Scientific Results: Environmental exposures and health outcomes in dogs differ according to geographic region in the United States among Dog Aging Project participants

Author

Janice S. O’Brien

Where was it published?

American Journal of Veterinary Research Issue 30 Jun 2025

 What is this paper about?

This research looked at how where a dog lives in the U.S. affects the kind of exposures it faces and the types of health problems it gets. Our team used data from the Dog Aging Project —which collects questionnaires from dog owners—to see if dogs in different parts of the country have different environments and health outcomes.

What we did:

1. Surveyed owners: Our team examined answers from 47,444 dogs across the U.S., gathered from January 2020 to December 2023.
2. Grouped locations: Dogs were grouped by U.S. census regions—Northeast, Midwest, South, and West.
3. Compared exposures: Our team compared things like yard pesticide use, types of home heating, what water dogs swam in, etc.
4. Compared diseases: Our team also looked at how common certain diseases were in each region.
5. Used statistics: Our team calculated percentages and confidence intervals to see which differences were real and not just random.

What did we find?

Environment Differences by Region:

Dogs live differently depending on their environment—for example, they may be exposed to different chemicals in the yard, types of water, or heating sources in the home.

Dogs also get different diseases depending on where they live:

• More infections in the Northeast
• More dental problems in the West
• More skin issues in the South
• Other conditions like cancer, neurological issues, and digestive problems were fairly similar across all regions.

What didn’t change:
Dogs’ general activity levels didn’t vary much between regions.

What do these results mean for me and my dog?

This study is like a health map for dogs across the U.S. It helps owners, vets, and scientists understand how geography and environment shape pet health—so everyone can work together to keep dogs (and people!) healthier.

Thus, where you live changes what your dog is exposed to and what health problems they might face.

• If you live in the Northeast, you might need to watch out for more infections, like tick-borne diseases.
• If you live in the West, focus on dental care – talk to your vet about preventive care.
• If you live in the South, be extra careful about skin health—watch for signs of itching, allergies, and pests like fleas.
• The Midwest and other regions have their own patterns, too, so it’s important to be aware of your local risks.

It helps you take better care of your dog by focusing on the health issues they’re more likely to face based on where you live. It also helps you make smarter choices about your dog’s environment—like what products you use at home or where you let your dog play.

*If you have concerns about your dog’s health, we encourage you to discuss these concerns with your primary care veterinarian. Suggestions for a treatment plan are best recommended by the veterinarian who has a relationship with your dog and understands their medical history.

Where can I learn more?

O’Brien JS, Grzywinski M, Sexton CL; et al. Environmental exposures and health outcomes in dogs differ according to geographic region in the United States among Dog Aging Project participants. Am J Vet Res. 2025 Jun 30:1-10. doi: 10.2460/ajvr.25.04.0121. Epub ahead of print. PMID: 40588169.

Abstract

Objective: To determine which environmental exposures, lifestyle variables, and prevalences of health conditions within the Dog Aging Project population differed by geographic region.

Methods: For this cross-sectional descriptive study, owner-reported environmental and lifestyle factors from 47,444 individuals enrolled in the Dog Aging Project cohort from January 1, 2020, through December 31, 2023, were examined across census regions, and 95% CIs were computed for each individual factor across the regions.

Results: Analyses indicated high variation in the characteristics of dogs’ environments across the US regions, including both inside and outside of the home. Certain types of diseases disproportionately affect dogs in some regions: infectious diseases were most prevalent in the Northeast (49%; 95% CI, 48% to 50%), dental disease was highest in the West (46%; 95% CI, 45% to 47%), and skin conditions were most prevalent in the South (45%; 95% CI, 44% to 45%). Dog activity levels did not vary significantly across regions.

Conclusions: There are regional differences in lifestyle and environmental exposures experienced by companion dogs across the US, such as pesticides and weed treatments applied to yards, swimming water sources, and home heat sources, whereas other exposures do not differ across regions. The prevalence of some health conditions, like infectious/parasitic diseases, dental disease, and skin conditions, varied by regions, whereas others, like cancer, neurologic, and gastrointestinal diseases, showed no regional variation. These findings inform future hypothesis-driven studies of environmental health risks of dogs, which are relevant to translational research.

Clinical relevance: There are regional variations in exposures that may contribute to differences in the prevalence of health conditions found in companion dog populations.