Heartworm Prevention is Recommended Year-Round

If you have a pet, you may or may not have heard about the importance of giving your pet a monthly heartworm preventative. Over the next couple of months we will be discussing heartworm on our blog, including topics like heartworm facts, how it affects dogs and cats, the risk in your area, and what you can do to prevent it. We want to be sure you have all the information you need to protect your pet. If you have questions, feel free to visit our staff at a Community Clinic near you or call our HelpDesk at (800) 427-7973.

Heartworm has been found in all 50 states and most states have “hot spots” where the heartworm infection rate is very high compared with other areas in the same state. Factors affecting the level of risk of heartworm infection include the climate (temperature, humidity), the species of mosquitoes in the area, the presence of mosquito breeding areas, and the presence of animal reservoirs (infected dogs, foxes, coyotes).

Mosquito species constantly change and adapt to various climates and many vectors are expanding their viable season and range as weather patterns change. Some mosquito species successfully overwinter indoors creating a potential year-round risk to pets. Moist microclimates (irrigated fields, backyard ponds, man-made golf courses) perpetuate mosquito populations, and affect the severity and duration of the mosquito season. Heartworm infection in wildlife with large travelling ranges (eg. coyotes) adds to the spread of this parasite in domestic pets. In other words, heartworm is a threat to pets everywhere!

What exactly is heartworm?


Heartworms (Dirofilaria immitis) are fairly large worms (can grow up to 14 inches long) that, in adulthood, live in the heart and pulmonary arteries of an infected animal. Pets acquire these worms through mosquito bites as mosquitoes readily pick up larval heartworms from infected animals and carry them to new animals. Sexually reproducing adult mosquitoes can live up to 7 years in the host, while the mosquito-infective larva can circulate in the host’s bloodstream for up to 2 years. The primary hosts are domestic and wild dogs (wolves, coyotes, foxes, etc.), but it can infect cats, humans, and other mammals. Currently, a warmer than normal climate has increased the presence of mosquito breeding areas in all 50 states. Heartworm in canines results in lung disease, heart failure, other organ damage and sometimes death.


Early signs may show when a dog or cat is infected with heartworms, so detecting their presence with a test is important. All that’s required is a small sample of blood from your pet and results come back quickly. If your pet tests positive you will need to seek advice from your fulls service veterinarian on next steps. All dogs should be tested for heartworm annually. Tests can be obtained from all VIP Petcare clinics.


VIP Petcare recommends administering a heartworm preventative product to your pet every month for the duration of its life, as well as an annual test to ensure your pet is free of heartworm disease. Please note, in order to start your pet on heartworm prevention you must have proof of a negative heartworm test from the last 12 months.

What are the signs of Heartworm in dogs?

  • A soft, dry cough. The parasites make their way to the lungs and start multiplying in the lungs and surrounding veins
  • Inactivity or lethargy
  • Weight loss or anorexia
  • Rapid or difficult breathing
  • Bulging chest
  • Allergic reaction
  • Collapse
  • What are the signs of Heartworm in cats?

  • Coughing, asthma-like attacks
  • Periodic vomiting
  • Lack of appetite or weight loss
  • Occasionally an affected cat may have difficulty walking, experience fainting or seizures, or suffer from fluid accumulation in the abdomen
  • What are the risks in my state?


    For more information on heartworm disease, visit www.heartwormsociety.org or www.capcvet.org.