The first official day of summer was just a few days ago but mosquito season started weeks ago. Mosquitoes are a necessary part of the cycle that leads to heartworm disease in our pets.

The first official day of summer was just a few days ago but mosquito season started weeks ago. Mosquitoes are a necessary part of the cycle that leads to heartworm disease in our pets.

Unfortunately, the potential for heartworm infection has been increasing, thanks to mosquito-friendly environmental changes.
Wallace Graham, DVM, American Heartworm Society, president says "In spite of all we know about heartworm, and our ability to diagnose and prevent it, we have not been successful in substantially decreasing incidence of heartworm disease."

There have been many cases of heartworm positive dogs in the Leavenworth area this year. These animals became infected last year or earlier. Their disease could have been avoided by simple preventive measures.

Canine heartworm infection is present in all 50 states. It is easily preventable but difficult and costly to cure. If untreated, heartworm can cause the death of the infected canine yet statistics from the Heartworm Society say that only 55 percent of American dogs are on preventive.

The cost of treatment can be from $300 to $1,000 depending on many variables. Treatment is prolonged, painful and dangerous for the pet and requires that the dog's activities be severely restricted. The yearly cost of prevention is much less than cigarettes or soft drinks for most people.

The mosquito/canine relationship is confusing but understanding it helps to sort out the myths and facts about the disease. The following is an over-simplified explanation. We will start with an infected dog. A mosquito bites him. In the process, the mosquito takes in a blood meal that contains baby heartworms (microfilaria) that are circulating in the dog's blood. Adult heartworms are already in the heart and lungs of the infected dog.

It takes 10-14 days for the larvae to mature inside the mosquito. When the mosquito next bites a dog (or cat or other mammals) it deposits infected larvae in the animal's skin. Over a period of seven to nine months, the larvae mature into worms, migrate and take up residence in the pulmonary blood vessels and heart chambers. At this point, the host dog has microfilaria circulating in their blood, mosquitoes that bite and ingest them become infected...and the cycle starts all over again.
Other dogs living with an infected one cannot "get" heartworm disease from them. The mosquito is the only transmitter and they are not going to hang around for 10-14 days. It takes the bite of just one carrier mosquito to give your dog heartworm disease. Infected pets must be treated or they will die.

Studies at Auburn University have determined that the effectiveness rate of most of the current preventives is around 95 percent in spite of an advertised 100 percent success in preventing heartworm infection. Even if drugs are not 100 percent effective, the disease will be less advanced and more easily treated. It is good to know that most manufacturers will pay for treatment unless the lack of success is due to owner's failure to give the preventive regularly and year round.
In addition to year-round administration of a preventive chosen in consultation with your veterinarian. You can reduce exposure to mosquitoes by keeping pets indoors most of the time and especially during peak mosquito times: dawn, dusk and night. Screening doors and windows and keeping outside lights off also is suggested. Mosquito-breeding sites should be eliminated. Standing water provides a nursery for mosquito larvae. Wheelbarrows, plant containers and tires should be stored upside down. Change birdbaths and wading pools weekly.

Here is a final thought: "invest in what you value." Your pets are treasures and you are responsible for them. Their health and longevity are important. You want to be able to experience the joys of pet ownership for as long as possible. The relatively small cost of regular, year-round prevention of heartworm infection is nothing compared to the expense of treating the disease, not to mention the suffering of the pet.

Anne Divine is a long time member of LAWS and has volunteered at Animal Control for 18 years. She can be reached at: