April is American Heartworm Awareness month, a disease that afflicts between 1 million to 1.2 million dogs per year, according the the American Heartworm Society (AHS). This number is likely much higher with many cases not being reported to the AHS.
Heartworm disease is transmitted by the bite of a mosquito that is carrying a microscopic infective stage of the heartworm called microfilaria. Once injected into the dog hosts's blood stream, the larva develops eventually into a reproducing adult worm.
Thus, heartworm is prevalent wherever there are mosquitoes. Neglected dogs and wildlife reservoirs such as foxes and coyotes maintain heartworm disease endemically in most environments, including urban and suburban environments.
Thankfully, heartworm is very effectively and safely prevented with a number of different products that simply require feeding a chewable tablet to a dog once per month. Within the tab is a safe micro-dose of a macrocyclic lactone, a class of compounds derived from naturally occuing soil bacteria that kill the juvenile stages of certain types of worms, but are virtually harmless to mammals.
Treating for 12 months of out the year is the best strategy to prevent heartworm disease in dogs. Leaving aside for a moment the painful and debilitating effects of heartworm disease in dogs, the cost of treating a heartworm positive dog is more than the cost of 10 years worth of heartworm prevention medication. The cost in quality of life and less years of longevity when dogs become infected with heartworm, cannot be quantified monetarily.
The other side of the 12 & 12 strategy of prevention is to screen the canine patient once yearly for heartworm disease via a simple and inexpensive blood test as part of their yearly well visit. Although heartworm prevention medications are very effective, nothing is 100%. Yearly screening enables early detection of heartworm disease which enables the veterinarian to administer treatment early in the stages of disease to minimize damage to the heart and lungs.
Dr. Roger Welton is a practicing veterinarian and highly regarded media personality through a number of topics and platforms. In addition to being passionate about integrative veterinary medicine for which he is a nationally renowned expert, Dr. Welton was also an accomplished college lacrosse player and remains to this day very involved in the sport. He is president of Maybeck Animal Hospital , runs the successful veterinary/animal health blogs Web-DVM and Dr. Roger's Holistic Veterinary Care, and fulfills his passion for lacrosse through his lacrosse and sport blog, The Creator's Game.