Intestinal parasites are small or microscopic organisms that live in the intestinal tract (digestive system) of dogs and cats. There are many different intestinal parasites. Some are visible as worms, while others, like Giardia, Toxoplasma, and Coccidia are not visible without a microscope.

Many of these parasites cause diarrhea and/or vomiting, loss of appetite, weight loss, poor hair coat, anemia (decreased red blood cells), gastrointestinal pain and discomfort, although some animals show no obvious signs. Some of these parasites can be transmitted to people and can cause skin and eye problems, especially in children.

Eggs or cysts are passed in the stool of infected animals and are ingested (swallowed/eaten) by other animals. The parasite then develops and causes disease in the new host. Some parasites such as roundworms and hookworms can be passed from a pregnant dog or cat to her offspring in the uterus or through the milk while nursing. Intestinal parasites can be passed to people and other pets. Children who play in an area where animal feces are present can get infected feces on their hands and may ingest the parasite eggs. Roundworm infection in children may cause serious liver or eye inflammation. A larval (young worm) form of hookworm can enter through the skin and cause skin inflammation and itching.

A microscopic examination of the animal’s stool will usually confirm a parasite infestation.

All animals admitted to the Connecticut Humane Society are given multiple types of deworming treatments during the course of their stay. They are checked for the presence of parasites if they develop any signs of infestation and some infestations require several rounds of treatment to be eliminated. Since tapeworms develop as a result of eating fleas (or occasionally from eating rodents prior to admission to CHS), dogs and cats are treated for tapeworms if the parasite is seen or if they have a history of flea infestation. Re-infestation is possible, even with strict hygiene since many parasite eggs can survive for months or years outdoors.

Avoid contact with areas where animal feces are present, and pick up and dispose of stools deposited by your own pets.

Any sign of gastrointestinal upset (diarrhea, vomiting, loss of appetite) or visible worms in the stool or in vomit should be reported to your veterinarian promptly. A fecal exam should be performed annually to check for the presence of parasites and a monthly preventative should be administered.