Term
| What are some common presenting complaints associated with oral disease in horses? |
|
Definition
| reduced feed intake (weight loss if chronic); slow/difficulty eating; dropping feed (quidding); ptyalism +/- bloody saliava; performance problems |
|
|
Term
| T/F reduced feed intake is NOT specific to primary GI disease |
|
Definition
TRUE
significant pain, endotoxemia, neurologic and renal disease can all cause reduced feed intake |
|
|
Term
| What physical exam/clin path finding is associated with anorexia in horses? |
|
Definition
| icterus and hyperbilirubinemia |
|
|
Term
| Which three infectious neurologic diseases can cause dysphagia and prehension problems in horses? |
|
Definition
rabies, botulism, tetanus
**always do a neuro exam (wear GLOVES) in horses with dysphagia |
|
|
Term
| Which method of restraining a horse for a full oral exam is preferred, the full mouth speculum or wedge/coil gag? |
|
Definition
full mouth speculum is preferred
** horse must be sedated for the speculum but gags do not reliably hold the mouth open and have risk of tooth fracture |
|
|
Term
| What are the four most common causes of stomatitis in the horse? |
|
Definition
| dental disease (ex. points on cheek teeth) causing mucosal trauma; coarse feed (traumatic stomatitis); vesicular stomatitis (REPORTABLE); slobbers (no oral lesion/ptyalism) |
|
|
Term
| What species are susceptible to vesicular stomatitis? |
|
Definition
horses, cattle and swine
** fever + oral mucosal vesicles -> coalescent erosions; endemic in SW USA |
|
|
Term
| What is the etiology and clinical presentation of slobbers? |
|
Definition
profuse salivation with no oral lesions
caused by SLAFRAMINE, a mycotoxin produced by fungus that infests red clover and alfalfa. No tx, self limiting (2-3 days) |
|
|
Term
| T/F The oropharynx is almost completely divided from the nasopharynx by the soft palate in horses |
|
Definition
TRUE
** nasopharynx can only be directly examined via endoscopy |
|
|
Term
| Abnormalities in what two body systems concurrently is highly suggestive of pharyngeal disease? |
|
Definition
|
|
Term
| T/F endoscopy is an excellent way to fully examine the oral cavity and can be performed under standing sedation |
|
Definition
FALSE
** horse should be under GENERAL ANESTHESIA when the endoscope is used in the oral cavity (to protect the equipment) |
|
|
Term
| Other than PE/palpation and endoscopy, what other diagnostic modality can be used to evaluate the pharynx in horses? |
|
Definition
| radiographs (lateral view) |
|
|
Term
| What age of horses is most susceptible to lymphoid hyperplasia? |
|
Definition
young (1-3 years)
** nodular protrusions of lymphoid follicles within the pharyngeal mucusa. If associated with viral/bacterial infection and phyaryngitis --> decreased performance, dysphagia, respiratory noise +/- mucopurulent nasal discharge |
|
|
Term
| What is the clinical significance of caps in an equine patient? |
|
Definition
| failure to shed deciduous teeth at the appropriate time can interfere with eruption or position of the permanent teeth |
|
|
Term
| Which aspect of the teeth of the maxilla and mandible respectively form points through normal wear in horses with normal dental conformation? |
|
Definition
points form on the lateral (BUCCAL) aspect of the upper arcade and on the medial (LINGUAL) aspect of the lower arcade
**occurs through normal wear because the upper arcades are wider than the lower arcades |
|
|
Term
| What is the clinical significance of dental malocclusions in horses? |
|
Definition
| impair normal chewing dynamics (side to side motion) --> result in progressively abnormal wear patterns |
|
|
Term
| How often should a horse have an oral exam? |
|
Definition
| once a year is ideal in adult horses; as often as every six months in young horses to address any abnormalities before they require extensive flotation (want to preserve the tooth material) |
|
|
Term
| What are some causes of primary esophageal obstruction or "choke" in horses? |
|
Definition
| poor quality feed; poor mastication; dehydration/lack of saliva; foreign body/gluttonous eater |
|
|
Term
| What are the four most common anatomic sites associated with primary esophageal obstruction/choke? |
|
Definition
