Intestinal Parasites and the Importance of Deworming

95% of kittens are born with intestinal worms! These parasites can cause vomiting, diarrhea, weight loss, stunted growth and even death. Some kinds, especially roundworms, are also transmissible to humans.


There are 10,000 cases of animal parasites causing disease in children every year in the United States.
Internal parasites are diagnosed by having a fresh stool sample examined under a microscope by a Certified Veterinary Technician here at the veterinary hospital.

Intestinal Parasites are Diagnosed by Stool Samples

This should be done as part of a health exam when you obtain a new kitten or cat, and on a yearly basis as part of your cat’s annual health exam and vaccinations. Try to collect the freshest sample you can and keep it refrigerated until you can bring it to the veterinary hospital. Stool samples will keep up to 24 hours if kept cool (NOT FROZEN). The presence of litter will not affect testing.

So that you may better understand the problems internal parasites can cause and what
signs to look for, we have included a short description of the five most common types of
internal parasites.

5 Most Common Intestinal Parasites

Round Worms are the most common type of worm. They are 2-3 inches long and resemble strands of spaghetti. They live in the small intestine and may cause vomiting, diarrhea, and weight loss. This parasite is most commonly transmitted via the stools of other cats or dogs. Mother cats can also pass these worms to their unborn kittens. They pose the most significant risk to human health.

Hook Worms are small, fine worms that attach to the walls of the small intestine and live by sucking blood from the cat. They cause severe diarrhea, which may be bloody, and anemia, especially in
kittens and young cats. Hookworms are usually transmitted by contact with infected stools of other cats or dogs, or via the uterus or mother’s milk. They can be transmitted to people through the soles of bare feet.

Tape Worms also live in the small intestine, where the head attaches to the intestinal wall and produces a chain of segments. Mature segments containing eggs are passed with the stool, or may be seen around the rectum. They resemble small grains of rice. They may be acquired through the ingestion of rodents or birds or, more commonly, through the ingestion of fleas. Flea control is essential to control tapeworm infestation. It can be difficult to detect them on fecal testing.

Coccidia is one-celled protozoal parasites, more like bacteria rather than “worms.” Kittens can pick these up from their mother and they can also be acquired by eating rabbit or other wildlife droppings. They are treated with antibiotics.

Giardia are also protozoans. They are very difficult to pick up on a regular stool check. Antibiotics or special wormers kill them but they are difficult to eradicate completely and often flare up with stress or other intestinal problems. They are contagious to humans and cause vomiting and diarrhea in both people and pets.

If a stool sample is positive for parasites, your veterinarian will prescribe an effective dewormer and set up an appropriate cat deworming schedule for you to follow to ensure the eradication of all parasites. We usually recommend cat deworming twice, two weeks apart, however, this will vary with the type of parasite found.

Please weigh your animal before picking up any dewormer, to ensure that the proper dose is given.

A stool sample should be checked again 4 to 8 weeks later, and again possibly 3 months later to ensure that your pet is not being reinfested by his or her environment. Clean the litter box daily as well. Even if fecal testing does not detect intestinal parasites, because intestinal parasites are common in young kitten and puppies and there is the potential for human consequences, the Center for Disease Control recommends deworming of all puppies and kittens at least two times.