April is National Heartworm Awareness Month—and in warm climates like Hawaii’s, awareness is especially important. The American Heartworm Society estimates that 26 to 50 cases were reported per clinic in Hawaii in 2016. We don’t want any dog or family to have to go through this ordeal, so here’s a quick refresher on the disease and its prevention.
- How many mosquito bites does it take for a dog to contract heartworm?
It takes just one mosquito bite for a dog to become infected – if the mosquito is infected with the heartworm larvae.
- Can heartworms be passed from one dog to another? No, dogs can’t pass on the infection directly.
When a mosquito bites an infected animal, the heartworm undergoes an incubation period. After that, if the mosquito bites another dog, the infection will be passed on.
- How big do heartworms get?
Heartworms can grow up to 12 inches, and they can live five to seven years.
- How many heartworms may be present in an infected dog?
It’s possible for a dog to have up to 250 heartworms.
- How long does it take for larvae to mature into adult heartworms?
When a dog is bitten by an infected mosquito, it takes about seven months for the larvae to mature into adult heartworms. They lodge in the heart, lungs and blood vessels and reproduce.
- What are the symptoms of a heartworm infestation?
Initially, there may be no symptoms. Most dogs will develop a mild, persistent cough and lose their stamina to exercise. They may have decreased appetite and weight loss. As the disease progresses, they may develop heart failure and other conditions.
- Can’t an infected dog just be treated?
Dogs can be treated for heartworms, especially if the disease is detected early, but diagnostic tests and treatment are expensive, and the treatment process itself is not easy for a dog.
- At what age should a dog start on a heartworm preventive?
Puppies younger than 7 months can start on heartworm prevention without a heartworm test and then be tested six months later and again six months after that. Dogs older than 7 months should be tested first, before receiving medicine, and then be tested six and 12 months later.
- How often should a dog be tested for heartworm?
After the initial, more frequent testing, dogs should be checked annually. Preventive medications are highly effective but not 100 percent certain, especially if a dog spits up a pill or a dose is missed.
- How often should a preventive be given to a healthy dog?
Oral and topical medications should be given or applied every month.
Sources: WebMD interview with Sheldon Rubin, 2007-2010 president of the American Heartworm Society, and the American Heartworm Society webpage.