Cats and Worms

Worms The most common intestinal worms that cats get are called roundworms and tapeworms. Most infected cats do not show signs of having worms but heavy cases of worms can cause weight loss, vomiting and diarrhoea, irritation around the anus and failure to thrive. Some worms can also be passed on to humans and on rare occasions can be a cause of serious human disease. For these reasons, regular treatment of cats and kittens to prevent or eliminate worms is very important. Routine  treatment for worms is recommended throughout a cat’s life.

Roundworms Intestinal roundworms are the most common intestinal parasites in cats and occur in cats of all ages throughout the world. The two common roundworms of cats are called, Toxocara cati and Toxascaris leonina. Eggs from these worms are passed in the faeces and can remain viable in the environment for several years. These eggs can infect cats in two ways. First, a cat may eat eggs directly from a contaminated environment (by eating an infected cat’s food for instance).  Secondly, if your cat hunts, always presume they do, and their prey has eaten  worm eggs  (eg, a mouse or rat) these act as ‘intermediate hosts’ and pass on the infection to your cat when it eats the prey.

Hookworms are a type of small intestinal roundworm found in most countries throughout the world. These worms can cause damage to the lining of the intestine where they attach to the surface, and this may result in weight loss, bleeding and anaemia. Common cat hookworms include Ancylostoma tubaeforme, and Uncinaria stenocephala, but other species occur in some countries.

Tapeworms are generally long flat worms composed of many segments. Mature segments containing eggs are released from the end of the tapeworm and are passed in the faeces. These segments often resemble grains of rice and can sometimes be seen on the hair around the anus of the cat, in the faeces and on the cat's bed.

To complete their life-cycle, all tapeworms require an intermediate host to first eat the eggs from the environment, and then the cat will become infected by eating the  host. Animals that act as intermediate hosts vary depending on the species of tapeworm Dipylidium caninum is transmitted to cats by fleas. The immature fleas larvae ingest the eggs of the worm, but infection is then passed on to a cat when it swallows an infected flea during grooming. It should be assumed that any cat infected with fleas also has Dipylidium caninum (and vice versa).

Taenia taeniaeformis is passed on to when they eat small rodents (rats and mice), the rodents having eaten eggs from the environment. This infection occurs very commonly in cats that hunt

Worming your cat

Roundworms are extremely common in kittens, and as kittens can be infected from the mother’s milk it should be assumed that all kittens are infected and worming should be started at a young age. Common recommendations are to:

Treat kittens for roundworms every 2 weeks from 3 weeks of age until 8 weeks of age, then monthly to 6 months of age. Treat  cats over 6 months old every 1-3 months.

Tapeworms are only usually a problem in older cats, unless a kitten also has fleas. Adult cats (greater than 6 months of age) should be treated every 1-3 months with a product that is effective against both tapeworms and roundworms. A product active against tapeworms should also be used in kittens that have flea infestations.