I saw a worm in my pet’s stool. Now what do I do?
First and foremost, carefully collect the specimen. Your pet’s doctor may need to see the worm to make an accurate diagnosis. Use disposable gloves, wrap the worm in a moistened paper towel and put it in a plastic bag. Keep it cool until you can deliver it to your veterinarian.
Most commonly we determine the presence or absence of intestinal parasites in our patients by a test called Fecal Flotation (FF). The test is performed by mixing a portion of stool with a special laboratory liquid called Fecal Flotation Solution. There are a number of formulas for the solution and each one has its advantages: some parasites and their eggs float better in a sucrose solution, some are easier to find in a Zinc Sulfate or Sodium Nitrate solution. Fecal flotation solutions are formulated to have a very high specific gravity, causing parasite eggs to float to the top of the mixture.
After thorough mixing the solution is poured into a test tube and a thin cover glass is place on top. Parasite eggs that float to the top of the mixture stick to the cover glass.
The next step is the passage of time. A good FF needs at least ten, but preferably fifteen or even twenty minutes to process before being read on a microscope.
The fecal flotation test looks for the eggs of worm parasites, which give away the presence of the adult parasites in the intestine, still attached to the wall of the GI tract. This, though, is where the importance of bringing in the actual worm comes in. Several scenarios are possible:
- If eggs are seen by the test reader they are identified by size, shape and color as belonging to the parasite that produced them.
- Just as some people don’t have children, some worms don’t produce eggs, or they generate eggs in small numbers or intermittently. Whipworms, for example, might produce eggs once every few days. Therefore, what we read as a “negative” test result because no eggs were seen might actually miss the presence of intestinal parasites that simply didn’t have eggs in the sample tested. In the case of a worm that was found, but no eggs are found on the fecal flotation, identifying the adult worm is our best chance of knowing exactly what parasite has infected your pet. This very scenario happened today with our patient, Dakota, a young and lively Spitz.
- Sometimes there are worms on our pets or in their stools that are not parasitic. These are worms that didn’t even come from your pet, rather they got stuck to his hair while he was lying in the sun outdoors, or climbed into the pile of stool to feed on its nutrients. Just this month Pooky’s mom brought me an ugly, black, tapered worm that she found in his stool. Ugly as it is, it isn’t dangerous, just a creature from the ground that happened to see a free meal Pooky provided.
By the way, when time comes for your pet’s routine visit and a stool test is called for, take along a sample of his stool, about a tablespoon. Doing so will prevent your pet’s doctor from having to use a probe to enter his colon to obtain a stool sample, making your cat or dog’s doctor visit much more pleasant.
See you tomorrow, Dr. Randolph.
