Contributors: Helen Milner, James Simpson

 Species: Canine   |   Classification: Lab Tests

Overview Sampling Tests Result Data Further Reading


  • Examination of fresh fecal samples for the presence of undigested starch, fat or muscle fiber Fecal analysis: overview.
  • No such material should be present in health.




  • Presence of food components (starch, fat or protein) is not specific for any disease.
  • Putative diagnoses likely to need further diagnostic tests, eg EPI should be confirmed with Trypsin Like Immunoassay (TLI) testing Blood biochemistry: trypsin-like immunoreactivity.


  • Carry out a serum TLI test, which is definitive for EPI.

Risk assessment

  • Observe Health and Safety regulations when handling feces, stains and other in-contact consumables.


Sample Collection Technique

  • Ensure starch, fat and muscle is present in the diet before collection of feces.
  • Collect fresh fecal samples for examination.


  • Microscope.
  • Staining rack.
  • Microscope slides.
  • Sudan3 stain.
  • Lugols iodine stain.
  • Spatulas.
  • Fecal containers.
  • Pipettes.



  • Collect fresh feces in a suitable container.
  • Using a spatula apply a thin film of feces to 2 microscope slides.
  • Place slides on staining rack.
  • Flood 1 slide with Lugol's iodine Fecal analysis: Lugol's iodine and the other with Sudan 3 stain Fecal analysis: Sudan 3.
  • Leave for 5 minutes.
  • Decant excess stain.
  • Dry underside of slide.
  • View under low power (eg x4) microscopy for black starch granules (Lugols stain) and for red fat granules (Sudan 3 stain).


  • Dispose of consumables and fecal material following Health and Safety regulations.

Technician (Extrinsic) Limitations

  • Test procedures easily carried out in practice laboratory with little additional technical skill required.

Result Data

Errors and Artifacts

  • Poor staining technique.
  • No starch, fat or muscle fiber in the diet.
  • Fecal smear too thick.

Further Reading


Refereed papers

Other sources of information

  • Manual of Small Animal Clinical Pathology (1998) Eds: Davidson M, Else R & Lumsden L. BSAVA, UK.
  • Clinical Textbook for Veterinary Technicians (1998) 4th edn. Ed: McCurnin. W B Saunders.
  • Laboratory Procedures for Veterinary Technicians (1997) 3rd edn. Ed: Pratt. Mosby.