Heartworm disease can undoubtedly be devastating for dogs that contract it.  There are preventatives available, and the best program for your dog should be based on individual risk.   Your dog’s risk will be based on two key factors:

1. Exposure to mosquitoes

2. The environmental temperature where you live.

Mosquitoes thrive and breed in standing water.  If your dog is exposed to lakes, ponds, or other pools of water, there will likely be some mosquito exposure during the summer months.

The heartworm larvae must go through a life-stage cycle in the mosquito in order to be able to infect your dog, and this transition requires a temperature of 57 degrees or higher for 30 consecutive days. Here in Colorado, we have cool nights, so the risk of heartworm disease is much lower.   In warmer climates, the risk is much higher.

In Colorado, I recommend prevention only during the warm summer months of June, July, and August.  In my experience, finding a heartworm positive dog that lives in Colorado is extremely rare.  In other parts of the country, where mosquitoes are more prevalent and the temperatures are warmer, the risk will be much greater.  If you live in, or travel to other areas of the country, your dog should be on prevention for more of the year.

Keep your dog heartworm free by assessing risk based on the factors above.  Next:  see my post on heartworm preventatives, both traditional and holistic.