Why Does My Veterinarian Want a Poop Sample?

Posts by: 
Dr. Ruth MacPete, DVM
Dog Checkups & Preventive Care

Have you ever wondered why veterinarians recommend yearly fecal testing and what exactly is tested for? It’s not because we enjoy pet poop. We recommend “fecals” because they are an important part of your pet’s annual exam. Fecals allow veterinarians to check your pet for intestinal parasites. 

Intestinal parasites are a major cause of infection in pets and also a concern for people. According to Kansas State, 34% of dogs in the United States have some kind of intestinal parasite, and the Centers for Disease Control (CDC) says that 14% of people in the U.S. have been exposed to the roundworm. As a result of toxocara infections, approximately 700 people lose vision every year. Fecals are an important tool to ensure that your pet and your household are not infected and exposed to intestinal parasites, respectively.

What do fecals detect?
Fecals enable veterinarians to determine if your pet has intestinal parasites such as roundworms, hookworms, whipworms, coccidia and giardia. Since intestinal parasites live in your pet’s gastrointestinal tract, they are usually hidden from view. Unlike external parasites like fleas and ticks, most intestinal parasites are never seen. The only way to detect the presence of intestinal parasites and identify them is by doing a fecal.

How do you perform a fecal?
Since worm eggs, larvae and protozoan cysts are difficult or impossible to see with the naked eye, a fecal exam is done with a microscope. There are three different ways to prepare a stool sample for examination:

• Smear— A smear is the easiest to do and involves smearing a small sample of stool across a microscope glass slide and examining it under the microscope.
• Flotation— A flotation (also known as a float) is the most common method used in veterinary hospitals and involves mixing the stool sample in a special solution that allows the eggs and protozoan cysts to float to the surface. While this option is common, it is not recommended.
• Centrifugation— Centrifugation is another form of flotation, and if fecal is done in clinic, this is the recommended method. It involves using a centrifuge to spin down a stool sample suspended in a special solution prior to performing the floatation. The parasites are then identified microscopically based on the size, shape and characteristics of their eggs, larvae or cysts (found in the stool specimen). 
• Antigen testing - Done at the reference lab, fecal antigen testing detects more hookworm, roundworm, and whipworm infections even when eggs aren't present.

​How to provide a proper fecal sample?
When it comes to food, we all know that fresh is best. Not surprisingly, the same is true for stool samples. The fact is that fresher stool samples give you more accurate and sensitive results. Eggs and larvae from some types of parasites, as well as protozoa and protozoan cysts, can become altered and unrecognizable the longer they sit out. For the best results, collect the freshest stool sample and bring it to your veterinarian the same day. If this is not possible, you can seal the fecal sample in a ziploc® bag and refrigerate it until you can bring it to your veterinarian. If you’re putting it in your refrigerator, I recommend being extra careful to not dirty the outside of the ziploc® bag and double bagging it to insure you do not contaminate your fridge and food. But remember, fresher is better!

How often does your pet need a fecal?
According to the Companion Animal Parasite Council (CAPC), adult pets should be tested twice annually, and puppies and kittens 4 times in the first year of life. Speak with your veterinarian to find out how frequently you should bring in your pet’s stool sample. Ultimately, the goal is to identify and treat parasitic infections that may be compromising your pet’s health and even putting your family at risk. Along with monthly, year-round parasite preventatives; routine fecal exams are the best way to ensure that your pet and your household are safe from intestinal parasites.

If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.

See more about intestinal parasites
Parasites in New Pups
Parasites Leading to Surgery
What is Whipworm and Why Should I Care?
What are Hookworms and Why Should I Care?
What are Roundworms and Why Should I Care?
Intestinal Parasites in Dogs 101 
​Or learn more about dogs and parasites >

Reviewed by: 
Sarah Sweet, DVM