The American Heartworm Society (AHS) unveiled its 2022 Heartworm Incidence Map, and the latest edition reveals a growing trend in infection rates throughout the United States.
The map—which the AHS produces every 3 years—provides the veterinary community with data on the location and prevalence of heartworm infection in the United States based on reporting from thousands of practices and shelters. This map reflects data collected in 2022 from a survey distributed early this year.
The 2022 Heartworm Incidence Map once again reflects that the lower Mississippi Delta region is particularly vulnerable.
“The states with the highest density of diagnosed heartworm cases in the latest survey were Mississippi, Louisiana, Texas, Alabama, and Arkansas,” AHS president Jennifer Rizzo, DVM, stated in a media release. “Meanwhile, Arkansas, Mississippi, Texas, Georgia, Florida, Tennessee and the Carolinas all saw expansions of high-density areas on our incidence map.”
The AHS surveyed participants and asked if infection rates have changed since 2020. More than half (53%) of the respondents reported that rates have remained consistent, 29% reported an increase, and 17% reported a decrease.
Reasons for an upward tick in rates included: an increase of heartworm-positive pets in the area (29%), client compliance with heartworm preventives (27%), and weather changes fostering a positive environment for mosquitoes (22%).