Scientific Results: Testing for heavy metals in drinking water collected from Dog Aging Project participants

Author

Courtney L. Sexton

Where was it published?

PLOS Water

 What is this paper about?

Our team tested the drinking water of dogs who live in homes served by wells. We wanted to see if the water contained potentially harmful metals like lead, arsenic, and copper. This study was an important pilot study, which means it was a smaller, preliminary investigation designed to explore a research question before launching a larger-scale study.

Study Size and Scope:
We invited 200 dog owners from the Dog Aging Project to participate in the study. These participants were from 10 U.S. states and included every region across the U.S. Out of those invited, 178 households sent back samples of their dogs’ drinking water for testing. These homes didn’t use city water (which is regularly tested) but relied on private wells, which aren’t regulated. We tested for 28 different metals, including 8 heavy metals that the EPA keeps an eye on because they are known to be dangerous to people if levels get too high.

What we discovered:
Almost every water sample had some level of metals. In fact, 64% of the samples had at least one metal that was above the safe levels set by the EPA. We noticed a possible link between contaminated water and dog health, which might also indicate risks for humans if they are also drinking from the same water source as their dogs. Dogs that drank water treated only with basic filters were more likely to have a health condition, while those with reverse osmosis systems had fewer health problems. But because as we mentioned this was a pilot project with a small sample, we need to investigate these possible links further.

Our team plans to expand this research with a bigger and more diverse group to better understand how water quality affects dog and human health in different regions and among different communities.

What do these results mean for me and my dog?

Your dog’s health is a window into your environment. This study shows that clean water matters, and small changes may make a big difference. You don’t need to worry—stay proactive:

1. Know where your water comes from: If you use a private well, consider testing your water. It’s easy and affordable.
2. Upgrade your filter if needed: Basic filters can be helpful, but might not remove all harmful metals. Consider getting a reverse osmosis system; they tend to be more effective.
3. Watch for subtle signs: If your dog has ongoing health problems and you use well water, it might be worth checking the water quality.
4. Stay informed: Your participation in studies like this helps improve health for pets and people alike.
5. Talk to your vet: Share this info with your veterinarian, especially if your dog has chronic health problems.

*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?

Sexton CL, O’Brien J, Lytle J, Rodgers S, Keyser A, et al. (2025) Testing for heavy metals in drinking water collected from Dog Aging Project participants. PLOS Water 4(8): e0000296. https://doi.org/10.1371/journal.pwat.0000296

Abstract

Heavy metals are commonly found in groundwater and can affect the quality of drinking water. In this pilot study, we analyzed the quality of drinking water for dogs participating in the Dog Aging Project (DAP) who lived in homes not served by a municipal water supply. In order to capture both diverse and localized environmental factors that may affect drinking water, 200 owners of DAP dogs located in one of 10 selected states were invited to participate. We tested for the presence of 28 metals in dogs’ drinking water, including eight (8) heavy metals that have maximum contaminant levels (MCLs) designated by the Environmental Protection Agency (EPA) and five (5) heavy metals that have EPA health guidance levels. The eight metals with MCLs are known to cause chronic health issues in humans after long-term ingestion. Our aim in this pilot was to determine whether such elements could be detected by at-home sampling of dogs’ drinking water, and, using regression models, to examine associations between water source variables, metal values, and developed disease. We found detectable levels of all metals tested. There were 126 instances when an analyte (arsenic, lead, copper, sodium, strontium, nickel, or vanadium) was above the EPA MCL or health guidance level. We further identified potential association between the presence of titanium and chromium, and occurrence of a known health condition in dogs. This prompts further investigation with a larger, stratified sample analyzing dogs’ drinking water composition and long-term health and wellness outcomes in dogs living in diverse geographies. These results may impact veterinary care decisions and husbandry, and underscore the validity and importance of utilizing dogs as sentinels of human health outcomes in the context of drinking water contamination.