Emerging issues in heartworm disease

C anine and feline heartworm diagnostic methodologies as well as treatment and prevention strategies have changed considerably during the previous decade.We have experienced an unprecedented increase in numbers and kinds of available medications and diagnostic aids, and the capabilities of pet owners to acquire information of both a technical and lay nature. This can be both beneficial and detrimental in our efforts to establish and maintain effective strategies for controlling heartworm infections. Beneficial because pet owners have become more aware of the potential dangers of heartworm infections and because available treatment and prevention products have become more effective and convenient to use.Detrimental because much misinformation can be communicated through e-mail and Web sites dealing with heartworm.Additionally,the activities of newer avermectins and milbemycins against microfilariae and larval heartworms, and even demonstrated activity under certain circumstances against adult stages of heartworms,add additional possibilities to veterinarians’choices in developing and implementing control strategies.The same can be said for immuno-diagnostic assays now available for in clinic use.Possible discrepancies between traditional methods such as microfilariae detection and antigen or antibody test results can lead to some confusion regarding the actual infection status of certain pets.In this article,I will briefly discuss some of these issues.My purpose is to draw attention to these emerging issues so that veterinarians can better deal with problems that result from them.I also will discuss human heartworm infections.Little has been written about this uncommon, but important, issue.