Roundworms are invasive parasites that can infect pets and even people if caution is not taken. A healthy, clean environment is the best way to prevent an infestation, and several medications are available for treatment if an infestation does occur. Roundworms can grow several inches in length, more than double their size in about a week and lay hundreds of thousands of eggs in a single day.
Roundworms come in several types. Three include Toxocara canis, Toxocara leonina and Toxocara cati. The first two infect dogs and foxes, with the leonina expanding its reach to also include other carnivores found in the wild. Toxocara cati, as the name suggests, infects cats. All three worms look similar, but they can be transmitted in slightly different means. All three can infect an animal if it eats the worm eggs or another animal, such as a rat or mouse, which is infect with the worms. The canis and cati varieties can also be passed along from the mother dog or cat to her puppies or kittens through her milk. The canis variety can also be transmitted from the mother dog to her unborn puppies through her uterus.
Roundworms are smooth, cylindrical and a light iridescent color. They have no visible eyes or scales. Adult roundworms can grow up to 4 inches long. The worm may enter a dog, for instance, in the post-larval stage at less than an inch long and grow to 2 inches long in as few as 10 days.
A roundworm will grow in the animal's digestive tract, feeding on nutrients. Because it is taking nutrients away from the host, the animal may end up with a lackluster and sparse coat. The pet may develop a pot belly. In the most severe cases, worms can block the digestive tract and kill the animal.
An animal infected with roundworms should be treated immediately. Several medications, such as pyrantel pamoate or Nemex, are available for roundworm treatment. Some come in both liquid and tablet forms and dosages are based on the pet's body weight. Pets should be given at least three to four dosages, one each day, to eradicate worms and then be checked by a vet to ensure the worms are gone. Some of the medications can also be used as a preventative, especially before breeding and then again about a month later. Both the mother animal and the offspring should be treated. Other preventative measures include keeping pets away from potentially infected areas, such as unclean kennels, polluted waterways and public pet parks. Rats and mice often carry roundworm, so exterminating them from the property is another way to keep the pet safe. Clean kennels and other areas with bleach and water, pick up waste immediately and have pets checked at least annually at the vet, or immediately if symptoms occur, to further keep them healthy.
Roundworms are prolific breeders and can quickly infect a pet so the animal is passing thousands of eggs each day. A female adult roundworm can lay up 200,000 eggs in a day. Humans can get roundworms when the inadvertently ingest the eggs. Roundworm infection in humans can cause nervous system damage and blindness.