What is Intestinal Worms?

Intestinal worm infestations (helminthiasis) occur when parasitic worms live in the intestine; the most common in dogs and cats are hookworms (which feed on blood), roundworms (Toxocara species, most common in puppies and kittens), and tapeworms (Dipylidium caninum, transmitted by fleas). Infection occurs through ingestion of eggs or larvae present in soil or contaminated feces, through the mother's milk (in the case of newborns), or by ingesting infected fleas.

Symptoms vary depending on the type and burden of worms, including diarrhea (sometimes with blood or mucus), vomiting, a bloated belly, weight loss despite a normal appetite, a dull coat, itching around the anus (the pet may "scoot" on the ground), and, in puppies and kittens with heavy infestations, anemia and stunted growth. Some worms, such as tapeworm segments, can be seen as small, moving white segments in the feces or near the anus.

Several species of intestinal worms are zoonotic, meaning they can infect humans, especially children who have more contact with contaminated soil. Diagnosis is made through a fecal exam, and treatment with specific deworming medication is usually effective and should follow a regular prevention schedule. See a veterinarian if you notice visible worms in the feces, a bloated belly in a puppy or kitten, persistent diarrhea, or unexplained weight loss.