Mary Allen
Almost every cat owner has seen fleas or ticks. No wonder, they are visibly crawling around in the fur. But annoying roommates can also settle inside the cat.
When the former farm kitten Socrates was about six months old and his castration was imminent, his owner’s worries grew. The young tomcat had become thinner and thinner, his fur had lost its shine, he was often tired, and there was also something wrong with his digestion because suddenly there were strange, mushy heaps in the litter box. One morning, she had just come out of the bathroom when the animal lover saw a sight that frightened her deeply. Socrates threw up, and on the floor in front of her, between some bits of food, she saw louder, quote, “white, long, moving spaghetti.” A short cry of disgust escaped the woman. She immediately made her way to the vet.
What the cat owner saw were parasites of the cat that settle inside the body. In this case, it was roundworms, with which, depending on the study, between 25 and 60 percent of velvet paws in Switzerland are infected. But how does this happen?
The Parasite Travels Throughout the Body
The roundworm undergoes a tricky development in order to get into the cat: roundworm eggs are excreted with the feces of an infected cat – in unimaginable quantities because each female roundworm produces up to 200,000 eggs every day. These continue to develop in the environment when the outside temperature is mild, and larvae grow in them. Among other things, they are ingested by mice. If a cat eats a mouse that has roundworm larvae in it, these live on in the cat after the mouse has digested them.
Another possibility of infection is the smear infection. The egg with the larva enters the cat’s body directly, for example via a blade of grass that has been nibbled on. If the cat has never had a roundworm infection before, an impressive journey of the parasite begins in the animal’s body. Once in the cat’s small intestine, the larvae hatch from the eggs. They penetrate the mucous membrane of the intestine. From there they crawl into the blood vessels that run towards the liver. There they stay for a while before they reach the lungs after an intermediate stop in the right heart.
This is not the end of the body migration: the roundworm larvae migrate up the trachea into the pharynx and can be swallowed with the saliva back into the gastrointestinal tract. Only now do the larvae develop into adult worms, which can grow up to twelve centimeters long. From then on they remain in the intestine and diligently produce eggs that are released into the environment with the cat’s feces. The cycle starts over.
As if this massive way of spreading wasn’t enough, the cat roundworm has another trick up its sleeve: larvae can settle permanently in many parts of the body, for example in the teats. So it happens that newborn kittens become infected with roundworms as soon as they drink their first milk. But be careful: Whether it’s the milk, the mouse, or the blade of grass – symptoms like Socrates only develop in cats that are particularly badly affected or are already weak. The infection often goes unnoticed.
The Worms are no Threat to Us
In addition to roundworms, tapeworms are an important group against which cats should be treated regularly. Infection also occurs by eating mice. And they also settle in the intestines, which in the worst case can lead to intestinal obstruction. Unlike roundworms, tapeworms do not lay eggs that are excreted in the feces but shed their own body segments filled with eggs. These segments actively migrate out of the cat’s anus to the outside. This may sound familiar to one or the other cat lover: It is not uncommon for a small, light-colored worm, about one centimeter long, to crawl somewhere in the fur on the cat’s rear end or tail. Sounds repulsive, but poses no health hazard to bipeds.
The infestation can have serious consequences for the cat. Usually, it is a specimen called Taenia taeniaeformis; up to 25 percent of cats are said to be infected. The tapeworms have suction cups and hooks at the head end. This allows them to stick to the intestinal mucosa. They can grow up to half a meter long in the cat. There are cases when they even have to be surgically removed.