Smith 5 - 32 Eq GI Flashcards
E - excess salivation results in what derangements
hypoCl, hypoNa, hypoK
type I gastric impaction
- feed
- no increase in stomach size
type II gastric impaction
- feed
- increased stomach size
type III gastric impaction
phytobezoar or persimmons
E - MODS
multi organ dysfunction syndrome
-dysfunction of 2 or more organs in severe sepsis
E - ulcerative duodenitis
- acid related
- foals w gastric dz too
- CS more severe
E - mechanisms of increased secretion in DPJ
1) passive transmucosal exudation secondary to mucosal / submucosal inflammation –> protein rich fluid
2) active secretion caused by increased cyclic nucleotides –> low protein, high electrolyte fluid
equine proliferative enteropathy
lawsonia
- fever, lethargy, edema, D+, colic, weight loss
- weanlings - young
- invasion of crypt cells in ileum causes excess mitotic division and hyperplasia
- lesions distal jej and ileum
- tx: macrolides + rifampin, chloro, oxytet, doxy
Eq lymphosarcoma
usually SI, diagnosed on ab tap cytology
E - what can cause diarrhea without inflammation
CHF or cirrhotic liver disease - increased intestinal hydrostatic pressure
E - effector cell of acute colitis
neutrophil
E - which salmonella is most common
s. enterica typhimurium
E - gold standard PHF diagnosis
qPCR of whole blood to detect N. risticii in leukocytes
E - cause of abx-associated D+
c. diff
- toxin A and B
E - c. diff toxin A
- secretory and cytotoxic
- activates immune cells to release pro inflammatory cytokines and mediators
- works w NT substance P
- effects mediated through direct effect on intestinal cells + enteric nervous system
E - c. diff toxin B
secretory?
little relevance
E - c. diff Tx
metro, vancomycin
E - coronavirus enteritis
fever, lethargy, colic, and D+
- usually lasts a week and self limiting
- can cause acute necrotizing neutrophilic SI inflammation
**hyperammonemia
E - cantharidin effects
- mucosal ulceration
- cystitis, nephrosis, myocarditis
- hypoCa and Mg
- pupd, diffuse D+, thumps, can acutely die
E - features of grain overload
hyperlactatemia, metabolic acidosis, sepsis
E - actinobacillus equuli peritonitis
mild to mod colic, lethargy, elevated HR/RR
- marked elevation in ab tap protein and cell count
- responds well to penicillin
- does not cause sepsis
E - what causes post operative ileus
inflammation in the muscularis
bethanecol
- prokinetic
- used because it increases contractility ex: delayed gastric emptying
- increases strength and duration of cecum and RVC
neostigmine
inhibits cholinesterase –> increases receptor levels of ach
metoclopramide
- moderate partial 5-HT4 agonist
- moderate 5-ht3 antagonist
- antagonist of dopamine 1 and 2 receptors
–> 5HT effects thought to be the most prokinetic
- facilitates ach release and smooth muscle contraction
- can cross BBB and cause seizure
domperidone
- competitive agonist at dopamine 2 receptors
- these are inhibitory receptors
- prokinetic in humans
erythromycin lactobionate
- direct motion receptor agonist that works directly on smooth muscle cells
- hastens cecal emptying
combining two NSAIDs
- prolongs pharmacological effects
- increases toxicity
- same toxicity as giving a double dose of one
Ptyalism DDX
Dysphagia: esophageal obstruction, oral foreign body, rabies, neurological disease
Toxicity: heavy metals, parasympathomimetics, cholinesterase insecticides (organophosphates and carbamates), cholinergic agonists – *slaframine from red clover contaminated with rhizoctonia/rhix
Ranula
salivary mucocele that occurs secondary to obstruction of the sublingual salivary duct
treatment is to create a fistula into the oral cavity
most frequently reported oral tumor in the horse
Oropharyngeal squamous cell carcinoma
persistent right fourth aortic arch
can cause congenital obstruction of the esophagus
constriction by the ligamentum arteriosum extending between the right aorta and the left pulmonary artery with secondary dilation cranial to the obstruction
rebound secretory response
o The use of proton pump inhibitors (PPIs) increases gastric pH
o Increased gastric pH increases gastrin secretion from the G-cells in an attempt to lower gastric pH
o Enhanced gastrin secretion causes proliferation of enterochromaffin-like (ECL) cells
o Once proton pump inhibitors (PPIs) are discontinued, this leads to massive HCl secretion
o This is the theory behind weaning off of omeprazole
competitively blocks the H2 receptor on the basolateral surface of the parietal cell
ranitidine
Functional secretion of chloride in the crypt cell is caused by
an increase in cAMP.
This also leads to kinases being secreted that block sodium chloride absorptive process in the mucosal cells
DPJ Prognosis
TP > 3.5g/dL
anion gap > 15mEq/L
both associated with poorer prognosis
Excessive fluid and electrolyte secretion into the small intestine, and, consequently, large volumes of enterogastric fluid.
Serositis is a consistent finding, characterized by bright red to dark petechial and ecchymotic hemorrhages on the serosal surface.
DPJ
Suspicion based on clinical signs, hypoalbuminemia, thickening of segments of small intestinal wall observed on ultrasound, positive serology, and molecular detection in feces.
Mechanism of enteritis involves invasion of the proliferating crypt cells in the ileum, causing extensive mitotic division and severe hyperplasia.
Mucosa becomes grossly thickened and develops corrugated appearance. Limited brush border leads to limited absorptive capacity causing the weight loss and hypoproteinemia usually observed.
Generally manifested in foals less than 1 year of age between the months of August and February.
EPE / Lawsonia
Most consistent lab finding with lawsonia / EPE
TP < 5g/dL
albumin < 2
Dx testing for lawsonia
Real time PCR has been shown to best sensitivity.
Immunoperoxidase monolayer assay is the most specific when determining presence of antibodies in adult horses with EPE
Dx of equine septic peritonitis
AB tap Glucose < 30mg/dl
OR AB glu 50mg/dl LESS than the systemic glucose
OR AB glu < 50% of systemic
+ ab pH < 7.3
most common anaerobe in equine septic peritonitis
bacteroides fragilis
actinobacillus peritonitis
Infection is thought to be secondary to GI translocation or strongyles migration
o Horses commonly present with signs of colic +/- fever. A chronic form is possible and commonly presents with weight loss.
o Peritoneal WBC are usually markedly elevated (>100,000/ul) with an elevated peritoneal TP.
o Gram – rods commonly visible on smear of peritoneal fluid and bacterial culture reveals pure growth of A. equuli.
o These hoses respond well to penicillin/gentamicin and have a good prognosis. Antibiotics should be continued for 7 days following peritoneal fluid returning to normal.
hemoperitoneum
Diagnosis is a characteristic ‘smoke swirling’ sign in the abdomen; confirmed by a peritoneal PCV >5%, elevated TP and gross appearance
Tx is stabilization; abx ARE indicated
cisapride
2nd generation benzamide.
Acts at 5-HT4 and 5-HT3 to increase ACh.
Potential cardiac side effects. Not available in the USA
most commonly isolated serotype of salmonella in equine diarrhea
typhimurium
risk factors for small colon disease
minis
arabians
ponies
older > 15years
mares
