What is Heartworm Disease?
Heartworm disease is a serious and life threatening infection carried by mosquitoes. While it most often affects dogs, Heartworm still poses a very significant risk for cats. Regardless of a pet’s status as an “indoor” or “outdoor” pet, all pets are at risk of contracting this serious infection since mosquitoes can enter any home. Fortunately, this disease can be easily prevented by the use of monthly Heartworm preventative medication.
The life cycle of the Heartworm is somewhat complex: The dog Heartworm is initially transmitted when a pet is bitten by an infected mosquito. The larva, or immature worm, lives in the mosquito’s salivary glands, enters the bite wound, and then remains in the skin until it matures approximately three days later. The larva then travels to the tissues under the skin to the muscles of the abdomen and chest, where it stays for the next 2 to 3 months. The larva becomes an adult 50-70 days after the initial infection. After 70 days the worms enter the pulmonary arteries and heart, where they stay and continue to grow and mature. Fertilized female worms begin to appear 120 days after the initial infection and will contain fully developed baby worms approximately 2 months later. These baby worms cannot be detected in the blood stream of the pet for several weeks, so the time between the initial infection from a mosquito to the detectable appearance of worms in the pet’s blood is between six and nine months!
Female Heartworms can continue to produce these baby worms for the next 5 years and the babies are able to survive in the blood for up to 2 ½ years. A mosquito that bites and sucks blood from an infected pet becomes infected itself with these tiny worms, where they will mature in the mosquito until they are ready to infect another host and repeat the cycle.
These worms grow and entwine themselves throughout the vessels, heart chambers, and heart valves of the infected dog. Consequently, this leads to inflammation and scar tissue formation of the heart, high blood pressure in the arteries of the lung, heart failure, and death. Heartworm disease for cats is equally dangerous, though their symptoms differ in terms of mimicking asthma or allergic bronchitis.
Treatment for Heartworms can be very serious, and itself can be life-threatening for your pet.The disease is often very advanced by the time a pet would start to show symptoms, which is why regular testing and monthly Heartworm prevention is by far the safest and most effective approach to safeguarding your pet from this devastating illness. Because of the long and complex life cycles of Heartworms, a monthly Heartworm preventative is necessary year round – even in the winter and not just during the warmer months. Talk to your veterinarian to learn more about Heartworm and what you can do to safeguard your pet.