Intestinal Parasites in Dogs and Cats

Intestinal parasites are very common in both dogs and cats. Some pets can have intestinal parasites without showing any signs of illness, while other pets may show mild, moderate, or severe clinical signs of illness. In some cases, parasites may migrate outside of the GI tract to other parts of the body, including the lungs, liver, and other organs. In those cases, pets may show signs related to the specific organs affected; for example, pets with lungworm may cough or have signs of respiratory distress. Importantly, some dog and cat parasites are capable of infecting people and may cause significant illness if they migrate to other organs or body systems.

The most common intestinal parasites in dogs and cats are roundworms, tapeworms, hookworms, whipworms, coccidia and giardia. Some parasites can be seen by pet families in their pet’s stool; they may appear like grains of rice or spaghetti. Importantly, the absence of “worms” in the stool does not rule-out infection, as some parasites are only intermittently shed in the stool and others are too small to be seen at all. A fecal exam is often performed to evaluate for parasite eggs in the stool. In cases where this initial test is not definitive or a more complicated GI infection with other types of parasites is suspected, the feces may be submitted for additional testing.

Treatment for intestinal parasites typically involves an anti-parasitic medication. Depending on the type of medication, the type of parasites diagnosed, and the parasite burden, anti-parasitic medications may be given once or as a several-day course. The life cycle of the parasite and the age of the pet may necessitate that the treatment regimen be repeated. Less commonly, certain parasitic infections may also require an antibiotic and/or additional supportive care. A monthly preventative medication (such as heartworm preventative) is recommended in all patients to prevent new or recurrent parasite infection.