Heartworm Disease In Dogs and Cats
By Rachele Baker, DVM -Heartworm disease is a serious disease transmitted by mosquitoes. Heartworms (Dirofilaria immitis) invade the heart, lungs, and blood vessels of affected animals. Heartworm disease can result in severe lung disease, heart failure, and damage to other organs in the body.
Heartworm disease can affect both dogs and cats. Dogs are natural hosts for heartworms. Therefore, heartworms living inside a dog will mature into adults, mate, and produce offspring. Cats are atypical hosts for heartworms.
Mosquitoes are an integral part of the heartworm life cycle. When a mosquito bites an infected dog, fox, coyote, or wolf and takes a blood meal, it picks up baby heartworms (microfilaria) which then mature within the mosquito into larvae over a period of 10 to 14 days. When the infected mosquito bites another susceptible animal, the larvae are deposited onto the animal’s skin and enter the animal through the opening in the skin caused by the mosquito bite.
This table from the American Heartworm Society presents an extremely interesting synopsis of heartworm disease in dogs compared to cats.
The American Heartworm Society has recommended the following guidelines for the use of heartworm preventatives in dogs and cats:
“Puppies and kittens should be started on a heartworm preventive as early as possible – no later than 8 weeks of age. Only use heartworm preventive medications approved for pets and prescribed by your veterinarian.
Give heartworm preventives as directed. Make sure your pet gets the right dose for his or her weight and give the medication on schedule.
Dogs and cats over 6 months of age put on heartworm preventive for the first time should be tested for heartworm disease before the preventative is started. Dogs should be tested a second time six months later and thereafter a minimum of once a year. Early detection provides the best opportunity for treatment success.”
I created the following table to provide information about some commonly prescribed oral and topical heartworm preventatives:
If you live in an area where there are mosquitoes, then your dog or cat is at risk of contracting heartworm disease. The best way to protect your pet is to make sure that your pet receives a heartworm preventative every month.