Protecting Pets from Heartworm

By Karin Krisher

Because we’ve grown to know and love dogs as companion animals, any sort of invaders or predators to their systems, like the infamous heartworm, are real worries for us humans. Educating your customers can be a great way to ease those worries and protect dogs in one go.

Heartworm is only transmittable through contact with a carrier—the mosquito—during periods when temperatures are over 57 degrees Fahrenheit. But your customers have probably heard by this point that worrying isn’t just for summertime. (If they haven’t, it’s worth mentioning.) Without taking preventative measures, your customers’ headaches (and their dog’s unhappiness, discomfort, etc.) will be much worse later.



While we encourage you to speak to your customers about heartworm and preventative measures, getting them to your office for a simple discussion to encourage a test in the first place is always a task. Therefore, the following paragraphs are written with the regular Internet user in mind—all you non-doctor dog owners out there who are looking for more information before you schedule an appointment.

How to begin heartworm prevention

Where should you start? First, do a test. You need to be positive your dog doesn’t already have heartworm before you begin preventative measures, as the two can be a fatal mix. Go see a vet for this one, and start at six months of age.

Regarding seasonal concerns, experts say that if you live in the New England area, beginning in May is an intelligent decision. That’s when temperatures increase enough for mosquitos to begin their buzzing. However, to ease your mind and your dog’s chances of developing full-blown heartworm, doing a once a month treatment year round is a good idea.

It works like this (and your vet can explain this further): preventative drugs don’t actually prevent the bug from biting, or even the larvae from being transferred. But they disrupt the growth process so that the microfilaria that normally develop into adult worms don’t ever reach that stage.

Any prevention failures (missed doses) are generally the result of some human error—or some dog vomit. These unforeseen events are the reason your dog should be regularly tested at an interval determined by your veterinarian (usually every year).

If your dog does contract heartworm, there are treatment options, but treatment is lessheartworm than ideal. (Prevention is ideal.) The heartworm should be staged before beginning treatment because, while stage 1 and 2 have a good prognosis, treatment in stage 4 is contraindicated, meaning likely fatal due to abnormal heart rhythms.


During heartworm treatment (not prevention), your dog should be on cage rest and kept relaxed for six weeks prior to dosing. This act alone is difficult—you have to be on constant watch so that his or her heart stays calm. Don’t let it get that far. Ask your veterinarian for prevention advice (if you haven’t already) and get to the heart of the problem today. If your dog’s ever had heartworm and you have any advice, leave a comment!

Vets—mention prevention to each client in your office, either through a brochure from a trustworthy source or a personal conversation. And let us know if you’ve had a difficult experience with heartworm prevention or treatment—or a good one!