Signs your cat may have worms

Clinical symptoms can vary depending on which worm the cat has and sometimes worms can be seen. Long roundworms can be regurgitated and tapeworms can be seen as flat grains of rice at the anal opening.

  • Diarrhea
  • Weight loss
  • Dull coat
  • Vomiting
  • Cough

Dewormer for cats

There are both prescription and over-the-counter dewormers for cats available. Some tablets and pastes should only be given once, others more than once. If you have difficulty getting medicine into the cat by mouth, a spot-on preparation that is dripped onto the skin can be an alternative.

What dose should I give?

Weigh the cat before you buy dewormers as the dose depends on how much the cat weighs.

Deworming of kittens

Kittens can be at risk of getting roundworms through their mother's milk. The breeder usually deworms the kittens repeatedly during the kittens' first months of life. The mother cat is also dewormed at the same time to avoid re-infection of the kittens.

Deworming of outdoor cats

Many outdoor cats are skilled hunters who like to catch everything from mice to small birds. If you know that your cat likes to hunt and eat mice, rats or voles, you should keep an eye out for worms. By eating small rodents, your cat can ingest both roundworm and tapeworm larvae.

A Swedish study carried out in 2015 showed that around 20 percent of outdoor cats were infected with roundworms. This means that routine deworming may be relevant, especially during the time of year when the cats are most active and catch prey.

If you are unsure whether your cat needs to be dewormed, you can ask your vet to take a sample of the cat's faeces or buy a kit that you can use yourself.

Deworming of indoor cats

The risk of an indoor cat getting sick from worms is very small if it was dewormed as a child and was then strictly an indoor cat. Therefore, indoor cats are rarely dewormed. If you are considering deworming your indoor cat, you should first take a stool sample.

Take a stool sample before deworming

Try to only deworm against the type of worm your cat has to reduce the risk of resistance in the parasites. You can buy a kit intended for taking stool samples, the sample is then mailed to a laboratory that analyses the sample to detect roundworm eggs. Tapeworms can be missed in tensile tests, deworming must take place when you can see them. In case of illness, the vet can take a stool sample or alternatively recommend sampling which can show other, more unusual parasites.

Parasites in cats

The most common parasites in outdoor cats are roundworms and tapeworms (Taenia taeniformis). Giardia Intestinalis is the most common parasite in indoor cats, but Coccidia (Isospora) and Tritrichomonas fetus can also occur.

Tapeworm in cats

Tapeworm (Hydatigera taeniformis) is common in outdoor cats. Cats can become infected by eating mice, rats and voles. Tapeworms are not transmitted directly between cats. Symptoms of tapeworm can be tapeworm tracks in the stool or crawling around the buttocks, on the tail or crotch.

A stool sample cannot always show whether a cat has a tapeworm or not. Extra attention must be paid to a cat that has once had tapeworms. Outdoor cats can easily become re-infected and often get tapeworms again within three to four months.

Roundworm in cats

There are two species of roundworm, the cat roundworm Toxocara cati and the roundworm Toxascaris leonina. Roundworms are detected through a stool test. Adult roundworms can sometimes be seen in the faeces and in some cases a cat may vomit up worms.

Roundworm is transmitted via small rodents and infected female cats can infect their young via their milk.

Frequently asked questions about deworming