Heartworm disease can often be a silent but deadly killer. Heartworms are transmitted by mosquitos. The mosquito feeds on a dog or cat and ingests microfilariae within the blood. The microfilaria then mature inside the mosquito for 2 weeks, into an infective L3 Larva. The mosquito then bites another pet and the infective larva are deposited. The larva then migrate through the wound into the pet. Over the next 1-3 days the L3 larva mature into an L4 larva in the subcutaneous tissue. L4 larva, then migrate through tissues and mature over the next 50-70 days. Immature worms can migrate to the heart and lungs as early as 70 days post infection. Mature worms primarily live in the pulmonary artery which is located between the heart and lungs. They stay in the pulmonary artery and produce microfilaria (baby heartworms). Microfilariae can be detected in the bloodstream as early as 6 months post infection. A mosquito feeds on the pet and is then infected by the microfilariae. The cycle continues.
The Companion Animal Parasite Council has 3 main recommendations:
- Annual testing of all dogs.
- Protect all dogs from heartworm infection by using monthly preventives year round.
- Treat all infected dogs as soon after diagnosis as medically practical.
Our favorite heartworm preventives for dogs are Heargard and Sentinel Spectrum.
Our favorite heartworm preventive for cats is Revolution.
Heartworm Fun Facts:
Heartworms live approximately 5-7 years in the dog.
Heartworm disease in dogs causes signs of heart disease, whereas heartworm disease in cats causes signs of respiratory disease.
Dogs when diagnosed can have several hundred heartworms in their pulmonary artery, whereas cats typically only have 1-3 worms at the time of diagnosis.