| cranial cervical esophagus; thoracic inlet; cardia region; diaphragm |
|
|
Term
| What clinical signs are associated with choke/primary esophageal obstruction? |
|
Definition
| nasal reflux of saliva and feed material; anxiety and pain (muscle spasms); dehydration and electrolyte derangement (hyponatremia/kalemia due to salivary losses and anorexia) |
|
|
Term
| What are the two most definitive tests used to diagnose choke/esophageal obstruction? |
|
Definition
| endoscopy and radiography (survey and contrast) |
|
|
Term
| What are the two main therapies in the treatment of choke/esophageal obstruction? |
|
Definition
1. Rehydration (soften impaction, replace fluid deficits and electrolyte abnormalities)
2. Sedation/analgesics (relax horse and esophageal muscle) |
|
|
Term
| T/F horses treated for choke/esophageal obstruction should be NPO until the obstruction has passed and endoscopy has demonstrated mucosal integrity |
|
Definition
TRUE
once obstruction has passed feed soft mushy food |
|
|
Term
| What are three complications of choke/esophageal obstruction? |
|
Definition
1. stricture formation (mucosal trauma and ischemia -> circumferential lesions constrict as they heal)
2. Aspiration pneumonia (tx with broad spectrum antibiotics during and following an episode of choke)
3. esophageal dilation leading to megaesophagus or rupture (-> cellulitis and toxemia) |
|
|
Term
| What is the most common gastric disease affecting horses? |
|
Definition
|
|
Term
| What parasite colonizes the horse's stomach? |
|
Definition
| Gasterophilus spp. (horse bot fly) |
|
|
Term
| what is the most common gastric neoplasia in horses? |
|
Definition
gastric squamous cell carcinoma
** dx via endocsopy |
|
|
Term
| What are some clinical signs associated with gastric ulcers in foals? |
|
Definition
| hypersalivation and rolling on the back |
|
|
Term
| What anatomic region of the stomach is most susceptible to ulcer formation in adult horses? |
|
Definition
squamous mucosa especially adjacent to the margo plicatus (less cytoprotective mucus and bicarbonate)
**** foals however do get ulcerations of the glandular portion of the stomach, esp. in the region of the pylorus |
|
|
Term
| What three risk factors are highly associated with gastric ulcer syndrome in adult horses? |
|
Definition
training intensity; high grain diet; stress
*** pasture grazing has a gastro-protective effect |
|
|
Term
| T/F gastric ulcers in foals are usually secondary to generalized illnesses |
|
Definition
| TRUE 90% of foals in neonatal ICU have gastric ulcers |
|
|
Term
| Although the primary site of gastric ulceration is the squamous mucosa of the stomach, what two conditions are associated with ulceration of the glandular mucosa in adult horses? |
|
Definition
1. doudenal strictures that obstruct gastric outflow
2. NSAID toxicity (down regulated cytoprotective prostaglandins)
*** if using NSAIDs to reduce inflammation associated with primary GI disease (ex. reduce stricture formation following episode of choke with circumferential mucosal necrosis)systemic administration (IV) will reduce the negative topical effects |
|
|
Term
| What are some management principles that can reduce the incidence of equine gastric ulcer syndrome? |
|
Definition
| frequent feeding (esp. grazing), less grain (replace with corn oil for calories -> increases cytoprotective prostaglandins), alfalfa buffers stomach acids |
|
|
Term
| What is the most affective medication used in the treatment of equine gastric ulcer syndrome? |
|
Definition
omeprazole paste (proton pump inhibitor)
***use to tx gastric ulcers, or low-dose intermittently at times of highest risk (ex. showing, travel, on NSAIDs <- can also add misoprostol (PGE analogue) |
|
|
Term
| What is the most important element of treatment for gastroduodenal ulcer disease in foals (GDUD)? |
|
Definition
| Diagnose (endoscopy) and treat (omeprazole and sucralfate +/- misoprostol) EARLY before lesions progress to stricture (> 1week) and mechanical obstruction to gastric outflow <-- secondary to extensive mucosal necrosis |
|
|
Term
| What anatomic location of the GI tract is ALWAYS implicated equine cases of diarrhea? |
|
Definition
| COLON *** it is impossible to overwhelm the absorptive capacity of the normal equine colon (except neonatal foals) so adults really don't get secretory diarrhea |
