How Heartworm Prevention Works

To keep your pet healthy and free of disease, it’s important to provide regular vaccinations, wellness exams, and heartworm prevention. Heartworm disease has been found in all states in the US, and mosquitoes are active throughout the year, so it’s crucial to maintain year-round heartworm prevention for your pet.

The heartworm life cycle

Heartworms prefer canine hosts, cats, and ferrets. When a mosquito bites an infected animal, they ingest microfilariae, or heartworm larvae (L1), from the blood vessels. The mosquito’s gastric juices stimulate the larvae to molt to the L2 stage, and they then migrate to the mosquito’s salivary glands and molt to infective L3 larvae. When the mosquito feeds, the L3 larvae swim under the pet’s subcutaneous tissue. Over time, the larvae molt through two stages, traveling toward the pet’s heart until they finally arrive in the main pulmonary artery, where they reach adulthood and reproduce

How heartworm prevention works

Only two of the multiple larval stages of a mosquito inside a pet are vulnerable to heartworm prevention. Once the larvae reach the juvenile or adult stages, heartworm preventives cannot kill them anymore, and they require treatment with an expensive and harsh arsenic-containing drug.

It’s important to give your pet a monthly heartworm preventive, either in the form of an oral chewable or a topical liquid. This will kill off the heartworm larvae before they become stronger. If left untreated, the immature larvae can mature into adults in as little as 51 days. Regular monthly prevention is necessary to break the life cycle and protect your pet. Injections can be given to your pet every 6 or 12 months with a slow-release mechanism that kills heartworm larvae before they molt. It’s important to note that heartworm prevention does not stop mosquitoes from biting your pet or transmitting heartworm larvae, but it does prevent life-threatening heartworm disease.

During National Heartworm Awareness Month, please contact our team to discuss the heartworm preventive options available for your pet to keep them safe from the disease.