EQ diarrhoea Flashcards
(26 cards)
What areas of the GIT are affected in acute diarrhoea of the horse?
Colon/ caecum (colitis/ typhlocolitis)
What risk factors are associated with acute diarrhoea?
Antibiotics, transport, competition, hospitalisation, surgery - ie stress
What pathogens can cause acute diarrhoea in horses >9mo?
Salmonella, clostridium, cyathostomins, ehrlichia (also drug-related)
Describe the pathophysiology of SIRS.
Endotoxins and exotoxins produced by pathogens lead to an overwhelming release of inflammatory mediators (TNF, IL, complement) which damage endothelium
What clinical signs are associated with SIRS?
Haemodynamic alterations (shock, vasoconstriction/ dilation, oedema), coagulopathies, metabolic derangements (hypermetabolism, tissue hypoxia, acidosis), organ dysfunction (reduced GI motility, laminitis, renal dysdysfunction)
Which species of Salmonella is most associated with diarrhoea in the horse?
Typhimurium
What environmental factors can increase shedding?
High temperature, hospitalisation, transport, antibiotics, GI surgery, immunosuppression
What pathogenic characteristics are employed by Salmonella?
Gram -ve (endotoxins), mucosal damage (cytotoxins), osmotic diuresis (enterotoxins)
What results on a biochem may be associated with Salmonellosis?
Neutropenia (used in tackling Salmonella infection), hyponautraemia and dehydration (osmotic diuresis), septicaemia
Describe the sampling procedure used to ensure a horse is free of Salmonella.
5x negative faecal cultures taken 12 hours apart
What antibiotics are associated with antibiotic-induced diarrhoea?
Penicillin, ceftiofur, TMPS, oxytet, erythromycin
What bacteria is associated with antibiotic-induced diarrhoea (via overload)?
Clostridium deifficile
What antibiotic can cause fatal colitis as a side effect?
Oxytetracycline
What type of diarrhoea may be seen with antibiotic-induced diarrhoea?
+/- haemorrhagic
If a horse is >9% dehydrated how does this correlate with their fluid loss?
> 50L
If a horse is 7-9% dehydrated how does this correlate with their fluid loss?
40-50L
If a horse is 4-7% dehydrated, how does this correlate with fluid loss?
25-35L
What is the mechanism of action of polymixins?
They bind to LPS in the cell wall of gram-ves
What is the spectrum of activity of polymixins?
Enterobacteriaceae (salmonella), pseudomonas
What is the spectrum of metronidazole?
Anaerobes (gram-ve and +ve), protozoa (treponemes etc)
What oral protectants may be used in treatments of cases of diarrhoea?
Bismuth subsalicylate, activated charcoal, smectite (clay minerals)
What infectious causes are associated with infectious chronic diarrhoea?
Salmonella, listeria, parasitism, abscessation, rhodococcus equi
What non-infectious inflammatory causes are associated with chronic diarrhoea?
Sand ingestion, granulomatous enteritis, lymphosarcoma
What non-infectious, non-inflammatory causes are associated with chronic diarrhoea?
Abnormal fermentation or motility