|
|
Term
| What three infectious organisms cause diarrhea in foals? |
|
Definition
1. rotavirus (4-6months of age, malabsorptive diarrhea)
2. lawsonia intracellularis (weanlings, proliferative enteropathy -> edema/hypoprotinemia)
3. cryptosporidium spp. (malabsorptive, ZOONOTIC) |
|
|
Term
| What are three common non-infectious etiologies for diarrhea in horses/foals? |
|
Definition
foal heat diarrhea
NSAID toxicity (right dorsal colitis)
sand enteropathy |
|
|
Term
| Bloody diarrhea in horses is more suggestive of which two infectious organisms? |
|
Definition
| salmonella (also fetid odor) and clostridium |
|
|
Term
| What four pathologic processes can result in abdominal pain associated with the GI tract? |
|
Definition
1. distention of intestinal wall
2. stretching of the mesentary
3. inflammation of the intestinal wall
4. ischemia and spasm associated with muscularis layer of intestine |
|
|
Term
| T/F blind stick abdominocentesis should NOT be performed in horses with abdominal distention |
|
Definition
| True, increased risk of entering the lumen of the bowel -> peritonitis ** use ultrasound to locate abdominal fluid |
|
|
Term
| T/F normal peritoneal fluid on belly tap can be used to rule out strangulating lesions/ischemic gut |
|
Definition
FALSE
***normal adult horse WBC:
5,000-10,000/uL
normal protein <2g/dl |
|
|
Term
| What two issues are the most important risk factors associated with colic in horses? |
|
Definition
DIET
Amount/type of excercise |
|
|
Term
| Postpartum mares are at risk for what type of colic? |
|
Definition
|
|
Term
| What are six indications for refering a colic? |
|
Definition
1. non-responsive to pain medication
2. heart rate is persistently >48bpm
3. presence of gastric reflux (SI lesion)
4. increased abdominal distention
5. abnormal mentation
6. abnormal findings on rectal palpation (surgery is generally indicated) |
|
|
Term
| What is the only situation where percutaneous trocharization is indicated in equine colic? |
|
Definition
| cecal/large colon tympany (gas distention) |
|
|
Term
| The left side of the maxilla is associated with which quadrant in the triadan system? |
|
Definition
|
|
Term
| The right side of the maxilla is associated with which quadrant in the triadan system? |
|
Definition
|
|
Term
| The left side of the mandible is associated with which quadrant in the triadan system? |
|
Definition
|
|
Term
| The right side of the mandible is associated with which quadrant in the triadan system? |
|
Definition
|
|
Term
| How is the camelid stomach different from the ruminant stomach? What are the similarities? |
|
Definition
camelids have a 3 chambered stomach rather than 4 (ruminants) and are more efficient at VFA production than ruminants (adapted to high altitude poor quality forage environment)
however; both species have similar protozoal and bacterial organisms colonizing their stomach |
|
|
Term
| What teeth are synonymous with fighting teeth in camelids? |
|
Definition
canines (upper and lower)
+ 3rd maxillary incisiors in intact males
***cammelids do not have any other upper incisiors, they have a dental pad |
|
|
Term
| Why should venipuncture should always be performed on the right hand side of the neck in camelids? |
|
Definition
| the esophagus is very closely associated with the jugular vein on the left side of the neck, ALWAYS collect blood from the right jugular in camelids |
|
|
Term
| What type of muscle composes the camelid esophagus? |
|
Definition
|
|
Term
| What esophageal problem is more common in camelids than horses? |
|
Definition
megaesophagus
***dx via survey radiographs (dilated esophagus +/- aspiration pneumonia) and less commonly endoscopy (very stressful for this species) |
|
|
Term
| T/F contrast radiography of a cria with a vascular ring anomaly will show a dilated esophagus proximal AND distal to the region of stricture |
|
Definition
TRUE
camelids reguritate their cud so the stricture will cause dilation proximal to the stricture due to ingested feed, and distal due to impacted cud |
|
|
Term
| What is the prognosis for camelids with idiopathic megaesophagus |
|
Definition
prognosis is poor unless secondary to an underlying disease that can be directly treated.
