Everything You Need to Know about Heartworm and Your Dog

What is Heartworm?

Heartworm is a disease caused by its namesake, the heartworm, known scientifically as
Dirofilaria immitis. It is a parasitic roundworm that thrives inside dogs. It is transmitted
through a mosquito bite. Heartworm has a much higher incidence in warm weather countries
were mosquitoes thrive.
Heartworm settles within the chest area and collectively form clumps in blood vessels around
the heart and the lungs. This causes arterial blockage and can result in a multitude of symptoms,
culminating in the eventual death of the dog if left untreated.

What are the Symptoms of Heartworm?

Heartworm is a silent, and painfully slow, killer. Sometimes the development of symptoms can
be confused with your dog aging. Some heartworm-related aging signs include premature
greying of the muzzle and the forelegs. The coat also loses its luster and the dog may become less
energetic without reason.
Persistent coughing is also another symptom. Because the parasite breeds within the chest
region of the host, the lungs and heart are affected the most.
As the worms expand in the chest, airways, veins and arteries become congested due to the
worms forming a lethal blockage as they continue to reproduce. The infestation initially results
in a soft, dry coughing and eventually becomes a persistent cough most noticeable during night
Your pet may also become increasingly inactive as the infestation progresses. Due to the
blockage present in the dog's circulatory system, the transfer of nutrients and even oxygen
becomes impaired.
Because of the difficulty getting the air and nutrients it needs, your dog begins to lose energy.
Eventually, even the most basic of actions such as standing up and eating become too difficult to
perform. At this stage of infection, you may notice rapid weight loss in your pet.
Also, obstructions caused by the worms, their eggs and the remains of their dead collectively
cause inflammation and blockage in the circulatory system, particularly within the chest area,
the lungs, the abdominal area and the liver. Fluid builds in the body, causing your dog's chest
and stomach to enlarge and protrude.

How Do You Prevent Heartworm?

While a common illness in dogs, heartworm is actually preventable. To prevent your dog from
contracting heartworms, give your pet a preventative medication once a month. Some common
Heartworm medications include Ivermectin (Heartgard), Milbemycin oxime (Interceptor),
selamectin (Revolution) and Imidacloprid-moxidectin (Advantage Multi aka Advocate Spot On).
Have a discussion with your veterinarian to see which of the heartworm medications is right for
your pet.

What Can You Do if Your Dog has Heartworm?

Ordinary worm medicines will, unfortunately, be ineffective against heartworm once your dog
has already been infected. Curing heartworm, especially if it's already in the advanced stages,
also carries significant risk.
For most treatments, the process begins with Ivermectin in order to kill undeveloped worms.
The drug, however, will not get rid of those heartworms already in the arterial canals. The
second step is to get rid of the mature worms, which can only be done through the application
of Melarsomine Dihydrochloride, a potent and high-risk drug containing arsenic.
Ultimately, trying to cure Heartworm is expensive and dangerous to your dog, so the best cure is
to ensure your pet never contracts the deadly disease.
Does your dog have fleas? Comfortis kill fleas and is indicated for the prevention and treatment of
flea infestations (Ctenocephalides felis) on dogs and cats for one month per dosage.


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