There are several types of worms that can infect cats, and even if your cat is indoors most or all of the time, they can still become infected. Roundworms, hookworms, tapeworms, heartworms and to a lesser extent, whipworms, can all be passed to cats from another source. It is important for cat owners to learn the ways in which worms are passed from an outside environment to their house cats, as this will ensure they use preventative measures.
Worms Transmitted From The Cat's Mother
If a pregnant cat is infected with worms, she will pass the worms to her kittens. The worm larvae can be transmitted while the kittens are still inside the mother's uterus, and can also be passed to the kittens after birth through the mother's milk during nursing.
Worms Transmitted by Mosquito
Heartworms are transmitted by mosquito bite, the worm larvae passing into the cat's bloodstream as the mosquito bites and feeds on the cat. Mosquitoes enter the house through doors and windows that are constantly opened and shut. Once infected, there is no treatment for heartworms for cats, so preventative measures such as monthly heartworm medication should be given.
Worms Transmitted by Fleas
Tapeworms normally infect house cats when they ingest fleas that are infected with the tapeworm larvae. The tapeworm will then grown inside the cat and begin to drop segments out of the cat's anus, which then can ensure that the cycle repeats itself.
Worms Transmitted by Ingesting Infected Animals
House cats can become infected with worms when they eat tissue from infected animals such as mice or rats. The smaller animals become infected outside, and when they venture inside the house, the cat kills and eats them, which transmits the worms. Cockroaches are even known to carry some types or worms such as tapeworms, and ingesting the roach can infect the cat as well.
Worms Transmitted by an Outdoor Pet
An outdoor pet such as a dog or another cat can walk through an area that is infested with worm eggs, and then carry the eggs into the house. The eggs will often stick to the pet's fur on its feet, and then fall off once inside the house. The house cat inadvertently steps on the eggs, and ingests the eggs while grooming itself. Once ingested, the eggs will hatch in the cat's gastrointestinal tract, and the cat becomes infected.