***can manage with antibiotics (due to risk of aspiration pneumonia), small particle easily digestible feed trying either elevated or lowered feeding positions, drug therapy is questionably effective due to lack of pharmacokineitc understanding in this species |
|
|
Term
| What eletrolyte derangement is most commonly associated with obstruction near the pylorus in camelids? |
|
Definition
| hypochloremia --> metabolic alkalosis |
|
|
Term
| What region of the camelid stomach is most prone to ulceration? |
|
Definition
| the distal 1/5th of C3 (only location where acid is secreted) |
|
|
Term
| What is the most frequent cause of obstruction in camelids? In crias? |
|
Definition
bezoars (esp. C3 and spiral colon) in adults
hairballs in crias |
|
|
Term
| T/F camelids are relatively resistant to grain overload |
|
Definition
|
|
Term
| What are three important infectious causes of diarrhea in camelids? |
|
Definition
| Coccidiosis, coronavirus, BVD |
|
|
Term
| What are two anatomic features of the camelid liver? |
|
Definition
| liver is located completely on the right side of the animal, camelids (and horses) have NO gallbladder |
|
|
Term
| Why are camelids especially susceptible to developing hepatic lipidosis? |
|
Definition
| camelids are naturally relatively insulin resistant and quickly develop marked hyperglycemia when stressed |
|
|
Term
| What is the etiologic agent and clinical consequences associated with alpaca fever? |
|
Definition
ingestion or inhalation of Strep zooepidemicus --> septic peritonitis +/- pleuritis in young and pregnant females
**dx via cytology of effusion (chains of gram + cocci) and tx early with IV penicillin |
|
|
Term
| What is the only secretory component of the ruminant stomach? |
|
Definition
|
|
Term
| What physiologic processes occur in the rumen? |
|
Definition
| physical breakdown and fermentation of feed, VFA absorption |
|
|
Term
| How does diet affect the mucosal lining of the rumen? |
|
Definition
forage based diet --> smaller rumena papillae (less VFA production)
high CHO diets --> high levels of VFAs produced -->larger more developed papillae |
|
|
Term
| What type of fermentation occurs in the rumen and what components of feed materials are being broken down? |
|
Definition
| anaerobic fermenetation (via bacteria/protozoa/fungi) --> break down of cellulose and lignin |
|
|
Term
| What biochemical process is utilized in ruminants to burn VFAs for energy? |
|
Definition
|
|
Term
| Other than VFAs what is the other major byproduct of the anaerobic fermentation that occurs within the rumen? |
|
Definition
|
|
Term
| What type of diet results in optimal GI function in ruminants? |
|
Definition
|
|
Term
| What is the normal range of rumen pH? |
|
Definition
|
|
Term
| What two major contraction patterns are associated with normal rumen motility? |
|
Definition
primary contraction cycle --> mixing of ingesta to maintain normal fermentation and stratification of rumen contents
secondary contraction cycle --> occurs secondary to gas distention of the dorsal aspect of the rumen -> cardia relaxes and cranial wave of contraction pushed gas into the esophagus -> eructation |
|
|
Term
| What central and peripheral innervation is involved in maintaining rumen motility? |
|
Definition
| vagus nerves transmit motor and sensory info to and from the gastric centers in the medulla oblongata |
|
|
Term
| What two physical phenomena increase rumen motility? |
|
Definition
eating (ie. presence of feed in mouth, esophagus and forestomach)
mild-moderate distention of the rumen and abomasum |
|
|
Term
| What decreases rumen motility? |
|
Definition
severe distention
very low pH (normal is 5.5-7)
very high VFA concentrations
toxemia, systemic dz, CNS dz --> depression at the level of the medulla oblongata |
|
|
Term
| What is the normal stratification pattern of ingesta in the rumen? |
|
Definition
dorsal gas cap
floating mat of coarse fibrous feed
fine feed particles suspended in fluid |
|
|
Term
| What distinctive shape on PE is associated with rumen over-fill? |
|
Definition
papple abdomen
normally shaped like a pear, with rumen distention left dorsal side fills out like an apple
***most commonly associated with vagal indigestion (secondary to hardware dz) |
|
