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Heartworm Disease

Uncovering the Damage

You’re used to tracking heartworm disease from external signs—coughing, abnormal lung sounds, lethargy and more. But seeing the internal damage is even more sobering.


This necropsy of a heartworm-positive dog shows the devastating, far-reaching effects of heartworm disease on canine heart and lungs.

The heart and lungs have been removed from a heartworm-positive dog; this image shows dissection to the level of the pulmonary valve.
Here, we see dissection distally along the pulmonary artery (white areas) ...
... and more distal dissection along the pulmonary artery reveals a heartworm.
A closer look at the pulmonary vessels in the lung shows heartworm damage (red) compared with a normal, undamaged area (white).
Here, we can take a closer look at the heartworm and vascular damage.


Heartworm disease threatens dogs in all populated areas.

U.S. Population Density

US Populaton Map

Melarsomine Dihydrochloride Use by ZIP Code6

US Melarsomine Map

About These Maps

The population map and usage map (melarsomine dihydrochloride) are very similar.

  • Together, they indicate that heartworm disease can be found in every populous area.

The areas with few or no red dots tend to be sparsely populated and have fewer veterinary practices.

  • Far less testing is being conducted in those areas.
  • That lack of testing or reporting doesn’t indicate an absence of heartworm infection.

Advances in Heartworm Disease Preventatives

ProHeart® 6 (moxidectin) is the culmination of nearly 25 years’ progress in heartworm disease prevention.7

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Diethylcarbamazine (DEC), the first heartworm disease preventative, makes its debut—as a daily oral tablet.
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Monthly oral preventatives are introduced via veterinary clinics, paving the way for longer-lasting doses.
Proheart 6 Dog
Monthly topical preventatives enter the market, expanding dog owners’ options.
Proheart 6 Dog Injection
ProHeart 6 is introduced as a simple-to-administer, six-month injection. It sets still-unsurpassed records for compliance and convenience.
Proheart 6 Bottle and Injection
ProHeart 6 is still the only injectable heartworm product that ensures compliance.
IMPORTANT SAFETY INFORMATION: PROHEART 6 should be used in healthy dogs. Do not administer to sick, debilitated, underweight dogs or dogs that have a history of weight loss. Prior to administration, PROHEART 6 certified veterinarians should continue to assess patient health through a medical history, physical examination and if deemed appropriate, diagnostic testing. Continue to use caution when administering PROHEART 6 concurrently with vaccinations. Adverse events, including anaphylaxis, have been reported following the concomitant use of PROHEART 6 and vaccines. In some cases, anaphylactic reactions have resulted in death. Use with caution in dogs with pre-existing or uncontrolled allergic disease (food allergy, atopy or flea allergy dermatitis). Dogs receiving PROHEART 6 should be tested for existing heartworms as per the product label. In people, avoid PROHEART 6 contact with eyes. If contact with the eyes occurs, rinse thoroughly with water for 15 minutes and seek medical attention immediately. PROHEART 6 is available only to veterinarians through a restricted distribution program. Only certified veterinarians and staff can administer it. To obtain additional information including a copy of the product labeling, click here or call 1-888-ZOETIS1 (963-8471).
  1. VetInsite™ Analytics 2015. Zoetis Data on file.
  2. Hampshire VA. Evaluation of efficacy of heartworm preventive products at the FDA. Vet Parasitol. 2005 Oct 24;133(2-3):191-195

U.S. Population Map

US Population Map Fancy

Melarsomine Dihydrochloride Use by ZIP Code

US Melarsomine Map Fancy



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