so if you wait, the horse could die. Base your decisions on other data.

Front 338

what are four contraindications to colic surgery in the horse?

Back 338

1. FEVER > 102° F
2. leukopenia or severe inflammatory leukogram
3. response to analgesics or fluids
4. progressive intestinal sounds