Parasite Control

From mange and fleas to roundworm and heartworm, there are dozens of parasites that your pet is at risk of acquiring. Most pet owners are aware that depending on the parasite, it can be a serious problem. In the Ottawa region, we have plenty of mosquitoes and ticks, making diseases like heartworm and lyme a danger to the dogs in our communities. Read below on some of the parasites we commonly find in and on our pets.

External Parasites

Often, we can visualize external parasites on our dogsif we look closely enough. However parasites such as mites and even some cases of flea infections can be almost impossible to visualize. Diagnosis often requires skin scrapings to look under the skin and in some cases medication trials. There are also several options for treatment that will prevent infection of each of these parasites. In Ottawa, we are primarily concerned with ticks and fleas.

Ticks – We see several types of ticks, especially in Dunrobin, including the American Dog tick and Deer tick. In addition, there is an emergence of new ticks in Ontario which have made their way to Ottawa including the Lone Star tick. The primary concern is not so much the actual tick bite, but instead the transmission of tick-borne bacteria – Lyme, Anaplasma, and Ehrlichia. Each bacteria behaves differently and signs that your pet is infected varies but pets often present with fever, lethargy, inappetance, and lameness. Because infection is so common in our area, we screen pets annually with a blood test that determines exposure to those bacteria as well as heartworm. Treatment for tick-borne diseases is available and can work eliminate the pathogens from our pets, but prevention with anti-parasitics is more reliable and effective. If you are noticing ticks around your home and community, speak with our staff on starting prevention for your pet. If a tick has bitten your dog, the screening test will detect exposure to the pathogen 30 days after the initial bite.

Fleas – These parasites are often dropped off by infected wildlife and can quickly infect entire homes. Flea bites can cause allergic reaction in our pets leading to intense itchiness. Furthermore, fleas are the intermediate host in one type of tapeworm infection. These parasiteswill rudely bite humans too. Treating tick infestations is easily done with veterinary-approved medications, where often 1-2 treatments can treat infestations.

Mites – There are many different types of mites that can infect our dogs. Ear mites, Sarcoptic mites (causing Scabies or “Mange”), Demodex mites and so on. Some of these infections cause extreme itchiness and secondary infections. In addition, some are transmissible to humans.

Intestinal Worms

There are several intestinal worms that we worry about infecting our pets- roundworms, hookworms, whipworms and these intestinal parasites can affect growth and development in our puppies, cause decreased health in adult dogs, and can also be a dangerous zoonotic risk if passed on to humans (especially children). Most infections can be picked up through routine fecal analysis looking for worm eggs. Treatment of intestinal worms often involves multiple treatments of medication spaced several weeks apart in order to ensure all adult worms are removed from the intestines.

Roundworms – Infection occurs through ingestion of infective eggs from the environment – either from contaminated soil, from ingesting an infected rodent, or through the mother’s placenta and/or milk in newborn puppies. Once ingested, the larvae migrates throughout the dog’s intestines, liver and lungs (depending on species) before growing into an adult and laying eggs that pass in the dog’s feces. These worms can grow up to 7 inches in the intestines. This worm does pose a risk to humans! If a human ingests an infective egg, the larvae travel randomly throughout the body before dying, and in many cases, end up in the eye, causing blindness. Eggs are fairly hardy in the environment and can survive freezing temperatures. If you notice a large, slender worm in your dogs vomit or stool, chances are it is a roundworm.

Hookworms – Infective larvae found in the environment can infect its host in several ways – either directly by penetrating the animal’s skin through the feet or belly, any skin touching the ground (these little guys have teeth!), by the dog self-grooming after contact with infected soil, or by ingestion of an infected animal or insect. These worms can also be passed onto a newborn litter of puppies via an infected mother’s placenta and milk. Hookworms actually suck blood from their host, which can cause anemia in severe infections. These infective larva can also burrow into human skin if contact occurs with contaminated soil. Direct ingestion of contaminated dirt will also cause infections in humans.

Tapeworms – There are several types of tapeworms that can infect our pet. All tapeworms go through a cycle which includes an intermediate host (that is, our pet sheds the tapeworm eggs, which are ingested by either a flea, a grazing mammal, or a rodent for example, where the tapeworm develops further. The animal must then ingest the immature tapeworms from the intermediate host to finish the life cycle). Our primary experience with tapeworm is with cats that heavily hunt. They will often harbour tapeworms and become easily reinfected once hunting resumes. Luckily tapeworms are easily treated, but care must be taken to treat flea infestations and/or prevent scavenging of carrion to prevent re-infection from occurring. Tapeworms can also infect humans through the same mechanisms, but not directly from our pets.


Heartworm disease is literally due to a worm, transmitted by mosquitos, that grows into an adult in a pets heart. This results in an inflammatory response or obstruction of blood flow, and can lead to heart failure and death. Luckily we have a simple blood test that can detect heartworm disease before heart failure develops, leading to a better prognosis. And if a pet does contract heartworm disease, the treatment to get rid of the worms can be life-threatening in itself, and it can be quite expensive. Therefore, we always aim to prevent it from occurring in the first place with monthly heartworm prevention during the Summer and Fall months. It is important to remember that the heartworm parasite lingers in the area mainly due to dogs and cats who are not on prevention, and in our wild animals such as foxes and coyotes.

Luckily prevention and treatment has never been simpler. From the hundreds of different anti-parasitic medications available, but we stock only a few that have been proven to be safe, effective, and have a wide spectrum of activity, often killing several types of parasites. Routine prevention with appropriate anti-parasitic medication is often appropriate for most animals. In the end, the level of risk in contracting parasites varies and we can help develop an individualized treatment plan for your pet.