My techs hear this question all the time. “Do you really need heartworm prevention in the winter time?” Most people ask the techs because they know the answer from me is going to be: YES.
Yes, is the short answer. The long answer is this. Due to the fact that we now have multiple species of mosquitoes that stay alive as long as it is 35 degrees out and we have ones who live their entire life in a house (so it doesn’t matter how cold it is outside, they are inside). Heartworm transmission can occur during the winter months.
The Heartworm society states “Don’t assume that cooler weather eliminates the threat of diseases like heartworm, which are spread by infected mosquitoes. Mosquitoes have been known to
survive well into the winter months, thanks to indoor havens and protected microclimates
existing within larger, cooler climate zones.”
Also, the way the medication works is that it kills the parasites your pet picked up the month before. For example, say you don’t give it Dec. 1st. that means your pet could have picked up heartworms (when it was warm ) from Nov. 3rd to Nov. 30th and will continue to grow until next spring. Hurting the heart or lungs all winter long.
The other reason that we recommend it year round is because people forget. Once you get out of the habit of giving heartworm prevention studies have shown most people will forget for up to 3 months past spring. That is right!!! We are human and we forget. However, those darn mosquitoes don’t and they need to eat daily. Therefore they are transferring heartworms daily. EEK!!!. That is scary.
Also, 3 months of prevention is less than $40 for most dogs. That is a lot cheaper than $1500 for heartworm treatment. Veterinarians would make a lot of money if we would only stop telling everyone to give their heartworm prevention year round. But we don’t do this. Why??!?!? Because we actually care, have done the math and the research to back it up. So instead of making money, we recommend you do the cheaper, healthier thing by keeping your dog, cat and ferret on heartworm prevention. Mosquitoes are the number one killer of people worldwide don’t let our pets try to earn that the same statistic.
In conclusion either do an injection of heartworm prevention that gives 6 months of continuous protection or gives 1 once monthly chew. Either way be your dog’s hero and protect them from heartworms.