Heartworm disease is a treatable health problem but can be very serious, even lethal if left untreated. Dirofilaria immitis is a worm transmitted among animals through a vector – a mosquito and can be found in the circulation of dogs and cats.
The short answer is no. Dogs with heartworms shouldn’t exercise. The restriction of exercise is one of the most important things an owner can do after the beginning of the treatment.
After the initial treatment, the main point of “home care” is to create a state with minimal to no symptoms after the first therapeutic dose. This is the part of the treatment where the worms die gradually, and the body should not be physically active and can be extremely dangerous.
If you wanna learn more about exercising in dogs affected by this parasitic disease, keep reading. Let’s dig deeper into the symptoms, diagnosis, treatment, and the amount of physical activity a dog with heartworm disease should have.
What Is the Heartworm Disease?
Heartworm disease is an illness that results in severe lung or heart failure, other organ damage, and even death in animals. It’s caused by the parasitic worm called Dirofilaria immitis. These worms are spread with the bite of a mosquito.
Domestic dogs are the definite hosts, meaning the worms can multiplicate, produce small new worms, and mature into adults while living inside the dog.
The intermediate host is the mosquito, meaning that they live inside a mosquito for a short period, enough to become infective.
The worms are named “heartworms”. This name has been given because the grown-up worms live in the lungs, heart, and connected blood vessels of the infected animal.
Symptoms of a Heartworm Disease
Heartworm disease is classified into four stages. As the disease worsens, your dog may show more obvious symptoms, which are counted as a higher stage of the disease.
- Class 1
No symptoms or mild symptoms. The dog manifests only occasional coughs.
- Class 2
Symptoms include a mild to moderate cough and tiredness after physical activity.
- Class 3
Symptoms include a sickly look, a chronic cough, and exhaustion after light activity. Breathing difficulties and signs of heart problems are the most common.
Chest x-rays for classes 2 and 3 of the heartworm disease typically show pathological changes.
- Class 4
Also known as caval syndrome – one of the main reasons for limited physical activity. The worm burden is so heavy that blood flowing back to the heart is mechanically blocked by a large mass of worms. This caval syndrome can lead to death, and immediate surgical removal is needed.
Diagnosing Techniques
The veterinarian specialist uses blood samples to test a dog for heartworms. An antigen test can detect specific heartworm proteins, known as antigens, released in a dog’s bloodstream by adult worms.
These antigen tests, in most cases, can detect infections with one or even more adult female worms. About 5 months after an infected mosquito bites the pet, veterinarians can detect the antigens in the bloodstream.
Other tests can detect microfilariae in your pet’s bloodstream. Microfilariae in the blood tell the vet that the dog is infected with adult heartworms; since only the adult versions can mate and produce the microfilariae.
Then, about 6 months after the bite is the earliest time that the microfilariae can be detected in a dog’s blood.
Physical Activities During Treatment
The treatment of heartworm disease, with minor variations, takes 2 to 5 months to complete. It is treated using a medication, and the worms must die gradually, rather than all at once – this can cause massive strokes.
During this period, you should restrict your puppy’s exercise activity to the minimum. This includes short leash walks only for bodily functions (urinating, defecating).
The dog will need to get an antibiotic, doxycycline, which can weaken the heartworms and make the adulticide injections most effective. Your dog should receive this antibiotic until the veterinarian tells you to stop.
The frequency of the therapy is once or twice a day for 1-2 months until the adulticide injection treatment. Some animals may develop indigestion from the doxycyclin. So make sure to contact your veterinarian to find an alternative when observing the loss of appetite or vomiting.
Exercise Restriction
Exercise restriction should start immediately on the day of the first adulticide injection. The injections are usually given as 2 sets: 1 injection at the beginning; then 4 weeks after, 2 more injections – 24 hours apart.
The restriction of physical activity lasts a total of 8 consecutive weeks for most dogs. Playful and energetic dogs may find this difficult, but the alternative is worse and can be deadly.
Dogs allowed to play or run during the first treatment can develop life-threatening problems such as massive strokes. The therapy makes worms fragile, which is why the body can break them down over the next 8 weeks.
Allowing physical activity at any time during these 8 weeks might cause the weakened heartworms to shatter, causing a clot of worm fragments that stops blood flow to the lungs, brain, or other organs (“shaking the tree” phenomenon).
This causes a stroke or sudden death. Conversely, exercise restriction means the body slowly breaks down the worms until they are gone, and it should cause no symptoms.
If your dog is acting weird, develops a cough, or has dyspnea (difficulty breathing), you should call your veterinarian immediately. These symptoms are the first signs of the reaction to worms that are being destructed, and it requires an immediate visit.
Each case is different; some dogs will receive cortisone tablets “per os” (prednisone), as directed by the vet. Others might not need this treatment or receive it only on an as-needed basis if respiratory symptoms occur.
The second and third injected doses will be given 24 hours apart, 1 month after the primary injection. This means that the dog will need to spend one night in the hospital for further observation.
When discharged, the dog should remain as quiet and inactive as possible for the following 4 weeks. Afterward, physical activity may be slowly increased.
To Sum Up
Physical activities during the treatment should be limited to daily walks only for bodily needs such as peeing, as they can cause deathly consequences, such as stroke.
Dogs with heartworm disease should not exercise immediately after the diagnosis and the beginning of treatment. However, after starting the proper treatment, physical activity should be included step-by-step. Our suggestion is always to follow instructions from professionals.