What is the Most Common Internal Parasites in Animals?

According to the University of Florida research study on mosquito-borne heartworm, 100 percent of dogs exposed to infective larvae become infected with heartworm if the dog is not protected through medication. Pet owners protect their animals from parasites like heartworm with seasonal medications. Not all parasites can be protected against, and not all animals have the same types of parasites. Livestock, horses and other animals can also suffer adverse affects from parasites, which lead to incapacity and even death.

  1. Livestock

    • Young calves younger than 1 are most at risk of suffering from internal parasites, most often worms. Young sheep are similarly at risk for infections. Specific forms of worms, such as strongyles, are common in cattle. The eggs infect young calves that have not yet built up an immunity to the parasite. Rainfall and temperature can play a role in the infection of cattle with worms, with an ideal temperature being less than 80 degrees and above 60 degrees. Veterinarians have an arsenal of medications available for cattle to help eliminate the worms, and they will decide on the correct medication depending on the extent of the worm growth and the age of the animal.

    House Pets

    • Worms are also the most common internal parasite among household animals. Roundworms are one of the most common types of worm parasite in household pets such as dogs and cats. Tapeworms are a more advanced intestinal worm found in dogs and cats that have ingested an infected flea. Visually noticing small worms in the stool of the animal is how veterinarians often diagnose tapeworm, followed by stool sampling. All these parasites are commonly treated with antibiotics. It is essential to eliminate the parasites before they infect the heart and kill the animal. Puppies and kittens are most vulnerable to parasite infections because they have not yet built up an immunity and often don't have the strength to fight off the infection or survive the medication used to eliminate the infestation of parasites.

    Horses

    • Strongyles is also common in horses because of their large stature. Roundworms also are extremely common. There are three species of strongyles including strongylus vulgaris, strongylus endentatus and strongylus equinus. Horses pass larva in their feces and contaminate the pasture, which other horses feed from. If one horse has a form of strongyles, all horses in the pasture need to be treated. This can become extremely expensive for horse owners. Strongyles larva can survive up to 31 weeks and withstand almost any winter conditions, making this form of parasite hard to extinguish fully without continued attention and medication to the animals.

    Other Animals

    • Any animal, including humans, is at risk of becoming infected by any number of internal parasites. Ants can surcome to the effects of parasites. Ophiocordyceps unilateralis is a debilitating parasite known to attack zombie ants and kills them in a visible location, where other predators can eat the ants. Other animals such as monkeys, zebras and birds are all susceptible to tapeworms.