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Posted — November 27

Is Heartworm Prevention Necessary?

What exactly is Heartworm?

Heartworm disease or dirofilariasis is a serious and potentially fatal disease. Dogs are infected with heartworms by mosquitos. A mosquito will bite an infected animal and then pass the infection onto your dog should it bite him or her.


Is Heartworm Prevention Necessary?

Heartworm prevention is something many dog owners obtain from their vet on an annual basis. It can be in tablet form, or in a topical liquid that is applied to a dog’s skin. A veterinarian will perform a blood test to detect if heartworm is present, and then prescribe the preventative itself. Some of these preventatives also prevent ticks, fleas and other parasites.

What the preventatives actually do is kill any heartworm larvae in the dog’s system, with this treatment being refreshed every month or so as the preventative is administered. These preventatives are essentially treatment for heartworm, not a preventative. What they do is prevent a major infestation. In fact, if a dog has a mild heartworm infestation, a veterinarian might recommend treating it with a heartworm preventative over a course of several months.

Advanced heartworm infestations can have severe and sometimes fatal side effects in dogs, including a chronic cough, lethargy and a reduced blood and oxygen supply. When treating major infections, the dog being treated must have their activity restricted for months due to the risk of blood clots, and their heart rate must be kept low.

But there are many pet owners who do not use heartworm preventatives on their dogs.


Why would a dog owner not use a heartworm preventative?
Many dog owners feel that in certain areas of North America, particularly where it’s cooler and there is a lower incidence of mosquito bites, using a treatment on a dog is unnecessary preferring to simply have their dogs tested annually instead.

Other pet owners prefer holistic methods of heartworm prevention including natural lawn care or using methods like pet-friendly bug repellant and preventing mosquito bites which can be trickier than it sounds.

There is also some disagreement as to when to administer heartworm preventatives. Because mosquitos are most active in the late summer, many veterinarians recommend treating monthly during those specific months, while others will recommend year-round treatment. Some holistic vets may recommend only treating every three months or so, receiving fewer doses of the medication (and as they perceive it, less of the risk) while still receiving enough of the medication to kill heartworms as they develop but before they have a chance to reproduce.


What should I do if I still can’t decide?

Treating heartworm once a dog has become infected is costly and dangerous so prevention is key.  The best thing to do is speak to your vet. Ask questions and voice any concerns you may have.  When it comes to your pet’s health and wellbeing it’s always good to be well-informed.


Do you use a heartworm, flea or tick preventative on your dog? Why or why not? Let us know over on Instagram!


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