The Truth About Fleas and Ticks in Winter

Many people believe that their pets are safe from parasites as soon as they’ve had a couple of hard frosts. I used to think this as well. With the polar vortex bearing down on us again this winter, our thoughts tend to turn towards stockpiling salt and snow shovels- not our pets’ preventives. After all, fleas, ticks, and mosquitoes couldn’t possibly survive the slushy, white mess we’re in for, could they? I’m afraid I have bad news on that front. These parasites seem to be tougher than many of us have given them credit for. They’ve adapted to make use of the warmth that humans provide to extend their active seasons. So as long as there is warm-blooded wildlife and people have central heating, there are still going to be fleas, ticks, and mosquitoes- even when the white stuff is still on the ground.

Fleas can survive our most frigid winters by going into a hibernation-like state in burrows created by moles or other wildlife. They can wait for months in their dormant state, waking up when they sense their next meal. If they seek shelter under houses or on wildlife, they don’t even have to go into their dormant state. On their own, they can survive temperatures in the upper 30s (F), but their preferred shelter is on indoor pets. These reasons make fleas a year-round problem.

Ticks are the most hardy on this list. They are not killed off by the winter temperatures in our area. Most species go into a hibernation-like state in the leaf litter when temperatures drop. The exception to this is the deer tick- famous for carrying Lyme disease. Deer ticks are active all year long. They will actively seek out hosts as long as the air temperature is above 32F. When temperatures rise above freezing all ticks are capable of carrying diseases that can be spread to you and your pet.

Mosquitoes become inactive when the temperature drops in the winter. Some species can survive deep freezes by seeking shelter under houses or in other sheltered areas. There’s even a species of mosquito that hangs around doorways waiting to come inside for their next meal. There they wait in a dormant state for the temperature to rise above 50F. Other species lay their eggs in freezing water to hatch on warmer days. Both of these are sometimes referred to as “snow mosquitoes” as they can at times be seen when there is still snow on the ground. Our winters are generally not consistently cold enough to offer protection from mosquitoes and the diseases they carry- such as heartworms.

All of this highlights how important year-round prevention is. We at Animal Doctors are happy to help you choose the best protection for your pet.