|
Term
| What physical abnormalities must occur to produce a ping following percusion? |
|
Definition
| fluid/gas interface within a pressurized viscus close to the body wall <-- can be helpful for LOCALIZING problems in the GI |
|
|
Term
| What two tests can be used to identify cranioventral abdominal pain in cattle? |
|
Definition
withers pinch (ie. scootch test) -> should normally move away from this stimulus
xiphoid pressure test --> should normally not be bothered by this
***positive responses are common in cases of hardware dz and perforated abomasal ulcers |
|
|
Term
| T/F rectal palaption is indicated in ruminants where there is suspicion of ANY GI/abdominal disorder |
|
Definition
TRUE
***if suspecting ulcers test feces for occult blood BEFORE doing the rectal exam |
|
|
Term
| rumen fluid analysis can be used to assess the status of what four elements of GI physiology in cattle? |
|
Definition
analyze rumen fluid to assess pH, status of fermentation (new methylene blue reduction test and sedimentation test), microbial flora, and abomasal outflow
***avoid salivary contamination (will artifactually elevate pH) |
|
|
Term
| Which element of rumen microflora is most sensitive to changes in rumen pH? |
|
Definition
| protozoa (esp. large species) |
|
|
Term
| What chloride concentration >30mEq/L are associated with what type of GI lesions in cattle? |
|
Definition
obstruction at the pylorus or proximal small intestine
***impaired abomasal outflow results in backwats of HCl into the rumen (lowers the pH and increases the chloride) |
|
|
Term
| Why might you consider taking foot radiographs in a horse presenting with diarrhea? |
|
Definition
| baseline rads to monitor any development or progression of laminitis as horses with endotoxemia are at increased risk |
|
|
Term
| Bloody diarrhea in horses is highly suggestive of what two etiologies? |
|
Definition
| clostridium and salmonella (also fetid odor) |
|
|
Term
| T/F fecal culture is an important tool for diagnosis of specific bacterial etiologies of diarrhea in the horse |
|
Definition
| FALSE there is too much normal enteric flora for fecal culture to be valuable, must run tests specific to organisms suspected (ex. salmonella culture, clostridium/rotavirus ELISA, crypto IHC etc.) |
|
|
Term
| Other than biosecurity, what is the main reason horses with diarrhea require hospitalization? |
|
Definition
| FLUID THERAPY **often requires aggressive tx with crystalloids and colloids to maintain hydration and oncotic pressure (secondary to intestinal albumin loss) |
|
|
Term
| What probiotic yeast can be used to reduce duration and severity of clinical signs of acute enterocolitis in horses (when combined with standard tx)? |
|
Definition
|
|
Term
| What clinical signs and course are associated with foal heat diarrhea? |
|
Definition
mild diarrhea and no systemic illness in foals 5-14 days of age, no tx- self limiting
*** most likely due to developmental changes in the intestinal epithelium |
|
|
Term
| What is the most common cause of infectious diarrhea in foals 4-6 months of age? |
|
Definition
rotavirus
***fecal oral transmission, many adult horses are asymptomatic shedders --> high environmental virus load |
|
|
Term
| What is the epidemiologic presentation and diagnostic test used to diagnose roatvirus in foals? |
|
Definition
mild to severe diarrhea, multiple individuals affected (foals 4-6 months)
Dx with fecal ELISA |
|
|
Term
| What is the pathophysiology of rotavirus diarrhea in foals (4-6 months)? |
|
Definition
virus has a predilection for the SI villi -> maldigestion and malabsorption --> osmotic diarrhea
virus also destroys lactase (normally at the brushboarder) -> lactose intolerance |
|
|
Term
| What treatment, control/preventative measures should be adopted in the case of rotavirus diarrhea in foals (4-6 months)? |
|
Definition
ISOLATION (extensive viral shedding in feces)
supplement with lactase, GI protectants/adsorbents, omeprazole (PPI, sick foals are at high risk of developing gastric ulcers <-- glandular pyloric)
***vaccinate dams in late gestation on endemic farms (antibodies transferred to foal via colostrum) |
|
|
Term
| What two common causes of diarrhea in horses are zoonotic? |
|
Definition
