What to know about heartworm disease.

Heartworm disease is a serious disease that affects both cats and dogs. It is caused by foot-long worms that settle into the heart, blood vessels, and lungs of an affected pet. These types of worms can cause heart failure and lung disease and can be potentially deadly if not caught in time. Pets that survive heartworm disease often have a lower quality of life because of the damage to their organs. As April is Heartworm Awareness Month, it is important to educate yourself on what heartworm disease is and why heartworm prevention is vital to your pet’s wellbeing.

What is heartworm?

Heartworm is a type of roundworm known as dirofilariasis (or heartworm disease). The parasite that causes the disease is known as Dirofilaria immitis. It takes 6 – 7 months for larvae to mature to adulthood where it begins the reproduction cycle. A single adult heartworm can reach up to 12 inches​ in length and live up to seven years.

How do pets get heartworms?

Mosquitoes are the most common carrier of heartworm. A female mosquito picks up larvae in the bloodstream of an infected animal, then transmits the larvae into the next animal it bites. Dogs are a perfect host for heartworms which is why they are most affected by the parasite, but cats can also become hosts.

Heartworm larvae take about 6 months to develop into adult worms that settle into the organs of the animal. Once the worms take hold, the adults can live and produce larvae for 5-7 years in dogs and 2-3 years in cats.

Signs of heartworm in dogs

During the initial stages of the infection, signs of heartworm are almost impossible to detect in dogs. Your dog will act normal until the larvae have matured a few months after infection, however, they are causing damage to your pet’s health even before symptoms occur. Signs of infection include:

• Coughing
• Easily fatigued
• Lethargic
• Lack of interest in play or exercise
• Decreased appetite
• Weight loss

As the infection advances, your dog may develop heart failure and have a swollen belly from the excess fluid that the heart cannot pump out. A dog that has a large number of heartworms in its organs can exhibit Caval Syndrome which is caused by the heartworms suddenly blocking blood flow.

Signs of heartworm in cats

Cats are much less likely to be afflicted by heartworms than dogs, but it’s still a possibility. When a cat gets infected by heartworm, its organs are damaged just like in dogs. The condition, heartworm associated respiratory disease (HARD) can cause symptoms that include:

• Asthma-like attacks
• Loss of appetite
• Vomiting
• Seizures
• Difficulty walking
• Fluid accumulation

Heartworm prevention is important for cats because treatment options are limited and come with a high rate of complications. Cats can live with heartworms, but they can also collapse or die when signs are first noticed.

How is heartworm tested?

Dogs can be tested starting at 7 months old and tested again 6 months after their initial visit, especially in regions with a high prevalence of heartworm disease. Tests should be done every 12 months after the first two visits. Adult dogs who were never tested or treated for heartworm should be tested prior to starting a heartworm preventative. Afterward, the dogs should be tested six months after, then every 12 months.

Cats require a blood draw to look for antigens and antibodies in response to heartworm infection. Because cats have no approved treatment for infection, they should be put on a preventative dose as soon as possible.

Pet owners want to give their pets an excellent quality of life. Engaging in heartworm prevention is one of the best ways to help pets stay healthy. Call Blue Sky Veterinary Clinic today at  (541) 383-3833 to talk to our team about heartworm testing, prevention, and treatment for your pets.

(541) 383-3833 Blue Sky Veterinary Clinic Bend

Learn more about heartworm prevention from the American Heartworm Society video here.