Parasites are common in puppies and kittens and can carry deadly diseases which can be transmitted to humans. It is important that you speak to your veterinarian about a parasite prevention protocol for your puppy now and going forward.


Heartworm is a parasite that is spread through mosquitoes. A mosquito can transfer larval stages of the worm through a bite. These larval stages can grow into long adult worms which live in a pet’s heart and lungs. It is prevalent in Ontario in untreated pets and so we recommend prevention May-November each year. Before starting preventions, we do a blood test to ensure that the parasite is not already present. In Ontario, we do not need to test pets born after October as it would be impossible for the worms to be transmitted in the winter months. However, they will be tested in subsequent years.

There are multiple types of preventions, including both topical and oral preparations. Some of them prevent other parasites as well such as fleas, intestinal parasites and ticks, which can carry diseases of their own. We will choose the proper medication based on your and your pet’s lifestyle.


Fleas are tiny parasites that live in the environment and feed off of mammals. Fleas can cause rashes, itching and severe infestations can result in anemia. Please ask us about products that can prevent fleas. Vacuuming is also recommended to remove fleas from the environment.

Intestinal Parasites

There are a variety of intestinal parasites that can live inside of our pets. Stool samples are used to determine if any parasites are present but since these tests are not 100% effective it is a good idea to have pets on a parasite prevention program. No one product will take care of all parasites and some can be transmitted to humans so routine testing is still important.


Ticks are on the rise in Ontario and some of these ticks spread Lyme disease which is a serious condition affecting joints and organs. It is now recommended that we use tick prevention and test for Lyme disease annually. Although pets can not transmit Lyme disease to humans, they can act as sentinels. That is, if your pet tests positive, we know that it is in the environment and that humans are at risk.