Common Parasites Found In Dogs And What To Do

March 23, 2023

Owning a dog is one of the most fun, rewarding experiences we can have. Puppies are amazing, training is a hilarious process, and a grown-up best friend doggy is one of life's precious gifts. The thing is, sometimes just going on walks and being in nature exposes dogs to other animals, insects, and environments that could be harboring something that will make them sick. We want the best for our pets, so it's important to know what types of parasites, ailments, and infections we might be facing together during their lifetime. This way, we can be prepared and ensure a healthier and happier experience for our pets!


Heartworm is one of the most common worries of veterinarians and dog owners alike, but it is completely preventable. It's pretty common for most dogs in the United States to take medication to ward off the disease, which is caused by being bitten by an infected mosquito and does not transmit to humans. The medication, which is either a monthly pill, monthly topical or bi-annual injection, is inexpensive and much cheaper than treating and curing heartworm itself. Once bitten (and again, heartworm cannot be passed from dog to dog), the worm's larvae will grow inside the dog and potentially develop into hundreds of worms in about six months. These worms can be several inches long and can live up to five to seven years. Imagine the space that would take up inside a dog! It inevitably has serious health consequences and will eventually become fatal. If your dog does become infected, treatment is available in the form of x-rays, blood and lab work, and several series of injections based on the infection's severity.

Fleas And Ticks

Fleas and ticks are facts of life for dogs. Sometimes we don't realize there is an entire universe of life out there on the insect and even microscopic level. Some things can be benign, but fleas and ticks are two examples where tiny things can cause discomfort and illness. For example, fleas bite your dog and feed on their blood, which can be dangerous in terms of actual blood loss, especially for puppies. These bites can also cause an allergic reaction, itchiness, irritability, abrasions from scratching, infections, and more. Unfortunately, ticks also feast on blood and are looking to your dog's nice warm fur coat for the perfect place to set up a home. Prevention and observation are critical here. Watch for signs of lethargy or excessive scratching, and be sure to check over your dog's entire body after every romp outdoors. If you do find evidence of either insect, do not panic. There are plenty of topical medicines that can help with fleas, while ticks need to be physically removed from your dog's skin. Don't forget to disinfect the site and your hands afterward.


Ringworm is a bit of a misnomer because this isn't actually a worm (unlike heartworms and tapeworms). Ringworm is actually a fungus, so named for its characteristic ring-like shape that presents as raised red bumps in a circular pattern. In dogs, since they have fur, you will notice actual hair loss in circular patches and a general disturbance in their coat as the fungus spreads around. Ringworm is spread by direct contact with the infected area, so a dog might spread it around itself and to other pets in the house. Humans can also develop ringworm. Luckily, the fungus is easily treated with topical or ingested medication. Simply use an over-the-counter anti-fungal cream, or see your veterinarian for a prescription shampoo, cream, or ointment. Remember, this can spread easily, so you need to stamp it out aggressively.


We've likely all heard of tapeworms, and we know they are the stuff of nightmares! Tapeworms are indeed a parasite, and they live in intestines. A typical way of acquiring them is your dog ingests a flea that is harboring tapeworm eggs, either during grooming or exploration. Once eaten, the eggs settle and mature in your dog's intestine until they hatch. These sneaky guys have a virtually unlimited food supply since they snack on everything that passes by, and the cycle continues as the eggs travel to your dog's stool and spread even more. Another example of a parasite that is easy to treat, tapeworms are usually easily killed by a drug called praziquantel, which is applied topically or ingested. The most unfortunate part of the treatment process is providing a stool sample to your vet.

Ear Mites

Ear mites are tiny parasites that hop onto your pup when in close contact. They set up shop in your dog's ear canal and feast on oils and ear wax. If your dog is itching their ears uncontrollably, start with a visual inspection yourself. Ear mites are white and the size of a pinhead, and they will be moving. It's possible to see them with and without a magnifying glass, but a veterinarian will be able to take skin scrapings and determine with certainty under a microscope. In terms of treatment, it is easy to get a prescription for a topical cream that you apply for ten to thirty days to kill the mites. However, there are also newer treatments that can zap them with one application. Inquire with your vet to see what they offer.

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