| cryptosporidiosis and salmonellosis |
|
|
Term
| How do you diagnose cryptosporidium in a horse with diarrhea? |
|
Definition
| direct fecal smear +/- histopathology of mucosal biopsy |
|
|
Term
| T/F there is no specific treatment for cryptosporidiosis |
|
Definition
TRUE
**manage with supportive nursing care and isolation (extremely contagious and ZOONOTIC) |
|
|
Term
| What is the pathophysiology of diarrhea caused by Lawsonia intracellularis (weanlings)? |
|
Definition
| proliferative enteropathy --> malabsorption and protein loosing enteropathy -> weight loss, edema +/- diarrhea |
|
|
Term
| What age of horses are most suceptible to diarrhea cause by Lawsonia intracellularis? |
|
Definition
weanlings
** disease in adult horses in rare |
|
|
Term
| How do you diagnose and treat diarrhea caused by lawsonia interacellularis in horses (weanlings)? |
|
Definition
Dx: thickened SI wall on ultrasound (>3mm), fecal PCR, marked hypoprotinemia on serum chemistry
tx: IV oxytetracycline (decreased oral bioavilability due to malabsoptive dz) and hetastarch/plasma transfusion (maintain oncotic pressure in the face of protein loosing enteropathy) |
|
|
Term
| What organisms is commonly implicated in cases of nosocomial infection in horses? |
|
Definition
| Salmonella (increased shedding in sick/stressed horses) |
|
|
Term
| What is the most common serotype of slamonella that causes diarrhea in horses? |
|
Definition
|
|
Term
| T/F horses infected with salmonella will shed the organism for the rest of their lives |
|
Definition
FALSE
shedding is usually transient and horses are less likely to remain chronic carriers than cattle |
|
|
Term
| What is the pathophysiology associated with salmonellosis in horses (any age)? |
|
Definition
| gram negative organism replicates in enterocytes -> release of endotoxins causes intestinal hypersecretion -> bacteremia and seeding of other organs is common |
|
|
Term
| What diagnostic test is necessary to rule out salmonellosis as the cause of diarrhea in horses (any age)? |
|
Definition
five negative consecutive fecal cultures
also fecal PCR is available |
|
|
Term
| What necropsy findings are consistent with salmonellosis? |
|
Definition
severe enterocolitis with mucosal ulceration and necrosis +/- infarcts in gut and other organs
definitive Dx: cultures from enteric lumen and wall +/- other body tissues |
|
|
Term
| What two species are most commonly implicated in cases of clostridial enterocolitis? |
|
Definition
c. difficile and perfringens
<-- these are part of the normal gut flora, overgrowth and subsequent diarrhea usually due to disruption of normal GI microenvironment |
|
|
Term
| How to you diagnose and treat clostridial enterocolitis in horses (any age, acute diarrhea)? |
|
Definition
Dx via fecal ELISA (enterotoxin)
Tx with ORAL metronidazole (want to obtain high concentrations of antibiotics within the gut LUMEN) |
|
|
Term
| What clinical presentation is associated with the syndrome of Colitis X in horses? |
|
Definition
| severe peracute necrotizing enterocolitis with high mortality |
|
|
Term
| What is the causative agent of potomac horse fever? |
|
Definition
|
|
Term
| What epidemiologic features are associated with diarrhea in horses secondary to potomic horse fever (N. risticii) |
|
Definition
occurs in the summer/autumn in MN in animals with exposure to bodies of water (life cycle involves aquadic snails and insects <-- ingested by the horse)
1 or more horses affected (not contagious from horse to horse) |
|
|
Term
| How do you diagnose and treat potomac horse fever? |
|
Definition
Dx: fecal or blood PCR <- false negatives possible
Tx: IV oxytetracycline (only in well hydrated animals otherwise nephrotoxic)
vaccination reduces severity of clinical course and should be considered in endemic regions |
|
|
Term
| Other than diarrhea what two clinical signs/disease processes are often associated with potomac horse fever? |
|
Definition
laminitis
fever and limb edema |
|
|
Term
| What is the most common anatomic site for lesions associated with NSAID toxicity in horses? |
|
Definition
| ulceration of right dorsal colon (Dx on ultrasound, thickened wall >5mm) +/- concurrent oral or gastric ulcers |
|
|
Term
