Small Intestinal Disease (TV4102, Lecture 21 Notes)

List clinical signs of intestinal disease

- Diarrhoea (increased frequency/volume of faeces), include osmotic, secretory, malabsorptive, motility or mixed types

- Vomiting

- Weight loss

- Melaena/haematochezia

- Ill thrift

- Ascites or abdominal distension

- Thromboembolism

- Anorexia/hyporexia

- Retching/gagging

Compare and contrast small and large bowel diarrhoea

Compare and contrast extra- and intra-GI diarrhoea

Extra-GI - disease process arises outside the GI tract and manifests as diarrhoea.

e.g. hepatic, renal or endocrine

Intra-GI - disease process directly affects GI tract.

e.g. infection, immune mediated or neoplasia

Discuss clinical approach to small intestinal disease

- History and physical exam

- CBC and biochemistry

- Consider serum bile acids and resting cortisol

- Diet trial for 4-6weeks with hydrolysed or novel protein (including venison, tofu, ostrich or kangaroo) diets, reintroduce new foods every 2-4weeks

Discuss hydrolysed diets

- Enzymatic reduction of protein to peptides

- Lose tertiary structure and immune "fingerprint"

- Less visible to immune system

Discuss antibiotic responsive diarrhoea

- Considered idiopathic condition

- Respond to long-term antibiotics, including metronidazole or tylosin

- Diarrhoea stops with ABs and starts again when discontinued

Discuss eosinophilic enteropathy

- Parasites/infection or immune mediated

- Diagnosed on biopsies

- Treat underlying cause, prednisolone with no resolution

- Good prognosis

Discuss feline gastrointestinal eosinophilic sclerosing fibroplasia

- Common in Ragdoll cats

- Causes focal mass-like lesion and obstruction

- Biopsy for definitive diagnosis

- Surgical resection or corticosteroids

- High survival rate, may recur

Discuss protein losing enteropathy

- Syndrome with loss of protein in intestine and low cholesterol

- Due to IBD, familial, lymphangiectasia or breed-specifics

- Requires endoscopic biopsy

- Present with panhypoproteinaemia, hypocholesterolaemia, ascites and thromboembolism

Discuss intestinal lymphangiectasia

- Dilation of lacteals in intestine, causing the leakage of protein

- Due to congenital, back pressure, inflammation or obstruction

- Diagnose with endoscopy or biopsy

Discuss treatment of protein-losing enteropathy (and intestinal lymphangiectasia)

- Drain ascites if they are uncomfortable

- ACE inhibitors

- Anti-thrombotic drugs, including Clopidogrel or Rivaroxaban

- Diuretics, including Spironolactone or Frusemide

- Underlying cause (if present)

- Glucocorticoids

Discuss congenital hypocobalaminaemia

- Assess cobalamin, methyl malonate or homocysteine levels

- Administer B12

Discuss inflammatory bowel disease/chronic enteropathy (IBD)

- Chronic antigenic stimulation with loss of tolerance

- Causes loss of protein, malabsorption, weight loss and protein-losing enteropathy

- Rule out extra-GI disease and infection

- Perform abdominal ultrasound (low sensitivity, must differentiate from alimentary lymphoma), endoscopy/exploratory laparotomy or histology

Compare and contrast alimentary lymphoma and IBD

- Large Cell High Grade, guarded prognosis with CHOP chemotherapy

- Small Cell Low Grade, good prognosis with Chlorambucil

- Differentiate with immunohistochemistry or clonality

Compare and contrast endoscopy and laparotomy

Discuss treatment of IBD

- Prednisolone 1-2mg/kg/D

- Monitor response and taper to lowest effect

- Try control long term with diet (hydrolysed/novel)