Written by Justine Lee, DVM, DACVECC, DABT
Was your cat just diagnosed with “worms?” As a veterinarian, I see a lot of gross things in my profession—and worms in cats and dogs top the list.
Previously, we talked about the numerous types of worms (such as heartworm) that can affect cats. That said, the most common are those that affect the gastrointestinal tract: tapeworms, roundworms, and hookworms. Gastrointestinal parasites occur in cats that have not been appropriately dewormed, and are very common in young kittens. As gastrointestinal worms feed on nutrients that your cat should be getting, they can result in chronic wasting, pain, discomfort, and weight loss in cats. Also, they can spread to humans and other pets, while contaminating the environment for a long time! For that reason, it’s important to learn about worms in cats and how to treat them.
Tapeworms in cats
Tapeworms are caused by a Cestoda worm (e.g., Taenia, Dipylidium caninum, Echinococcus, Mesocestoides, etc.)and are long, flat worms that attach to your cat’s gastrointestinal tract. Pet owners may notice small pieces of tapeworm breaking off and getting stuck to the perianal area, tail, or feces in the litter box. This often looks like small, white pieces of rice (or sesame seeds). This can cause intense itching in your cat, including excessive grooming and also dragging the rear end across the floor or carpet. Rarely, these tapeworms (specifically Echinococcus) can be very harmful to humans, so treatment is always important. Treatment typically includes both a flea medication and several doses of a dewormer.
Roundworms in cats
Roundworms, also known as ascarids or nematodes, are caused by the Toxocara worm. They are the most common gastrointestinal tract in cats, affecting over 60,000 cases in the United States last year. Almost all cats—at some point in their lives—will be infected with roundworms. Because roundworms are so prevalent, they are easy to spread and harder to control. These look like long, white or light brown noodles and can grow to be several inches long. Roundworms spread to cats when cats ingest earthworms, birds, mice, or other small animals that carry the roundworm larvae (e.g., the young worm stage). They can also be spread from a mother’s milk to the kitten. Treatment typically requires multiple doses of a dewormer. Roundworms are important to treat, as they can also result in harm to humans. Children are especially at risk, and rarely can develop blindness (called ocular larval migrans) from roundworms.
Hookworms in cats
Hookworms, while less common, can be deadly to cats. About 10,000 cases were identified in cats in the United States last year, with a predominance in warm southern states. Hookworms also attach to your cat’s intestines, living off your cat’s blood. This can result in a life-threatening anemia, and can cause death in young kittens. I’ve seen young kittens need blood transfusions to save them. Treatment also typically requires multiple doses of a dewormer. Hookworms are important to treat, as humans can develop cutaneous larval migrans from hookworms.
What are signs of gastrointestinal worms in cats?
Clinical signs of gastrointestinal worms in cats include:
- Having a round, potbellied belly
- Not eating well
- Perianal irritation
- Visible worms in the rectal area or feces
- Blood loss into the intestinal tract
- Dull hair coat
- Weight loss
- Presence of worms in the vomit
What cats are at risk for worms?
Cats that go outdoors are more at risk for getting gastrointestinal parasites, along with stray or feral cats and young kittens (as the worms can pass across the placenta). Also, cats living in the south or in warmer areas of the United States may be at higher risk, as these states don’t have a hard frost that may kill parasites.
How do cats get worms?
Cats typically get gastrointestinal worms from being outside and hunting. Depending on the type of worm, the “host” of the worm (those that spread it to your cat) can vary. Cats get tapeworms by hunting and ingesting mice, rats, birds, and rabbits. This is similar with roundworms and hookworms, although kittens can also get these gastrointestinal parasites through the mother’s milk when nursing.
Please note that—specifically for tapeworms—cats can get tapeworms through flea infestations. That’s right—fleas! Adult fleas ingest tapeworm eggs, and can pass the larvae onto the cat (when your cat grooms). If your cat grooms a tapeworm-infected egg stuck on a flea larvae, your cat will get tapeworm. So, whenever your veterinarian diagnoses your cat with tapeworm, a flea infestation is highly suspected—that’s why your veterinarian will insist on treating your cat for fleas at the same time.
How does my veterinarian diagnose if my cat has worms?
A simple fecal test can diagnose gastrointestinal parasites. When in doubt, always bring a fresh fecal sample to your veterinarian for analysis annually, and when the kittens are being weaned. A physical exam is also important to look for the presence of fleas (for tapeworm), and to make sure your cat isn’t having any ill effect from the parasites. Test results are typically back within 24 hours. If your cat is having chronic diarrhea and not responding to a dewormer, your veterinarian may need to do several additional types of fecal tests (which may include a Giardia test, fecal culture, etc.).
How do I treat worms in my cat? And how do I keep my cat safe?
It’s important to treat your cat as soon as he or she is diagnosed with gastrointestinal parasites to prevent damage to your cat’s body and to prevent accidental spread to humans. The best way of treating gastrointestinal parasites is by parasiticides (e.g. medications that kill parasites). Treatment is typically quick and effective. Your cat will need to be treated several times to ensure that the eggs, larvae, and adult worms are killed. For example, with roundworms, kittens need to be treated every 2 weeks between 3-9 weeks of age. Make sure to finish the full course of medication from your veterinarian to ensure that the parasitic infection is treated. To prevent tapeworm infestation, it’s imperative that you also prevent a flea infestation in your cat.
Once your cat has been treated, you should keep your cat safe by keeping them indoors (to prevent hunting and scavenging) and making sure to use preventative measures. When it comes to preventing a parasitic infection in your cat, talk to your veterinarian. There are several safe choices to protect your cat from multiple types of worms. If your cat is indoor-only, he or she may only need a once-a-year dewormer. If your cat is indoor/outdoor, a monthly preventative may be necessary.
What’s the prognosis if my cat has worms?
Thankfully, the prognosis is excellent once your cat is appropriately treated with the correct dewormer or parasiticide.