Heartworm Disease: Do We Need To Worry for our Pets?

By Jaimie Ronchetto, DVM >>>

If you have a dog, you most likely have heard of heartworm disease. If you have always had a dog living in Southern California, you may have been told in the past that we don’t have the disease here. However, in more recent years we are starting to see outbreaks of heartworm disease in Los Angeles County. We certainly see it in the local coyote populations, and most recently, Cinema Veterinary Centre has diagnosed a positive heartworm case in a client’s dog. Many dogs diagnosed in L.A. County may have a recent travel history to other places where heartworm disease is more common; however, in any case, monthly heartworm prevention is important.

Heartworms are parasites that live in the arteries of your pet’s lungs and, in severe cases, in the right side of their heart chambers, according to the American Heartworm Society. These parasites are a species of roundworms that need an insect species to spread it from animal to animal. The disease is spread by mosquitoes that become infected with microfilariae while taking a blood meal from an infected dog. Within the mosquito, the microfilariae mature into the infective larval stage. When the mosquito then bites another dog, cat, or susceptible animal, the larvae are deposited on the skin and actively migrate into the new host. For about 2 months the larvae migrate through the connective tissue, under the skin, then pass into the animal’s venous blood stream and are quickly transported to the arteries of the lung. It takes a total of approximately six months for the infective larvae to mature into adult worms that begin producing offspring, microfilariae. Adult heartworms can live for five to seven years in the dog.

Adult worms living in the pulmonary arteries and the heart can cause extensive damage to these organs as well as cause dysfunction of the liver and the kidneys. Infected dogs may exhibit clinical signs associated with lung and heart dysfunction including a cough, exercise intolerance and difficulty breathing. However, very acute or mild infections may not show any signs at all!

While treatment is available and usually successful for dogs that are infected, prevention is much safer and, by far, more economical. We recommend for all of our canine patients to be on a monthly heartworm preventative, in either a chewable or topical form. We offer a quick, 10-minute blood test that checks your pet for the presence of the disease, and if negative, your pet can be placed on the monthly preventative. Even with prevention, it is recommended that pets be tested for heartworm disease on an annual basis. Additional information can be found online at the American Heartworm Society.

Dr. Jaimie Ronchetto is DVM of Cinema Veterinary Centre