| What constellation of clinical signs is associated with chronic diarrhea in horses? |
|
Definition
weight loss, hypoportinemia, ventral edema
**often secondary to inflammatory/infiltrative bowel diseases |
|
|
Term
| What diagnostic tests can be used if inflammatory/infiltrative GI disease is suspected in horses? |
|
Definition
glucose/xylose absorption tests --> inadequate with malabsorptive diseases
rectal mucosal biopsy
thickened gut wall on ultrasound |
|
|
Term
| What is the treatment of choice for IBD in horses? |
|
Definition
|
|
Term
| What is the definition of peritonitis? |
|
Definition
| inflammation of the mesothelial lining of the peritoneal cavity |
|
|
Term
| Most cases of equine peritonitis are classified as: |
|
Definition
| acute, diffuse and septic |
|
|
Term
| Hematogenous peritonitis is most common in what two groups of horses? |
|
Definition
| foals and immunocompromised animals |
|
|
Term
| What is the most common etiology of peritonitis in adult horses? |
|
Definition
Gastrointestinal leakage
*** secondary to obstruction/strangulation, parasitism, perforated ulcers, iatrogenic (rectal palpation, enterocentesis/biopsy, trocarization) |
|
|
Term
| What two clinical signs are most reliably present in cases of peritonitis in the horse? |
|
Definition
|
|
Term
| What findings on abdominocentesis are consistent with peritonitis in the horse? |
|
Definition
increased WBC and TP (normal is <5000/uL WBC, <2.5g/dl TP)
change in color (normal is clear, light yellow)
+/- lactate (devitalized gut) and gram stain/culture (guide antibiotic selection <--- so collect fluid prior to administering any antibiotics) |
|
|
Term
| What impressions on rectal palpation can be associated with diffuse peritonitis? |
|
Definition
| serosal surfaces feel sticky/rough on rectal palpation |
|
|
Term
| How does septic peritonitis differ from non-septic peritonitis on abdominal ultrasound? |
|
Definition
| Both are associated with increased volume of free fluid in the abdomen; however, non-septic peritonitis is associated with hypoechoic fluid while septic peritonitis is associated with increased fluid echogenicity due to increased numbers of WBC and fibrin strands |
|
|
Term
| T/F a negative culture of peritoneal fluid rules out septic peritonitis in the horse |
|
Definition
FALSE, even with a negative culture elevated WBC (esp. neutrophils) and TP in peritoneal fluid in conjunction with systemic illness is consistent with septic peritonitis in the horse
*** Tx with BROAD SPECTRUM antibiotics (typically penicillin + gentamicin + metronidazole while awaiting further diagnostics) |
|
|
Term
| When should you initiate antibiotic therapy in a horse with suspected septic peritonitis? |
|
Definition
begin antibiotic tx as soon as peritoneal fluid has been collected (if you do this after starting antibiotics --> false negative fluid culture)
**** penicillin + gentamicin + metronidazole IV |
|
|
Term
| Which technique is more effective, surgical or standing peritoneal lavage? |
|
Definition
| surgical is more effective but complete lavage of the equine abdomen is virtually impossible |
|
|
Term
| What medications may reduce adhesion formation in horses following an episode of peritonitis? |
|
Definition
| flunixin and heparin may reduce adhesion formation in horses |
|
|
Term
| What species of bacteria is associated with the best prognosis in cases of septic peritonitis in horses? |
|
Definition
Actinobacillus equuli
** marked inflammation on CBC and peritoneal fluid cytology; however, fibrous adhesions are rare and prognosis for full recovery is excellent |
|
|
Term
| What is the prognosis for a horse with septic peritonitis following GI rupture? |
|
Definition
|
|
Term
| What is the etiology of photosensitization secondary to hepatic disease in horses? |
|
Definition
Phyloerythrin (from chlorophyll) is normally metabolized by the liver, in cases of hepatic dysfunction phyloerythrin deposits in the skin and incites oxidative damage following UV exposure
** photosensitization can also be the result of contact with photodynamic plants |
|
|
Term
| T/F edema and ascites are common in equine patients with liver disease |
|
Definition
FALSE
albumin is rarely low in equine patients with liver disease (albumin has a really long half life in horses) |
