Dog Heartworms, often known as heartworm disease or dirofilariasis, are a mosquito-transmitted parasitic nematode (roundworm) known as Dirofilaria immitis. Mosquitoes consume microfilariae, which are immature heartworm larvae, when they feed on an infected dog or cat.

Heartworm disease affects dogs, cats, and ferrets, but heartworms are also found in sea lions, coyotes, foxes, wolves, and in very rare cases, people. Because foxes and coyotes inhabit close proximity to many metropolitan areas, they are regarded as significant disease vectors.


What Is The Heartworm’s Life Cycle?

Before the heartworm finishes its life cycle in the dog, it requires an intermediate host, the mosquito. The mosquito is essential to the entire lifecycle of heartworms.  Up to 30 species of mosquitoes are capable of transmitting heartworms.

The parasite’s life cycle begins when a female mosquito feeds on the blood of an infected dog, consuming microfilariae. Before reaching a mosquito’s mouthparts, microfilariae develop in its stomach for 10 to 30 days. They are infectious larvae that may complete their growth within a dog at this stage. When a mosquito bites a dog, infectious larvae enter the dog’s body.

After entering the host’s bloodstream, these larvae move to the heart and surrounding blood vessels, where they mature into adults, reproduce, and produce microfilariae within six to seven months.

What Are The Symptoms Of Dog Heartworm?

In the first stages of the illness, many dogs exhibit little or no symptoms. The longer an infection remains, the greater the likelihood that symptoms may manifest. Dogs who are active, highly afflicted with heartworms, or have other health issues often exhibit prominent clinical indications.

Heartworm disease is characterized by an unwillingness to exercise, exhaustion after moderate exertion,  mild chronic cough, weight loss, and reduced appetite. As heartworm illness advances, dogs may suffer heart failure and an enlarged abdomen owing to an accumulation of fluid. Dogs infected with a high number of heartworms are susceptible to unexpected obstructions of blood flow inside the heart, which may result in a life-threatening cardiovascular collapse. 

How Is Heartworm Disease Diagnosed?

Dog heartworm may usually be identified with one or more basic blood tests. Heartworm-positive dogs may need additional diagnostic tests to establish whether they can safely undergo heartworm disease treatment. Any or all of the following diagnostic tests are suggested before initiating therapy:

  • Bloodwork (complete blood cell count, serum biochemistry)
  • Chest radiographs (X-rays)
  • Serological test for antigens to adult heartworms (antigen test, ELISA)

How Dog Heartworms Disease Treated?

Protecting your dog from heartworm illness is simple and effective. Dogs that are already sick from illness are given numerous treatments. In order to select the most effective course of therapy, the following tests will also be conducted to evaluate the disease’s stage and severity:

  • Urinalysis
  • Antigen test
  • Radiographs, or X-Rays
  • Ultrasounds 

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