Skip to Main Content
Ask About Financing

Heartworm in Dogs: Signs, Prevention. & Treatment

There is a serious condition that dogs can develop called Heartworm disease. This disease can cause irreparable damage to your dog's organs. In this blog, our Port Jefferson vets discuss the importance of heartworm prevention and how it can be treated.

What Is heartworm disease?

When your dog is bitten by an infected mosquito, a parasitic worm called Dirofilaria immitis enters their bloodstream and causes heartworms. Heartworm is not contagious and cannot be passed from one infected dog to another; it is only spread by mosquitoes carrying the parasite. Don't think your dog is safe from heartworm; there have been reports of heartworm in all 50 states, and it is especially common between New Jersey and the Gulf of Mexico, even along the Mississippi River and its major tributaries.

If your pup has been bitten by an infected mosquito, the worms will grow into adults, mate, and produce offspring while residing in your companion's heart, lungs, and blood vessels.

Heartworm Prevention in Dogs

Our veterinarians at Jefferson Animal Hospital cannot emphasize the importance of heartworm prevention enough because it is far superior to the treatment options available. If you have not already done so, we recommend contacting your veterinarian as soon as possible to establish a prevention plan for your dog.

Usually, heartworm prevention is administered through a monthly medication that is prescribed by your vet. 

Treating Heartworm In Dogs

In situations where preventative measures don't work in preventing infection, there are treatment options available for your dog, however, all have potential side effects that can be serious and can cause health complications, however, fatalities are rare.

Since heartworm is undetectable until at least 5 months after infection, many dogs already have advanced Heartworm Disease by the time they are diagnosed and require fast and intense treatment. In rare situations, the damage to the dog's internal organs can be so severe that by the time the condition is found it's better to treat the damage and keep the pooch comfortable rather than taking the additional risks associated with attempting to kill the heartworms. Dogs in this advanced condition have a life expectancy of only a few weeks or months. 

If you see your dog displaying any signs of heartworm disease contact your vet immediately. Some of the symptoms of heartworm include fatigue, getting tired easily after only mild exercise, a persistent cough, a large belly, reduced appetite, and weight loss. There are some rare and very severe situations where dogs can get Caval Syndrome where your pup could suddenly collapse and potentially die.

Thankfully, a new medication for killing adult heartworms with fewer harmful side effects has been developed. Melarsomine is an injectable medication that kills adult heartworms and is given in a series of injections. After the first injection, your dog will typically be given a 30-day rest period before receiving two more injections 24 hours apart. Antibiotics will also be prescribed to combat any infectious bacteria that the heartworms may be carrying. 95% of dogs with heartworms can now be successfully treated with this new medication.

Your dog will also receive treatment to kill juvenile heartworms (microfilaria) either before or after their Melarsomine treatment. Your dog may need to spend the night in the hospital for observation on the day this treatment is administered.

What To Do After Your Dog Has Been Treated For Heartworms

Following the injection, you must allow your dog to rest. Heartworm treatment in dogs kills adult heartworms in a matter of days, but complications can arise while their bodies decompose. The heartworms may take several months to be reabsorbed into the patient's bloodstream. Because most post-treatment complications are caused by fragments of decomposing heartworms, your dog should not be allowed to exercise and should be kept as quiet as possible for the first month after treatment. Coughing will be noticeable for seven to eight weeks after the injection. If your dog's cough persists or becomes particularly severe, or if he exhibits shortness of breath or fever, contact your veterinarian immediately.

The Side Effects Of Heartworm Treatment In Dogs

Heartworm treatment can have serious consequences for your pet's health and can be toxic to the dog's body. Many dogs experience soreness and swelling at the injection site. The most severe side effects are associated with a large number of worms suddenly dying. If your dog pants excessively, has difficulty breathing, becomes lethargic or collapses suddenly, begins to reject food, vomits, or develops diarrhea, you must contact your veterinarian immediately.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. Please make an appointment with your vet for an accurate diagnosis of your pet's condition.

Contact our vets at Jefferson Animal Hospital immediately if they are displaying any signs of heartworm or side effects of their heartworm treatment. 

New Patients Welcome

Jefferson Animal Hospital is accepting new patients! Our experienced vets are passionate about the health of Port Jefferson companion animals. Get in touch today to book your pet's first appointment.

Contact Us

(631) 473-0415 Contact