How to Collect a Stool Sample

Laurie Anne Walden, DVM

Photo by Lucas Ludwig

Pets need stool tests to screen for parasites or help find the cause of diarrhea and other digestive system problems. Collecting a stool sample at home is the least stressful option for the pet. The alternative is for someone at the veterinary clinic to use a loop to remove a little bit of stool from the rectum. This option yields a much smaller sample and can be unpleasant for the animal.
 
A fecal test for parasites involves mixing the stool sample in a flotation solution and either spinning it in a centrifuge or leaving it to sit in a vial for a certain amount of time. The material at the top of the solution is then removed to a microscope slide to look for parasite eggs that have floated to the surface. Sometimes a tiny bit of stool is smeared directly onto a microscope slide for examination. Fecal analysis can also include chemical tests. For all of these tests, the stool needs to be fresh and squishy enough to mix or smear.
 
The age and condition of a stool sample affect the results. Parasite eggs can dry out or hatch in old stool. Hard, dry feces is very difficult or impossible to prepare for testing. Stool that has been sitting outdoors for a while can contain fly eggs or larvae (maggots). Liquid diarrhea that’s soaked into paper or cloth can’t be mixed in solution to test for parasites.
 
Here’s how to collect a stool sample to get the most accurate results:

• Collect a fresh sample that’s less than 24 hours old.
• Collect at least a 1-inch chunk if possible.
• Wear disposable gloves or put a plastic bag over your hand to collect feces. Wash your hands afterward.
• Bring the sample to the clinic in a plastic bag or sealed container (your veterinary clinic can give you a container if you need one).
• It’s fine if some grass, leaves, mulch, or cat litter is stuck to the feces.
• If the stool is runny, don’t soak it up with a paper towel; scoop the runny stool as best you can into a plastic bag or container.
• For dogs, collect the sample right after the dog defecates.
• For cats, collect a fresh sample from the litter box. If your cat usually goes outdoors to defecate, keep him indoors until you can get a sample.
• Bring the sample to the veterinary clinic within 24 hours of collection.
• Fecal samples can be kept at room temperature or refrigerator temperature but not frozen.

 
Photo by Lucas Ludwig on Unsplash

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