Hookworms are intestinal parasites of the cat and dog. Their name is derived from the hook-like mouthparts they use to anchor themselves to the lining of the intestinal wall. They are only about 1/8″ (2-3 mm) long and so small in diameter that they are barely visible to the naked eye. Hookworms feed on the tissue fluids and blood of their host.
The most common hookworms found in cats are Ancylostoma tubaeforme and Ancylostoma braziliense. Occasionally, cats will also become infected with the dog hookworm, Ancylostoma caninum. Cats can rarely become infected by another dog hookworm, called Uncinaria stenocephala.
In general, cats tend to harbor relatively few hookworms when compared to the large numbers found in dogs. Also, the feline hookworms tend to be less aggressive bloodsuckers than the canine species.