Roundworms are parasites that can infect a dog or cat’s intestinal tract, leading to malnourishment. They begin life as microscopic eggs and can grow to several inches in length. The parasites travel through different tissues in the dog or cat’s body at different stages of the roundworm’s life cycle, so they can also affect the lungs and throat of the animal.
Roundworms can be treated effectively with deworming medications, but if left untreated, a severe infestation in the intestines can lead to a blocked digestive system and possibly to death.
It’s important to note that roundworms can also be transferred to humans. Though most infestations in humans will have no effect, rare serious cases can result in eye disease.
The good news is that roundworms, while common, can be effectively eliminated through medications and good cleaning practices before their impact becomes severe.
Roundworms of various types can infect dogs and cats. Toxocara cati infects cats, Toxocara canis infects dogs, and Toxascaris leonina can infect either animal. A dog or cat becomes infected with roundworm after ingesting eggs in infested dirt (like after grooming or cleaning paws and fur after being outside), or after eating a rodent that was infected. An infected pet’s stool will have roundworm eggs in it, so eating infected stool will cause the pet to become infected as well.
Sometimes roundworms can be dormant in pregnant females, and can infect the unborn puppies and kittens. Read more about the causes of roundworm.
Sometimes a roundworm infection will cause no symptoms at all. The parasites may be dormant inside a pregnant female’s body, and only become active after passing to the puppies or kittens in utero, or through nursing milk.
The most common symptom of roundworm is diarrhea, often with worms visible in the stool. Vomiting, a pot-bellied appearance, and lethargy are also common symptoms.
Deworming medicines target the adult roundworms that have attached to the intestinal wall. The worms are anesthetized so they release their bite on the intestines and pass out of the body through the stool. Once in the outside environment, the worm dies. Because some worms may be in different life stages at the time of treatment, deworming medicines may have to be administered several times to be fully effective.
Since roundworms are so common, especially in puppies and kittens, it’s essential to get your new pet checked immediately. Some vets recommend deworming for puppies and kittens whether there are any signs of the worms or not, just to be safe. Read about the common types of deworming medications.
More on Parasites in Pets
Whipworms in Dogs and Cats
This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.