For the past two years, veterinarians and pharmaceutical companies have teamed up in a marketing campaign to frighten pet guardians into giving year-round heartworm preventatives to both dogs and cats. The campaign has really ramped up this year. They say they're doing this to improve protection for individual pets, but we need to take a closer look to discover the truth.
When an infected mosquito bites a dog or cat, the heartworm microfilaria are deposited on the skin, where they crawl into the bite wound and enter the bloodstream. Inside the body, they get ready to "settle down and raise a family." In dogs, the heartworm natural host, the larvae migrate to the heart and eventually develop into adult worms, reproduce, fill the blood with microfilaria, and pass it on to the next mosquito. The maturation process takes 6-7 months.
"Heartworms have been diagnosed even in cats who spend 100% of their time indoors."