Have you ever wondered why PAH recommends regular fecal testing? How is the test done and what exactly is tested for?
Simply put, a fecal exam is a check for intestinal parasites.
Here in the south, intestinal parasites are very prevalent for both dogs and cats. These parasites are transmitted to pets from everyday contact with the environment. We commonly encounter roundworms, hookworms, whipworms, tapeworms and coccidia. Companion animals with these pests may have diarrhea, anemia, and/or weight loss.
In addition to caring for animals, Veterinarians play an important role in public health. Fecal exams contribute to the health of humans and are especially important if your family includes very young children, senior citizens, or people who are immunocomprised (transplant patients or chemo recipients, for example).
According to the Companion Animal Parasite Council, 34% of dogs nationwide are infected with gastrointestinal parasites. In the southeastern U.S., up to 54% are infected. The Centers for Disease Control (CDC) has reported that 14% of people in the U.S. have been infected with roundworms. As a result of these infections, approximately 700 people lose their vision every year.
Okay, so it’s important to be sure that my pet does not have these parasites, but wasn’t last year’s test enough? I’ve been giving my pet monthly preventatives.
Unfortunately, even a parasite-infected animal may not come up positive on a fecal test. In fact, our staff does not refer to a test as “negative”, but rather as “no parasites seen”. There is always the possibility of human or equipment error, but often the parasite itself is just good at not making itself known. Worms are not always shedding eggs (which is what we are looking for in the stool sample).
Many of the monthly heartworm medications do prevent some intestinal parasite infections. Different drugs, however, are effective on different types of worms and may not be effective at all with other types of worms. There is also the possibility that a month could be missed or that your pet (unknown to you) spits out their medication.
For all these reasons, it is best to check for intestinal parasites as often as is reasonable. For adult animals showing no signs of gastrointestinal illness, once a year is great. For young animals, we’d like to check at least twice during their first few months of life. More frequent tests may be advisable, based on the pet’s health and lifestyle.
How is a fecal test done?
You may collect a fresh stool sample and bring it in the same day. A plastic zip-close bag works fine – you just want to be sure that the stool does not dry out. Fresher stool samples result in more accurate test results!
If you can’t bring a sample in, the hospital staff can collect a sample using a plastic tool called a “loop”. If we find that the pet’s gastrointestinal tract is “empty”, you can always bring in a sample at a later time. Although our staff is as gentle as possible, this procedure can still be scary and/or uncomfortable for some pets. These pets would probably prefer that you collect a sample at home.
Fecal tests involve looking for ova (eggs) in the stool sample. Each parasitic worm has slightly different looking eggs.
PAH uses the most accurate technique available for performing fecal tests. A small amount of fecal material is suspended in a solution that is supersaturated (heavy). The eggs are light and float to the top. The solution containing the fecal material is then spun in a centrifuge. The ova adhere to a cover slip, which is placed on a slide and is then viewed under the microscope using overlapping scans to be sure the entire slide is examined. Note that this entire procedure requires both time and expertise!
A fecal exam can detect roundworms, hookworms, whipworms, coccidia, and sometimes tapeworms. The exam does not always detect tapeworms, whipworms, and immature roundworms and hookworms. A fecal exam NEVER detects heartworms – a blood test is required!
Why not skip the test and just treat my pet with a broad-spectrum dewormer?
Your Veterinarian needs to know the relative numbers of each type of ova. Heavy infestations may be better treated with a different product. Some types of intestinal parasites (Coccidia and tapeworms, for example) require a completely different medication. It is important to target the treatment to the particular type and severity of parasitic infestation. By treatment with a broad-spectrum dewormer, the Veterinarian risks missing a type of parasite or not being able to gauge the seriousness of the situation.
And YES, we check our own animals yearly.