Maldigestion in Cats (Felis) | Vetlexicon
felis - Articles


ISSN 2398-2950


  • Cause: lack of digestive enzymes or bile acids, eg exocrine pancreatic insufficiency, intestinal disease.
  • Signs: small intestinal diarrhea, sometimes colitis Diarrhea: dietary.
  • Diagnosis: signs, laboratory tests.
  • Treatment: supplementation of deficient enzymes if possible, dietary manipulation.
  • Prognosis: can be good - depends on etiology.

Presenting signs

  • Weight loss.
  • Polyphagia.

Age predisposition

  • Young animals with congenital conditions.




  • Exocrine pancreatic insufficiency   →   reduction in digestive enzymes in duodenum   →   impaired digestion of carbohydrate, fat and protein   →   osmotic diarrhea   →   bacterial metabolism of undigested fat and protein   →   hydroxylated fatty acids   →   act as secretagogues and also may cause inflammation of colon.
  • Brush border disease   →   reduced activity of lactase and dipeptidases   →   impaired digestion of carbohydrate and protein. Usually secondary to intestinal disease and causes malabsorption.
  • Bile acid deficiency   →   reduced emulsification of fats   →   impaired fat digestion.


Presenting problems

  • Chronic diarrhea.
  • Weight loss.
  • Polyphagia.

Client history

  • Weight loss.
  • Polyphagia.

Clinical signs

  • Poor body/coat condition.
  • Hepatic enlargement/jaundice.

Diagnostic investigation

  • See chronic diarrhea.



  • Intestinal biopsy may be normal.

Fecal analysis

  • Examination for fat or starch in feces.


  • Absorption tests:
    • Fat absorption.
    • Xylose absorption.

Confirmation of diagnosis

Discriminatory diagnostic features

  • Signs.

Definitive diagnostic features

  • Detect (EPI) pancreatic disease - TLI, pancreas biopsy.
  • Specific laboratory tests for brush border enzymes deficiency.

Gross autopsy findings

  • Intestinal autolysis is rapid, so examine and prepare samples promptly.
  • Systematic examination to rule out other causes of weight loss. Check bile duct patency by manual expression into duodenum.
  • Save feces for examination.

Histopathology findings

  • Fix multiple regions of gastrointestinal tract, (handle carefully, place serosal surface on card to prevent curling), plus liver, kidney, pancreas.
  • Consider fixing intestine for electronmicroscopy and fresh unfixed tissues for laboratory tests of brush border enzymes. Consult lab.

Differential diagnosis

  • Diarrhea - intestinal causes - malabsorption.
  • Hyperthyroidism Hyperthyroidism.


Initial symptomatic treatment

  • Modify diet.
  • Low-fat, highly digestible diet .

Standard treatment




  • Depends on cause but can be favorable.

Expected response to treatment

  • Weight gain.

Reasons for treatment failure

  • Incorrect diagnosis.
  • Concurrent disease, eg giardia, cryptosporidia, campylobacteriosis Campylobacter jejuni not treated.

Further Reading


Refereed papers