Parasites are organisms that live on (external) or within (internal) an animal, deriving their nutrition and protection at the expense of the animal. The infected animal is called the host. Some common internal parasites of dogs include: Roundworms, Hookworms, Tapeworms, Whipworms, Giardia, and Coccidia.
Microscopic exam of your pet’s fresh stool sample is necessary to determine the presence and type of intestinal parasites. We recommend testing your dog every 6-12 months for internal parasites.

Roundworms (Ascarids) are the most common intestinal parasite of dogs and cats. Pets become infected by swallowing roundworm eggs found in contaminated soil or feces, or by eating infected rodents, birds and certain insects. Puppies and kittens are commonly infected by the mother while she is pregnant.

Hookworms live in the small intestine. They feed on the blood of their host and can cause severe anemia. In young, weak, or malnourished animals, hookworms can cause sudden collapse and death. Weight loss, diarrhea and tarry or bloody stools can occur in animals with hookworms.

Tapeworms are worms which live in the intestines of dogs and cats. Tapeworms are not passed directly from pet to pet, but require an intermediate host in which to develop. Common intermediate hosts are fleas and small animals, such as mice, rats, squirrels and rabbits. Segments that are passed in the stool are yellowish to white, about ¼ inch long and can resemble cucumber seeds or grains of rice. Segments may be found in your pet’s bedding, or clinging to the hair around the anus.

Whipworms are small, thin worms that live in the cecum and large intestine. Eggs are passed in the stool Whipworms can cause diarrhea, bloody feces, and poor general health. Massive rectal bleeding can occasionally occur.

Giardia is an intestinal parasite of people, dogs, cats and other animals. It is caused by ingesting the Giardia organism from contaminated stool, food, or water. The most common sign of infection is persistent diarrhea, with pale, greasy and occasionally blood-tinged stool. Giardia prevents proper absorption of nutrients, damages the delicate intestinal lining, and interferes with digestion. Giardia can be difficult to identify microscopically and may require multiple stool samples or special staining techniques to diagnose.

Coccidiosis is a parasitic disease of the small and large intestine caused by a microscopic organism called coccidia. Coccidia causes damage by rupturing cells of the small intestine, which often leads to bleeding. This disease spreads from one animal to another by contact with infected feces. It is most severe in young or weak animals and often causes bloody diarrhea.

The most important step in parasite prevention is the routine examination of stool samples and maintaining a clean environment for your pet. Since most parasites are passed in the stool, it is important to clean up stools daily, so your dog does not re-infect itself from the stool in the yard. We recommend checking stool samples 1-2 times per year.

Humans can be infected by many types of parasites common to our animal companions, however, these types of infections are not common. Transmission is through ingestion of eggs which are passed in you pet’s stool. Therefore, it is important to keep stools picked up and to practice good hygiene after playing with your puppy. This is especially important with children, as they are more likely putting their fingers in their mouths or eating without washing their hands. Remember, the best way to prevent infection in your pets or your family members is by routine screening of your pet’s stool and prompt treatment when an infection is found.