Heartworm in Dogs

Heartworm in DogsOne of the most difficult diseases to treat in dogs is heartworm.

It is important for owners to know more about heartworm, particularly how to prevent it and when to see a doctor to determine if your pet has heartworm for immediate intervention.  

Heartworm in Dogs
Since babies, Topher (left) and Rafa, dogs rescued by Save Animals of Love and Light or Save ALL, have been given heartworm prevention monthly to lessen the risk or prevent infection. 
“Heartworm is a parasitic worm that lives in the heart and pulmonary arteries of an infected animal. The worms travel through the bloodstream—harming arteries and vital organs as they go—ultimately completing their journey to the vessels of the lung and the heart chamber about six months after the initial infection. Several hundred worms can live in one dog for five to seven years, “ the American Society for the Prevention of Cruelty to Animals (ASPCA) said.

This is a serious disease and can be fatal.


Here are the symptoms:

1. Labored breathing;

2. Coughing;

3. Vomiting;

4. Weight loss, listlessness and fatigue after a moderate exercise only;

5. Some dogs have no symptoms until the late stages of infection.


The ASPCA listed the following causes:

· Heartworms are transmitted from animal to animal through mosquito bites.

· An infected animal should have two heartworms (a male and a female) for female heartworms to reproduce.

· Female heartworms produce babies called “microfilaria,” which are shed into an animal’s bloodstream. The babies cannot directly cause heartworm. It must pass through a mosquito first.  

· Microfilariae must be in the mosquito and transform into infective larvae over a two-week period inside the insect.

· When a mosquito bites a dog, the infective larvae will enter the tissues and begin a migration into the blood vessels.

· Heartworms enter the dog’s bloodstream as tiny, invisible larvae, but can reach lengths of more than 12 inches when they mature.

How to diagnose heartworm

ASPCA said heartworm is diagnosed through examination, x-ray, ultrasound, and blood test.

“All dogs should be routinely screened with a blood test for heartworm either annually in spring or before being placed on a new prescription for a heartworm preventative, “ ASPCA stressed.

Dogs Prone to Heartworm

Any dog may be infected but since mosquitoes

are the carriers, dogs in hot, humid areas are more at risk of getting infected, the ASPCA said.  

How to prevent heartworm

It is easy to prevent heartworm.

1. Give your dog an inexpensive, chewable pill or topical medication available will protect your dog. Please ask your vet about this.

2. The pills or topical are usually given monthly to dogs under six months of age without a blood test.  BUT older animals must undergo a blood test before giving the medication.

3. The American Heartworm Society strongly suggested that a dog be kept on preventive medication monthly for the whole year. “Not only does this avoid errors, but many of the products also prevent other intestinal parasites, “ the ASPCA said.


If a dog has heartworm, the infected dog should be examined completely to determine the best treatment plan and the potential risks involved.

The ASPCA enumerated the following treatment plan:

1. The most common treatment plan involves a series of injections of drugs called adulticides into the dogs’ muscle, the ASPCA said.  “This cure has a high success rate and usually requires hospitalization,” the ASPCA added.

2. All treatment plans require several weeks of exercise restriction after treatment and each involves risks to the pet. Thus, the ASPCA stressed: “Disease prevention is a much better and safer option.”  

3. After treatment, your dog should be given preventive meds to reduce being infected again.

Heartworm in Dogs
Lucas,  a 12-year-old shih tzu, is given heartworm prevention regularly. 
When to Consult Your Vet

Please bring your dog to the vet immediately if you

1. see your dog’s energy has decreased

2.  your dog looks ill

3.  your dog has one of the symptoms of heartworm.

Next week: Kennel Cough

Topics: American Society for the Prevention of Cruelty to Animals , dogs , heartworm
COMMENT DISCLAIMER: Reader comments posted on this Web site are not in any way endorsed by Manila Standard. Comments are views by readers who exercise their right to free expression and they do not necessarily represent or reflect the position or viewpoint of While reserving this publication’s right to delete comments that are deemed offensive, indecent or inconsistent with Manila Standard editorial standards, Manila Standard may not be held liable for any false information posted by readers in this comments section.
AdvertisementGMA-Working Pillars of the House