Spring is the time when many “indoor” cats head back outside, even if only for short periods of time. Most of these cats will end up hunting and eating something at some point. Some cats are obvious about this and will leave “presents” at home, while others are very sneaky. (There was one study which tracked cats via GPS, and one of those cats reportedly “never left the porch.” However, this kitty was found to be an active hunter while the owner was out of sight and was always back on the porch by the time the owner came back!) Even cats that don’t go outside can hunt – everyone knows of a cat that has caught a mouse in the house. While hunting is the main route for intestinal parasites, any cat that uses the great outdoors as a litter box can be exposed to eggs. While most healthy adult cats will “tolerate” intestinal parasites just fine (at least, not show any symptoms of infection), they will still shed eggs to other cats, dogs, and humans. Kittens, senior cats and people, and children are at biggest risk of serious disease. While humans are not the definitive host of these feline parasites, we can still become very sick from them. So, what parasites do we need to watch for, and how might we prevent them?

Roundworms are large worms that can be easily seen in your cat’s stool. They look like strands of spaghetti noodles. However, you will not see them in the stool unless there is a very large number of them in the intestinal tract, at which point most animals end up vomiting them up. Roundworm eggs are directly infective, and cats can reinfect themselves and other cats through grooming and sharing litter boxes. Kittens frequently become infected through nursing. Mice are frequent carriers of eggs, as is the environment (outdoor litter box). Humans become infected through accidental ingestion of eggs (poor hygiene, gardening, kids playing in sand boxes, etc.) Because humans are not a definitive host for feline roundworms, ingested eggs will hatch, but the larvae cannot develop into adult worms. This means the larvae will travel through the body until they eventually die. This condition is called larval migrans and can become serious if the larvae penetrate the eye or viscera (connective tissue between the organs). Roundworms in cats can cause vomiting, diarrhea, pot-bellied appearance, poor growth in kittens, and weight loss. Luckily, roundworms can easily be prevented in cats and dogs through the use of monthly deworming.

Hookworms are very small worms that are not easily seen in your cat’s stool. Cats typically become infected through eating rodents; however, the larvae can penetrate the skin. Humans become infected through larvae penetrating the skin. Like feline roundworm larvae, feline hookworm larvae cannot mature into adult worms in people but will migrate through the skin. The tracts they leave are easily visible in the skin and are very itchy. Hookworm infections can cause anemia, severe diarrhea and be fatal in young kittens. Hookworms are easily prevented by the use of monthly deworming.

Tapeworms are large worms that can be seen in your cat’s stool. They look like long strands of thick mucus. More often people will notice the proglottids (infective segments) in their cat’s fur or on places the cat has been sitting. Dried proglottids most resemble small, dried grains of rice while fresh ones are white, moist and will often be moving. The good news is that the proglottids are not directly infective in cats and dogs. They must go through an intermediate host to become infective to our feline friends. There are two main types of tapeworms: those that use fleas as intermediate hosts, and those that use prey items as intermediate hosts (birds, rodents, rabbits, reptiles). The proglottids are, however, directly infective to humans and will typically cause mild gastrointestinal symptoms. In cats, tapeworms can cause vomiting, diarrhea, weight loss and poor condition.

For more information on the types of preventatives available, please call us at 406-728-0022, or schedule an appointment to discuss a plan to keep your feline friends parasite free. Please note that this newsletter only covered the most common parasites. Coccidia and giardia are two other microscopic “parasites” — I use quotes here because their roles in causing disease have come under question in the past few years. Many researches now feel that these organisms are more opportunistic and will only cause or exacerbate diarrhea in animals that are already ill. Finally, for those of you who are interested, there are many pictures of these parasites along with examples of roundworm and hookworm larval migrans in people available online.