Diarrhoea in the cat and dog

Question 1

Define haematoxhezia

Answer 1

Fresh blood in stool

Question 2

Define diarrhoea

Answer 2

Increased frequency, volume or fluidity

Question 3

Differentiate acute and chronic diarrhoea

Answer 3

ACUTE 3 weeks, could be intermittent signs, investigate

Question 4

How do you distinguish SI/LI/mixed?

Answer 4

HISTORY!
SI - primary or secondary GI disease
LI - confined to colon

SI PROBLEMS: volume, weight loss, V (both), general condition
LI PROBLEMS: mucus, frequency, tenesmus, dyschezia

Question 5

Define dyschezia

Answer 5

Difficult or painful defecation

Question 6

Differential diagnoses - acute SI diarrhoea, NO systemic signs - 4

Answer 6

• Diet (fast animals to determine if this is cause but be careful with cats as they don’t tolerate this well!)
• Helminths
• Protozoa - giardia
• Iatrogenic - drugs

Question 7

Differential diagnoses - acute SI diarrhoea, WITH systemic signs - 5

Answer 7

-BACTERIA- salmonella or campylobacter (FAECAL CULTURE)
- VIRAL - distemper and parvo (dogs), panleukopaenia (cats) (do a faecal antigen test)
TOXINS
-HAEMORRHAGIC GASTROENTERITIS (dogs; high PCV, dehydrated)
-ACUTE PANCREATITIS (test - ultrasound and pancreatic lipase)

Question 8

Differential diagnoses - acute LI diarrhoea, NO systemic signs - 4

Answer 8

-Whipworms
-Clostridia
-Giardia
-Campylobacter
RUN FAECAL EXAM AND CULTURE

Question 9

DDx - chronic SI diarrhoea, EXTRA-GIT - 2 (with examples of each) and GIT - 8

Answer 9

EXTRA-GIT:

• METABOLIC: hepatic disease (PSS), hyperthyroidism (cats), addison’s disease (dogs), renal insufficiency
• PANCREATIC: EPI or chronic pancreatitis

GIT:

• Giardia
• chronic partial obstruction
• lymphagiectasia
• neoplasia - lymphosarcoma
• food-responsive disease
• IBD (lympho-plasmacellular)

Question 10

DDx - chronic LI diarrhoea, GIT signs

Answer 10

GIT:

• IBD (lympho-plasmacellular, ulcerative colitis in boxers)
• polyps
• food-responsive disease
• neoplasia - usually adenocarcinomas
• chronic partial obstruction
• Cats: Tritrichomonas foetus

Question 11

6 investigations for CHRONIC diarrhoea (order important)

Answer 11

• Faecal exam (flotation, culture) - excludes parasites/bacteria
• Heamatology, biochemistry and urinalysis (UA) - excludes systemic disease
• if SI diarrhoea: TLI (for EPI), pancreatic lipase/PLI (for pancreatitis), cobalamin (low levels indicate disease of ileum)
• Abdominal ultrasound - where is lesion? obstruction?
• Empiric treatment with elimination diet - food responsive disease
• if no response, biopsy/endoscopy

Question 12

Advantages - endoscopy

Answer 12

• multiple biopsies from stomach, prox SI, ileum and colon possible
• non-invasive (except GA)
• direct visualisation of mucosa
• gives diagnosis (majority of cases)
• Difficult to diagnose intestinal lymphoma or lymphagiectasia as you only take a partial thickness biopsy

Question 13

Disadvantages of biopsies via exp. lap. 4

Answer 13

• Invasive - caution in sick animals/cats/animals with decreased albumin levels
• only 2-3 biopsies from stomach and SI, not for colonic biopsies!
• more expensive and painful
• 20% mortality vs 2% mortality with endoscopy

Question 14

Main causes for CHRONIC SI Diarrhoea in dogs - 4

Answer 14

• Food-responsive disease
• AB-responsive diarrhoea
• IBD (lympho-plasmacellular enteritis/colitis)
• Neoplasia

Question 15

Define food-responsive disease

Answer 15

Diarrhoea gets better when given elimination diet (protien that animal has never eaten before, in reality this is pretty difficult so in fact a hydrolysed diet is given when the proteins are already broken down into oligopeptides). Usually better within first 2 weeks. Keep on this for at least 6-8 weeks. Then the animal can often be switched back on to original diet without clinical signs.

Question 16

Define ARD

Answer 16

Antibiotic Responsive Diarrhoea (formerly SIBO).
Most commonly seen in young GSDs
Chronic SI or mixed diarrhoea
Give metronidazole for 4 weeks. Usually relapse though despite an initial quick recovery.

Question 17

How do you diagnose IBD? Frequency? What do you seen on histopathology? What is the mechanism of IBD?

Answer 17

• By clinical exclusion! Most common enteropathy in dogs.
• Histopathology –> lymphoplasmacellular (most common), eosinophilic (rare), ulcerative colitis (only LI, rare, Boxers)/

-MECHANISM: IBD involves a mutated PRR (enterocytes and/or DCs in GIT) that wrongly identify commensal bacteria as pathogenic bacteria. The immune response to the ‘pathogenic bacteria’ is augmented meaning there is a massive increase in Th17 cells leading to massive mucosal inflammation. The anti-inflammatory cytokines produced by Tregs are insufficient to counter/balance this.

Question 18

List the therapies for chronic enteropathies/IBD in DOGS (in a sequential treatment protocol) - 3

Answer 18

1. ) Elimination diet
2. ) METRONIDAZOLE for 3-4 weeks
3. ) If inadequate response: PREDNISOLONE for at least 10 days then taper dose (i.e. an immuno-suppressive drug). If this steroid doesn’t work or is poorly tolerated, then use AZATHIOPRINE or CYCLOSPORINE.

Question 19

List the therapies for chronic enteropathies/IBD in CATS (in a sequential treatment protocol) - 4

Answer 19

1. ) Elimination diet
2. ) PREDNISOLONE (10-14d then slow taper)
3. ) If no response - CHLORAMBUCIL
4. ) COBALAMIN supplementation: most cats with SI diarrhoea have low cobalamin levels.Studies show if you don’t give this PN, other treatments won’t work.

Question 20

Define protein losing enteropathy

Answer 20

Syndrome of intestinal diseases. Non-selective protein loss - albumin low, +/- globulins low (both indicative of loss through GIT).

Question 21

Causes - protein losing enteropathy - 3

Answer 21

• IBD
• Lymphagiectasia
• Neoplasia (lymphoma)

Question 22

Clinical signs - protein losing enteropathy - 5 What must you do quickly?

Answer 22

• Diarrhoea
• Vomiting, anorexia
• Weight loss
• Ascites, pleural effusion (due to low albumin/globulin –> oedema), peripheral oedema
• Usually albumin and globulin serum concentrations low

-Take biopsy early!