- Embrace Pet Insurance reports heartworm diagnosis claims increased 201% between 2020 and 2025.
- Claims data showed heartworm cases occurring throughout the year, reinforcing recommendations for year-round prevention.
- Increases were observed in several states not traditionally considered heartworm hotspots, including Illinois, Michigan, Rhode Island, and Maine.
- Nearly 79% of heartworm claims involved pets 4 years of age or younger.
- The findings align with broader industry reports indicating heartworm continues to expand beyond historically high-risk regions.
Heartworm disease may be affecting more pets in more locations than many owners realize, according to new claims data released by Embrace Pet Insurance.
The company reported a 201% increase in heartworm diagnosis claims between 2020 and 2025, reflecting a trend that mirrors findings from veterinary organizations documenting the continued spread of the mosquito-borne disease across the United States.
Claims data suggests expanding geographic risk
While heartworm has historically been associated with the southern United States, Embrace’s analysis found diagnosis claims occurring throughout the country and during every season of the year.
The insurer identified notable increases in heartworm claims in several states outside traditional high-incidence areas, including Illinois, Michigan, Rhode Island, and Maine.
The findings are consistent with reports from the American Veterinary Medical Association and the American Heartworm Society, both of which have documented increasing heartworm prevalence and continued expansion into regions once considered lower-risk areas. Animal Health News previously covered the American Heartworm Society’s latest heartworm incidence map, which showed Texas continuing to report the highest number of heartworm cases in the United States.
Year-round prevention remains essential
Embrace’s claims analysis found heartworm diagnoses occurring year-round, supporting veterinary recommendations that preventive medication should be administered consistently rather than only during peak mosquito season.
Dr. Julie Hunt, veterinary consultant for Embrace Pet Insurance, said the greatest risk factor for heartworm disease is inconsistent prevention, noting that mosquitoes capable of transmitting the parasite are not confined to one region or season.
Heartworm disease is transmitted through the bite of infected mosquitoes and can affect both dogs and cats. Once established, the parasites can damage the heart, lungs, and blood vessels, potentially leading to heart failure, lung disease, organ damage, or death if left untreated.
Younger pets represented the majority of claims
According to the insurer, 79% of heartworm diagnosis claims involved pets 4 years of age or younger, with young adult dogs accounting for the largest share of cases. Claims were reported across a wide variety of breeds and sizes, suggesting susceptibility is not limited to specific types of dogs.
The American Heartworm Society estimates that more than one million dogs in the United States are currently infected with heartworm disease and recommends routine testing alongside year-round preventive medication.
Information sourced from the company’s press release.
