Effects of Worms in Cats

Mama cats can transfer worms to their kittens.
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Most pet parents face a worm infestation at some point—of their cats, that is, not themselves. Frisky felines pick them up from ingesting infected feces, vomit or rodents—sorry for the gross-out. But they're not just gross: worm infections can lead to other health issues.

Short-Term Effects

When a cat develops worms, the infestation primarily affects the digestive tract. That's because worms, such as tapeworms, roundworms and hookworms, live in the intestines, and stomach worms reside in the—you guessed it—stomach. The result is vomiting, diarrhea and appetite loss. Some cats develop a tummy that looks potbellied and others' coats become dull and ragged. You might also find blood or mucus in the stool and vomit. In cases of hookworm, the stool has a dark, tar-like look. Finally, check the color of your cat's gums. If they're pale, it could be because of the worm infestation.

Long-Term Effects

Left untreated, worms can have devastating effects on a cat's health. In some cases they can be fatal. When cats lose too much blood due to worms, it causes anemia. The kitties become weak and their bodies don't have enough juice to fight off other infections. For kittens, this can be lethal. If too many roundworms get into the intestines, the effect is a blockage—also potentially lethal, especially for kittens. Severe infestations that cause chronic diarrhea and irritation can lead to a prolapse—when the rectum slips out of place, looking like a fleshy tube protruding from the cat's rear end. This must be treated immediately, or death will result.


If you don't want to deal with the effects of worms in cats, there's a simple solution: prevention. Have your cat wormed early, even as a kitten, since infected mama cats pass worms on to their kittens. Keep your living area clean to prevent contamination, and keep kitty inside so she doesn't snack on any infected critters. Fleas and rodents can both be infected and give your cat worms if she eats them. If it's too late to prevent the infection, it's time for a trip to the veterinarian. He can prescribe a safe medication to rid your cat's system of worms. This should clear up any diarrhea, vomiting and other associated effects. (Keep in mind, though, that some infestations cause few or no visible symptoms.) If the infestation has caused more advanced problems, such as anemia or dehydration, the veterinarian may want to give your cat fluids to get her healthy again. If other bacterial infections have occurred, it may be time for an antibiotic. Blockages and prolapse require surgery to fix.

Warning Signs

Since anemia, blockages and prolapses can be fatal, you need to know what symptoms to look for. You probably already know that cats are fantastic at masking pain and injury, so you may have to do some detective work. For anemia, those pale gums are a primary sign there's a problem. Kitty may also seem extra tired, and uninterested in playing his usual games or eating his regular meals. If his breathing speeds up and he begins to pant with his mouth open, it's vet time. Keep a close eye on Kitty while he's in the litter box. If he strains to go but nothing comes out? There could be a blockage. If he meows as if he's in pain? Again, there's a chance of blockage. And all that straining can lead to a prolapse.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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