Community Animal Hospital

For years, seasonal-only (June through November) heartworm preventative has been recommended in our cool weather climates.  Development of heartworm larvae within the mosquito depends on the temperature outside, and it has been shown that development stops when temperatures drop below 57 F.  Recently, however, there is new evidence that some heartworm preventatives may not be 100% effective in certain situations.  Recent experimental studies on the effectiveness of heartworm preventatives have shown a rate of only 95% effectiveness when one dose of heartworm is given to dogs who have been exposed to heartworm.  However, when dogs are given a dose for at least 3 consecutive months, there was a rate of 100% effectiveness (no dogs became infected).  There is, therefore, a higher chance of effectiveness when giving year-round prevention.

At this time, reports of resistance appear to be confined to dogs in other areas of the United States, however, both the American Heartworm Society (AHS) and the Companion Animal Parasite Council (CAPC) are recommending year-round administration of heartworm preventative in all areas of the United States.

For these reasons, Community Animal Hospital is now recommending year-round heartworm prevention administration.  Being sensitive to the cost of year-round prevention, Community Animal Hospital's prices reflect the most competitive possible. 

As heartworm prevention medication is a prescription drug, we are still requiring heartworm tests for dogs.  As a preventative, we are also recommending administering year-round heartworm medication for cats.