CAPC 2026 Forecast Highlights Growing Parasite Risks for Pets and Humans

According to CAPC, the geographical spread of these diseases is projected to extend into regions previously classified as low- or moderate-risk. The organization noted that its forecasts are based on over a decade of data analysis from more than 10 million veterinary diagnostic test results each year, achieving 94% accuracy in past predictions.

Kathryn E. Reif, PhD, MSPH, a CAPC board member and associate professor of parasitology at Auburn University, stated that the shifting risk of vector-borne diseases is influenced by factors such as land use changes, pet travel, wildlife movement, and climate change. These forecasts aim to assist veterinarians in enhancing preventive measures, customizing vaccination strategies according to local risks, and promoting regular testing for pets.

Lyme disease remains a significant concern for 2026, with black-legged ticks expanding into new geographical areas. High-risk zones include the Upper Midwest and Northeast, while projections indicate possible spread into Ohio, Kentucky, West Virginia, Tennessee, North Carolina, Indiana, Illinois, and Michigan. CAPC pointed out that regions with a heightened risk for canine Lyme disease often coincide with human Lyme disease cases, highlighting the interconnectedness of pet, human, and environmental health.

The forecast also emphasizes the ongoing threat of heartworm disease, predominantly established in the Southeast. The disease is expected to continue spreading northward along the Mississippi River and the Atlantic coast, with some elevated risk areas remaining in the Mountain West and Northern California. According to CAPC, factors such as large dog populations, expanding mosquito habitats, urban development, and inconsistent preventive measures are contributing to heartworm transmission.

Ehrlichiosis and anaplasmosis risks are projected to increase as the ranges of lone star ticks and brown dog ticks expand. CAPC anticipates persistent ehrlichiosis risk across the Southeast, Southwest, and South-Central U.S., along with a northward movement of lone star ticks into the Upper Midwest and New England. Increased risk associated with brown dog ticks is also expected in the Southwest and Mountain West. Notably, these tick species can transmit pathogens year-round, meaning that risk is not limited to traditional tick seasons.

Craig Prior, BVSc, CVJ, a CAPC board member, advised that "low risk does not mean no risk," emphasizing the necessity for year-round prevention and annual testing for pet owners. CAPC Executive Director Chris Carpenter, DVM, MBA, noted that the forecast provides veterinarians with a proactive framework for anticipating risks rather than merely responding to them.

In addition to the forecast, CAPC offers tools such as 30-day parasite forecast maps and daily flea forecasts at PetDiseaseAlerts.org, which assist veterinarians and pet owners in monitoring local parasite threats and adapting prevention strategies accordingly.