Broadly speaking the main types of worms that cause problems in the cat are:
- Roundworms: there are two main types, Toxocara cati and Toxascaris leonina.
- Tapeworms: Dipylidium caninum and Taenia taeniaformis are the main examples in the UK.
Roundworms are free-living within the gut. In kittens, large numbers can stunt growth, create serious digestive upsets and cause flatulence. Kittens with heavy worm burdens often have a 'pot-bellied' appearance. Roundworms spread directly from cat to cat via eggs in the faeces. Toxocara cati can also be spread from mother to kitten via milk.
As with the intestinal roundworms, these rarely cause problems in adults but in kittens tapeworms can be responsible for digestive upsets, intestinal blockages and stunted growth. The tapeworms require an 'intermediate host' in order to spread, that is, they do not spread directly from cat to cat. Dipylidium caninum is spread by fleas. Taenia taeniaformis is passed to cats from small rodents and is therefore seen in cats that hunt.
Treating for worms
Worms can affect cats at any age and some of the worms your cat can carry cause disease in people, especially children. You should worm your cat at least every 6 months, ideally every 2-3 months, with a reliable worming product. Most worming products do not have any residual activity, so whilst they eliminate any worms present at the time they are given, there is nothing to stop your cat picking up another worm soon after. Speak to your vet if you wish to discuss worming protocols in more detail.