|
|
Term
| Elevations of what two enzymes on serum chemistry are indicative of hepatocellular necrosis in horses? |
|
Definition
SDH (liver specific, short half life)
AST (not liver specific, long half life) |
|
|
Term
| T/F elevations in SDH, AST, GGT, and/or ALP all indicate some degree of decreased liver function |
|
Definition
FALSE
elevations in these enzymes suggest either hepatocellular necrosis (SDH/AST) or cholestasis (GGT/ALP)
***assess liver function via bilirubin, ammonia, BUN, glucose, secondary coagulation and bile acids |
|
|
Term
| The liver can maintain normal synthetic output unless what percent is compromised/damaged? |
|
Definition
| >70% of the liver must be compromised before any changes in function are appreciable |
|
|
Term
| What test is the most sensitive indicator of liver function? |
|
Definition
Bile acids (if liver function is compromised bile acids will be high)
*** because horses don't have a gallbladder no need to take a postprandial sample |
|
|
Term
| What is often the only way to identify the etiology of liver disease in horses? |
|
Definition
| liver biopsy <-- always ultrasound guided |
|
|
Term
| What antibiotics are warranted if cholangitis/hepatitis is suspected in an equine patient? |
|
Definition
| TMS and enrofloxacin <-- both are excreted in the bile |
|
|
Term
| What is the pathophysiology associated with Tyzzer's disease in young foals (7-42 days)? |
|
Definition
Clostridium piliforme shed in the feces of adult horses (normal colonic flora) contaminates pastures --> foals ingest the bacteria and they did not recieve colostral antibodies (specific to this organism? or FTP) they develop acute fatal hepatic necrosis
**most common in foals of mares new to pasture |
|
|
Term
| How do you diagnose Tyzzer's disease in foals? |
|
Definition
diagnosis is made at necropsy, histopathology of the liver reveals filamentous intracellular organisms
**** very difficult to culture |
|
|
Term
| What is the etiology of Theiler's disease in adult horses? |
|
Definition
acute hepatic necrosis usually 4-10 weeks after receiving products containing equine serum
**** centrilobular to midzonal hepatocellular necrosis and hemorrhage on histopath of liver biopsy |
|
|
Term
| What toxins are associated with hepatic necrosis in horses? |
|
Definition
pyrrolizadine alkaloids (toxic effects are cumulative),
alsike clover (acute exposure causes primary photosensitivity, chronic ingestion causes biliary hyperplasia, perilobular fibrosis and secondary photosensitivity)
aflotoxin |
|
|
Term
| What is the pathophysiology of pyrrolizadine alkaloid hepatotoxicity in horses? |
|
Definition
pyrrolizidine alkaloids are ingested and metabolized to pyrroles in the liver --> antimitotic effect on hepatocytes results in the formation of megalocytes --> megalocytes die and are replaced with fibrosis
**effects are cumulative |
|
|
Term
| What histopathologic findings are consistent with pyrrolizadine alkaloid toxicity on liver biopsy histopathology? |
|
Definition
| periportal fibrosis, megalocytes, and biliary hyperplasia |
|
|
Term
| What physical exam finding is associated with cholangiohepatitis in horses? |
|
Definition
| exfoliative dermatitis of the coronary band |
|
|
Term
| What laboratory and histopath findings are consistent with the diagnosis of cholangiohepatitis in horses? |
|
Definition
Leukocytosis, hyperprotinemia, elevated GGT/ALP
periportal inflammation, gram negative organisms on tissue culture |
|
|
Term
| What is the ultrasonographic appearance and prognosis associated with choleoliths in horses? |
|
Definition
| present as hyperechoic massess with shadowing on ultrasound, very poor prognosis |
|
|
Term
| What is the definition of shock? |
|
Definition
| profound and widespread derangement of effective tissue perfusion leading to initially reversible, and then irreversible cellular injury |
|
|
Term
| What four physiologic requirements are necessary for effective circulation? |
|
Definition
1. blood maintained in fluid state
2. adequate oncotic pressure and regulation of fluid balances
3. patent blood vessels with appropriate vascular tone (regulated by sympathetic innervation)
4. functional pump (ie. the heart) |
|
|
