GI - equine diarrhoea Flashcards
Where does diarrhoea always originate from in horses?
Large intestine
How much fluid enters the GI tract and is absorbed in the LI in 24 hours in a horse?
100L / 24 hours
What is the term for bowel inflammation?
Colitis
What are the 3 main mechanisms of diarrhoea from inflammation in horses?
Malabsorption
Increased secretion
Decreased transit time
What does GIINANDDTONIICC stand for?
Genetic
Infection
Inflammation
Neurologic
Autoimmune
Nutritional
Developmental
Degenerative
Trauma
Ormonal (hormonal)
Neoplastic
Iatrogenic
Idiopathic
Cardiovascular
Chemical and toxic
What are the main differentials of chronic colitis?
Chronic salmonellosis
Parasites - strongyles, cyathostomes
Sand eating
Inflammatory bowel disease
Neoplasia - lymphoma
NSAIDs
What are the main differentials for acute colitis?
Salmonella, clostridia
Cyathostomes
Rotavirus - foals
Nutritional - diet change
Idiopathic
NSAIDs
What is the most common cause of acute diarrhoea?
Idiopathic - most acute colitis
What tests should you do in diarrhoea cases to assess dehydration?
Heart rate - skin tent doesnt work
Can do PCV/TP in lab
What test can you do for protein lost?
Total proteins and albumin
What tests should you do to find the cause of the diarrhoea?
Faecal sample - for bacteriology and egg count (for strongyles)
Biopsy - rectal or intestinal
Abdominoparacentesis
Abdominal ultrasound
What can you evaluate for on a GI biopsy?
IBD
Neoplasia
Culture - salmonella
Encysted cyathostomes
When should you do an intestinal biopsy? How do you do it?
In chronic cases if rectal biopsy was unrewarding - not common
Standing or GA - laparoscopy or laparotomy
What is an abdominoparacentesis?
Belly tap
What can you evaluate for on abdominoparacentesis?
Neoplasia - lymphoma, SCC
Inflammatory cells - IBD
How do you treat chronic diarrhoea?
Horse usually stable so reach diagnosis then treat the cause
How do you treat dehydration due to acute diarrhoea?
Make a fluid plan
IV fluids
Monitor
How do you treat electrolyte and acid base imbalance in horses with acute diarrhoea?
Feed
Hydrate
Then spike fluid bags
How do you treat hypoproteinaemia in horses with acute diarrhoea?
Plasma transfusion
(expensive)
How do you treat endotoxaemia in horses with acute diarrhoea? What are the risks?
Flunixin - anti-endotoxic drug
Can cause colitis itself - balance risk of laminitis with risk of increasing colitis
Polymyxin B - binds LPS
How do you treat bacteraemia/bacterial overgrowth in horses with acute diarrhoea?
If sick/toxic give penicillin, gentamycin, metronidazole
Take faecal and blood culture
What is transfaunation?
Filter faeces from a healthy horse from the sick horses hone environment
Then nasogastric tube it several times
What drugs can you give to encourage blood flow to the colon wall in horses with acute diarrhoea?
Prostaglandin agonists:
Oral sucralfate
Oral misoprostal
What parasite causes massive inflammatory reaction, severe diarrhoea and often death in horses when they all emerge at once?
Cyathostomes
What do cyathostomes look like?
Small redworm
Where do the cyathostomes encyst? For how long?
Encyst in the large intestinal mucosa for 2-3 years
How do you treat cyathostomiasis?
Moxidectin - be careful of inflammation from dead worms causing colitis
Concurrent corticosteroids to reduce inflammation
What worm parasite affects foals through dams milk causing diarrhoea 6 months later?
Strongyloides westeri
What are the 4 clinical syndromes for salmonella in horses?
Latent/active carrier
Depression, fever, anorexia, neutropenia but no diarrhoea or colic
Acute enterocolitis with diarrhoea
Septicaemia with/without diarrhoea
How is salmonella spread?
Faeco-oral transmission
Persists in environment
What are the signs of acute enterocolitis due to salmonella in horses?
Fever, anorexia
Endotoxaemia - shock, laminitis, thrombophlebitis
Pink gums
Diarrhoea - 24-48 hours after pyrexia
Dehydration
Colic
When should you isolate a horse under suspicion of salmonella?
If it has any two of
Pyrexia
Depression
Diarrhoea
Leukopenia
What is the prognosis of salmonella?
Need aggressive treatment - can be complications, become carriers, develop chronic salmonellosis
Poor if persists more than 4-5 weeks
What can trigger clostridia infection in horse GI tract?
Antibiotic administration
Are clostridia normally found in the gut?
Yes, but not those producing enterotoxin
What does lawsonia intracellularis cause in horses? When?
Proliferative protein-losing enteropathy in small intestine, diarrhoea
How does lawsonia intracellularis cause diarrhoea in horses?
Alters nutrient absorption and fluid secretion by disrupting villi and stopping epithelial cells maturing into absorptive cells
At what age does lawsonia intracellularis affect horses?
At weaning - 4-6 months old foals
What is seen on ultrasound in lawsonia intracellularis infection?
Marked thickening and oedema of intestinal wall
How do you treat lawsonia intracellularis?
Supportive treatment and plasma infusion
Doxycycline - orally
Where does NSAID induced colitis occur in the horses body?
Right dorsal colitis
What are the clinical signs of NSAID induced colitis?
Anorexia, lethargy
Colic
Diarrhoea
Protein losing enteropathy - ventral oedema
How do you treat NSAID induced colitis?
Stop NSAIDs
Analgese with opioids and buscopan, paracetamol maybe
Treat colitis
What can cause antibiotic induced colitis in horses that havent been given antibiotics themselves?
Dams ingesting foals erythromycin when they clean their face/butt
What bacteria tends to overgrow in antibiotic induced colitis?
Clostridia
What are some causes of IBD in horses?
When get excited
When on haylage
Spectrum of conditions
How do you diagnose IDB in horses?
Ultrasound
Peritoneal fluid sample - inflammatory cells
Biospy if these fail
How do you treat IBD?
Corticosteroids - pred
? Resection
? Short fibre diet
? Yeasacc
What causes ‘foal heat’ diarrhoea in foals?
Change in GI function
What is a common virus which causes diarrhoea in foals?
Rotavirus
What is the most common bacterial cause of diarrhoea in foals up to 2 weeks old?
Gastroenteritis - failure of passive transfer
What is the most common bacterial cause of diarrhoea 3 months old plus in foals?
Rhodococcus
How can you correct hypoalbuninaemia in horses?
Blood plasma
What does a high heart rate indicate in a horse?
Pain
Dehydration
Endotoxaemia
What is the treatment for a horse with mild diarrhoea who doesnt seem systemically ill?
Transfaunation
Maybe biosponge
