Diseases Vets Test for in Fecal Samples for Dogs

by Victoria Lee Blackstone
    Raw salmon can cause salmon poisoning disease, a condition diagnosed through fecal tests.

    Raw salmon can cause salmon poisoning disease, a condition diagnosed through fecal tests.

    Creatas/Creatas/Getty Images

    While the mere mention of collecting a sample for a fecal test is enough to make many dog owners cringe, this test is a powerful diagnostic tool for your veterinarian. Whether a regular checkup finds a parasitic infection or your dog is experiencing gastrointestinal symptoms, a fecal test allows your veterinarian to look for a variety of parasites and worms.


    Intestinal worms, such as roundworms, hookworms, whipworms and tapeworms, are common in puppies and dogs. These worms can cause symptoms such as diarrhea, blood loss, weight loss, vomiting and lethargy. Only roundworms and tapeworms are large enough to see with the naked eye, and you can find them in infected stool. Other worms, and worm eggs, are found when the veterinarian performs a fecal test and places the stool under a microscope. Positive ID allows the vet to choose the appropriate worming treatment.


    The protozoan parasite Giardia intestinalis causes giardia infection in dogs, causing a foul-smelling diarrhea, often with mucus or blood. This is a zoonotic condition that can spread to human companions. Diagnosis of giardia occurs through fecal testing. The cysts stage of the parasite passes into the dog’s feces and can be detected through a fecal float test and microscopic examination. In a fecal float test, a suspension medium separates fecal debris from possible parasites, making a cleaner sample for the microscope.


    Another intestinal parasite, Cryptosporidium, causes cryptosporidiosis in dogs. Your dog picks up this parasite through ingestion of contaminated water, food or feces. Symptoms include fever, diarrhea, lethargy, muscle weakness and lack of appetite. Cryptosporidium is a zoonotic parasite and your dog can spread the infection to you. Diagnosing cryptosporidiosis occurs through fecal flotation and fecal spears under the microscope.

    Salmon Poisoning

    Salmon poisoning is a condition found in dogs in the Pacific Northwest. The condition occurs when dogs eat raw fish from San Francisco to Alaska. Possible fish include salmon, trout, lamprey, sculpin, sturgeon and candlefish. The organism responsible for infection is Neorickettsia helmonthoeca. Symptoms include fever, anorexia, vomiting, diarrhea, nasal discharge and weight loss. A fecal test reveals the parasite’s eggs.

    Photo Credits

    • Creatas/Creatas/Getty Images

    About the Author

    Victoria Lee Blackstone is a horticulturist who propagates heirloom and native plants for her nursery. She has authored research-based scientific/technical papers, plant care sheets and magazine and newspaper articles. Blackstone studied botany and microbiology at Clemson University and is a former University of Georgia Extension Master Gardener Coordinator.

    Trending Dog Behavior Articles

    Have a question? Get an answer from a Vet now!