Equine Acute And Chronic Diarrhoea In Adults Flashcards
- How much fluid enters the horse GI tract in 24hrs? - where is it reabsorbed?
- Origin of diarrhoea in the adult horse?
- Origin of diarrhoea in foals?
- 100L - LI.
- LI.
- SI or LI.
Mechanisms of diarrhoea in the adult horse.
Bowel inflammation - colitis.
Inflammation causes diarrhoea mainly via:
- malabsorption e.g. due to damage.
- increased secretion.
- decreased transmit time (abnormal motility).
Diagnostic approach - history taking in the adult horse?
Age.
Acute or chronic.
Dietary change?
Deworming history.
Others affected?
Recent NSAID or ABX use/abuse.
Diagnostic approach - differentials.
Genetic.
Infectious - bacteria, fungi, virus, Protozoa, parasites.
Inflammation.
Neurological.
Autoimmune.
Nutritional.
Developmental.
Degenerative.
Trauma.
HOrmonal
Neoplastic.
Iatrogenic.
Idiopathic.
Cardiovascular.
Chemical or toxic.
Differentials for chronic diarrhoea.
Genetic (granulomatous bowel disease).
Infectious - bacteria (chronic salmonellosis), parasitic (Strongyloides, cyathostomiasis).
Inflammatory - sand.
Auto immune - inflammatory and granulomatous bowel diseases.
Neoplasia (lymphoma most common).
Chemical and toxic / iatrogenic - NSAID use/abuse (right dorsal colitis), antibiotic induced.
- NB some non-GI causes e.g. some liver disease.
Differentials for acute diarrhoea.
Infectious - bacteria (salmonella, clostridia (toxin), rhodococcus (foal).
- parasitic (cyathostomiasis).
- viral (rotavirus).
Nutritional - sudden diet change (shouldn’t be sick).
Idiopathic - most acute colitis.
Chemical and toxic / iatrogenic - NSAID use/abuse (right dorsal colitis), antibiotic-induced.
NB some non-GI causes e.g. some liver disease.
Assessing the effect of the diarrhoea on the individual.
Dehydration:
- HR.
- PCV.
- TP.
Endotoxaemia:
- CE, HR, MMs.
Inflammation:
- fever.
Further testing to assess the effects of the diarrhoea on the horse.
Protein loss - TP and albumin (can have normal TP if high globulin and low albumin — e.g. some cyathostomiasis).
- ventral oedema (not all).
Electrolytes (Acute).
Acid-base (Acute, get acidaemic if severe - test once hydrated).
Test aimed at finding the cause of the diarrhoea.
Faecal sample - for bacteriology.
— serial samples for salmonella (3 x samples every 12-24 hrs).
— Clostridial toxins.
- egg count.
Maybe biopsy:
- IBD.
- neoplasia.
- culture (salmonella).
- encysted cyathostomes.
- rectal — easy, low risk and cheap.
— care when interpreting results .
- intestinal.
— laparoscopy vs laparotomy.
— standing vs GA.
— small vs large.
— can also inspect abdomen.
— generally consider if rectal biopsy was unrewarding.
Abdominoparacentesis:
- neoplasia.
— about 1/4 lymphoma cases and 3/4 SCC cases shed cells.
- inflammatory cells in IBD?
Abdo U/S:
- thickened intestinal wall.
— may see in some cases of:
—> IBD, right dorsal colitis (NSAIDs), neoplasia.
—> fairly poor specificity and sensitivity.
Treatment of chronic diarrhoea in the horse.
Horse usually relatively stable even if underlying cause serious.
Prioritise reaching diagnosis.
Then treat cause.
Treatment of acute diarrhoea in the horse.
Some treatment specific to the cause.
Treatment generally very similar.
Depends on severity.
If dehydration:
- make fluid plan — current dehydration, ongoing losses, maintenance.
- IV fluids usually best.
- monitor.
Feed, spike fluid bags as required and rehydrate to treat electrolyte imbalances.
Hydration to treat acid-base disturbances.
Hypoproteinaemia:
- plasma transfusion.
- may need to repeat.
- expensive.
Endotoxaemia:
- flunixin (NSAID) — judicious as can give colitis in itself.
- Polymyxin B - binds LPS.
- ice feet for laminitis.
Colic:
- Flunixin (with care).
- may need opioids.
- spasmolytics.
Bacteraemia/bacterial overgrowth.
- antibiotics - do you? Don’t you?
— if sick/toxic —> penicillin, gentamicin, metronidazole.
— if not, take faecal and blood culture first.
— watch for thrombophlebitis.
What is transfaunation?
Filter faeces from a healthy horse from the sick horse’s home environment.
NG tube.
After omeprazole to raise pH?
Several times.
Treatment - encouraging blood flow to the colon wall.
For healing of inflamed colon.
Including colonic ulceration.
Will also help gastric ulceration.
Oral sucralfate (currently made as a special).
Oral misoprostal (human drug).
- used to induce abortion in humans so be careful!
Both PG agonists.
Extras:
- Biosponge.
- Yeasacc.
- Probiotics? — no evidence for their efficacy at the moment.
4 clinical syndromes of salmonella enterica.
Inapparent infections with latent or active carrier states.
Depression, fever, anorexia, neutropenia, without diarrhoea or colic.
Acute enterocolitis with diarrhoea.
Septicaemia with or without diarrhoea.
- Route of salmonella infection?
- What if immunocompromised (e.g. stress or illness)?
- Risk of having carriers or infected horses?
- Faecal-oral route. Can persist in the environment.
- Carriers can get diseased.
Easier to get infected - Nosocomial infection.
Zoonosis.