Contributors: Helen Milner, James Simpson
Species: Canine | Classification: Lab Tests
- 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.
- Simplicity of method to assess maldigestion Maldigestion , eg the results may support a putative diagnosis of Exocrine Pancreatic Insufficiency (EPI) Exocrine pancreatic insufficiency.
- 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.
- 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.
- Staining rack.
- Microscope slides.
- Sudan3 stain.
- Lugols iodine stain.
- Fecal containers.
- 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.
Errors and Artifacts
- Poor staining technique.
- No starch, fat or muscle fiber in the diet.
- Fecal smear too thick.
- Recent references from VetMedResource and PubMed.
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.