How does my cat get intestinal parasites?

Probably the most common method is what's called a fecal-oral route. And yes, it's exactly like it sounds. They have to ingest feces orally to obtain it. And let me be more precise. It's not just any feces; it’s the feces of an infected animal. And in many cases, those fecal eggs or those parasite eggs in the feces have the larvae for a day or two before they become infectious. It's not a hard thing to do. I mean, it happens all the time. And it's not always as deliberate as the cat walking up and eating a pile of stool. I know that sounds disgusting, but they do it. Especially dogs. But it can be as simple as they just stepped in it.

Maybe they share the same litter box as a housemate or littermate. And that animal has it. They go in the same litter box. They're scooting around in there, and they get some on their paw. Well, what's a cat going to do? The first thing that cats will do when they get anything on their body is they're going to stop, and they're going to lick it off. They're going to groom themselves. So, boom, you just got infected that way. So that is the most common reason.

The only exception I would give to those, if we're talking about all the intestinal parasites, is tapeworms, and that’s something we commonly see. The most common thing that we see is dipylidium caninum. That's a tapeworm from fleas. So they have to ingest a flea. Not feces, but a flea. The other type of tapeworm is echinococcus, and the last name is granulosum, I think. But that is something that they usually get from eating the host animal, which is mice. So sometimes you'd have a mouse or cat, maybe a barn cat, something like that. And they ingest a mouse that is happening to harbor this type of tapeworm; they can get it that way.

The most common types of parasites - roundworms and hookworms - are pretty ubiquitous in the environment. You can find them almost anywhere. And their eggs are super hardy. There have actually been a couple of crazy people that have seeded yards with roundworm eggs and then used a flamethrower to completely destroy the yard, and the roundworm eggs were still viable at that point, so that gives you an idea of how hardy they are. You can find them everywhere. Walking around outside or even being exposed to the dirt on your shoes can cause potential exposure to these sorts of parasites.

Other worms, like tapeworms, are only transmitted through flea infestations. When your cat is grooming themselves and ingests a flea that has tapeworm larvae, that's how that they would potentially become infected there. Other less common intestinal parasites like Giardia or coccidia are typically transmitted pet to pet or through contaminated water sources. And one thing to think about with kittens specifically is that hookworms and roundworms can be passed through the placenta while they're in the womb or can even be transmitted through milk. That’s why it’s vital to do regular deworming of queens as well as kittens.

Cats can get intestinal parasites, and they can be transmitted in utero. When the kitten is still in the mother's uterus, they can be passed through the placenta, or after they're born, they can pick them up from other cats in the household, the mom, or from a humane society. They can also get internal parasites when they go outside, and they're out and about, as they can pick them up from other cats.

Many times it's from either ingesting fleas that have the tapeworm eggs, or from being in a litter box that has otherwise been contaminated by a cat. Kittens are especially a lot more prone to having those intestinal worms that they can spread around.

Some cats go in and outside in multi-cat households and transmit parasites through fecal contamination. So even if the feces is picked up, animals still step in it and we get fecal material on our shoes. We can bring it into the house, get on the pet skin, and when they're grooming, they get infected. They get exposure even without gross fecal material being apparent. They also get parasites from the soil, so they'll get exposed if they are indoor-outdoor cats. We see intestinal parasites in indoor-only cats as well because fecal material can be transported in microscopic amounts so easily. Those are the common ways that cats get exposed to intestinal parasites. Kittens specifically are the most susceptible to these worms, and they often get these parasites from their mother. We'll sometimes see young kittens with multiple worms, depending on the situation with the mom and the litter.

Most cats get intestinal parasites through fecal-oral transmission, meaning they get exposed to fecal material containing eggs that are then ingested by your cat. Another way is through parasite transmission, such as a flea carrying a tapeworm larva. If your cat ingests that flea, the chances of getting an intestinal tapeworm are high.

Cats can acquire parasites when they clean their feet after using the litter box or going outside. The parasites could possibly get picked up during this process.