What are worms in dogs and cats?
Worms or helminths are internal parasites that drain pets of blood and nutrients. Dogs and cats get worms that can be classified by shape into round or flat. Three types of round-shaped worms (nematodes) live in pet intestines: roundworms, hookworms, and whipworms. Two types of flat-shaped tapeworms (cestodes) live in pet intestines and other organs, including the liver: echinococcus and taenia. Dogs commonly get hookworms, whipworms, roundworms, and tapeworms. Cats commonly get roundworms, hookworms, and tapeworms, but not whipworms.
Pets can also get lungworms, esophageal worms, bloodworms, kidney worms, liver flukes, and intestinal protozoa. The most common pet worms are roundworms, and hookworms. Heartworms (Dirofilaria immitis) are not intestinal parasites but are parasites that live in the heart. Heartworms are not spread like regular intestinal worms, but are spread by mosquitoes. They infect both cats and dogs and can cause death.