Is Heartworm a concern in the Winter?

While heartworm disease is transmitted by mosquitos, which generally aren't a concern in the colder months, Pets First recommends keeping your pets on this preventative all year round.

Heartworm preventatives such as Heartgard Plus work retroactively, meaning they don't actually prevent new exposure to this specific parasite - they actually take care of previous exposure, meaning even if it's 35 degrees today, Heartgard will cover your pet for the previous month when it was still warm enough for mosquitos to thrive.

Most heartworm preventatives also protect against intestinal parasites, which are a concern all year, especially if your dog goes to daycare.