Over 100,000 dogs in the U.S. are diagnosed with heartworm disease each year. The disease is common, as it is spread by mosquitoes and can be difficult to diagnose.    

Heartworms are parasites that infect the host’s body and clog the lungs and arteries. Heartworm disease is a serious health danger – it can spread to other parts of the body and to other pets, and if left untreated, can result in serious organ damage, heart failure, or even death.    

The good news is, heartworm disease is highly preventable with a monthly medication given to your pet on a consistent, year-round schedule.     

Prevention is always the best medicine, as heartworm disease is not only a health risk for your pet, but treatment can be unpleasant and costly. It’s important to understand your pet’s risk factors and how you can protect your fur-baby from this disease. For more information on keeping your pet safe this summer, check out our Heat Safety Tips for Dogs,  Heat Safety for Cats and How to Beat the Heat with Your Dog.   

Is My Pet at Risk?

While heartworm disease becomes more common in the spring and summer months, it is prevalent year-round.     

Truly, all dogs and cats are at risk for heartworm, but some have a much higher infection risk, such as stray and neglected dogs. A recent study of dogs and cats in Florida animal shelters showed the prevalence of adult heartworm infection was 4% in cats and 28% in dogs.    

Wild animals such as foxes and coyotes also carry the disease, so a stray cat or dog may pick the parasite up from wildlife. Keep your pets supervised and avoid buggy areas where mosquitoes may reside. If you travel with your fur-baby, consider asking your veterinarian about the risk of infection at the location you are planning to visit.    

Heartworm in Dogs 

Dogs can get heartworms that mate and produce offspring inside the host’s (dog’s) body. There can be several hundreds of heartworms inside of one dog. Early on, there may be little to no symptoms of heartworm disease—it can go undetected for more than half of the heartworms’ life cycle. The longer the disease persists, the more symptoms will show.     

Common Symptoms of Heartworm Disease in Dogs:

  • Mild cough
  • Fatigue
  • Decreased appetite
  • Swollen belly (due to excess fluid)
  • Weight loss
  • Reluctant to exercise

In serious cases, heartworm disease can lead to Caval syndrome, which causes blockages of blood flow and cardiovascular collapse. Caval syndrome is serious in dogs and has a sudden onset noted by pale gums, heavy breathing, and dark bloody urine.     

Heartworm Treatment in Dogs

According to the American Heartworm society, there is only one drug, called melarsomine, approved by the FDA to treat heartworm in dogs. Melarsomine is an injectable, administered in a series by a veterinarian, which kills the heartworms and adjacent vessels. When given in a three-dose protocol, the drug has been demonstrated to kill 98% of worms in affected dogs.    

In severe cases, heartworm may require antibiotics, pain relief medications, dietary changes and more to improve function of the heart. If your dog tests positive for heartworm, follow your veterinarian’s specific recommendations for treatment. Each treatment option serves a specific purpose.    

Preventing Heartworm in Dogs

It’s always recommended that dogs take a monthly preventative to avoid heartworms. While no drug can be 100% effective, heartworm preventatives are shown to be extremely effective in protecting pets, as long as these preventatives are given on a consistent monthly schedule throughout the year.     

We recommend using a calendar, either print or digital, or setting reminders for yourself to help you stick to an exact schedule for administering your pet’s preventative on the same date each month. Some brands, such as Heartguard, have text reminders that you can sign up for on their website. Many medications have dosage reminders on their packaging, as well.     

The FDA and veterinary experts still recommend yearly heartworm testing, to be safe, as even one missed dose of preventative may leave your pet vulnerable to parasites.    

Heartworm in Cats

Cats are an atypical host for heartworms. It is hard to diagnose heartworm disease in cats, as only 1-3 worms are present at a time. These worms do not survive for long, but can cause further damage and complications any time they’re in a cat’s system. Heartworm-associated respiratory disease is a common ailment that cats suffer from even after having heartworms removed. Symptoms can range from subtle to dramatic.    

Common Symptoms of Heartworm in Cats:

  • Coughing
  • Asthma attacks
  • Vomiting
  • Lack of appetite
  • Weight loss
  • Difficulty walking
  • Fainting
  • Seizures
  • Fluid in abdomen

Preventing Heartworm in Cats 

Unfortunately, there is no approved medication for heartworm treatment in cats. Only preventatives are available for cats at the moment. Preventatives kill larvae so the heartworms do not develop or survive in the cat’s body.    

If your cat has an existing respiratory disease, your veterinarian may recommend chest x-rays every six months to be sure to catch any irregularities as early as possible. Follow your veterinarian’s specific recommendations in regards to heartworm prevention and treatment.     

Need Your Next Round of Heartworm Preventative?

We got you! You can obtain your heartworm preventative for your pup or kitty through JM Pet Vet Clinic, our full-service animal hospital. Call us at 508-588-5661 to schedule an appointment or to order your next round of heartworm preventatives.