CANINE HEARTWORM PREVENTION

This concerning condition often creates confusion on the most appropriate method of control.  Canine heartworm, Dirofilaria immitis, is a parasite that requires both the mosquito and dog to complete its lifecycle.  Below is a simple illustration of the typical lifecycle of the heartworm.

Our methods of prevention include testing and preventative medication that will kill the larva before it reaches the heart and completes its life cycle.  Testing is important to find those pets that have a heartworm infestation and hopefully begin treatment before symptoms occur.  Fortunately, most of our patients are negative and we can begin the preventative medication.  We typically prescribe one of the monthly medications and recommend treatment June through November.  Even though you may see mosquitos before and after the treatment period they are not infective at that point as the heartworm larva require a period of warm weather before they can live out of the mosquito. 

Testing is the other aspect of prevention that causes some confusion.  Here at Valley Veterinary Hospital, PC we try to follow the recommendations of the American Heartworm Society.   Previously the recommendations in low endemic areas like Colorado were to test and prescribe preventative medication, and if compliance is good to retest every other year.  Now it is recommended to test yearly.  This recommendation is based on the increasing incidence of disease found in low endemic areas.  Remember, that although the preventative medications are ususally quite effective, they are not 100%, don't let your dog be the statistic.

We realize that this is confusing.  Please click on the American Heartworm Society banner for more detailed information and please feel free to contact us with any questions.