NSights Blog

How much mercury in popular dog and cat foods? The numbers are surprising

Crowdfunding effort to take next step in better understanding how much mercury is in pet food

If you are like 70 percent of U.S. households, you have either a dog or a cat as a pet, which means that you likely visit pet stores or aisles frequently. If you are like us, you stand in the aisle overwhelmed by the number of choices. How are you supposed to pick one? What criteria do you use to select the product you will take home to (insert adorable pet name here)? Do you select the most affordable? The most expensive? Middle of the road? A well-advertised brand, or a boutique brand? Surf or turf? Something based on a friend's recommendation? A veterinarian's? Do you steer clear of the recently recalled pet foods and brands with ongoing lawsuits over heavy metal contamination? However you decide, are you confident that you know what is inside the packaging and that the product you have selected is safe for your pet?

Two years ago, our research team started to help consumers answer just that. Studies have shown that some pet foods contain hazardous metals in varying amounts. As experts in mercury science and analyses, we were curious to know how much mercury was in popular dog and cat foods. Mercury is a potent neurotoxin and can have adverse effects on animals, including muscle twitches, tremors, weakness, decreased brain function, kidney and respiratory failure, and death in extreme cases. Currently, the Food and Drug administration only has recommended maximum tolerable limits for non-reproducing cats, which is 267 nanograms of mercury per gram of food, and reproducing cats, which is 67 nanograms per gram. Using these limits as a baseline, we analyzed 101 dry and wet dog and cat foods, and found that five of the pet foods had mercury levels that exceeded the limit for non-reproducing cats. The highest concentration we measured was 604 nanograms per gram! We also found that an additional 11 pet foods contained mercury levels above the limit for reproducing cats. The full results from our study can be found in Animal Feed Science and Technology's article, "Mercury concentrations in wet and dry cat and dog food."

What do our results mean for the health of our fur babies? It is not a simple answer. Our study quantified the total amount of mercury in the pet foods, but mercury comes in many different forms. The toxicity of mercury depends on the form, with pure mercury being the least toxic and organic mercury forms, or molecules containing both mercury and carbon, being the most toxic. Methylmercury and dimethylmercury are two examples of organic mercury compounds and are common in fish tissues routinely incorporated in pet foods.

To be honest, we were hoping that our results would show that all the pet foods we analyzed would not have any appreciable mercury, but that was not what we found.

This summer, our research team embarked to dig even deeper into the pet food mercury issue. We launched a crowdfunding campaign to help raise money to cover the costs to analyze more than 100 pet foods and treats. Our objectives for the project are to determine the total amount of mercury and methylmercury in pet foods and treats, and share our results with the public so that pet owners can be better informed when selecting products for their pets. As scientists at the University of Nevada, Reno, experts in the field of mercury analyses and fellow pet owners and lovers, we want to help consumers make a more informed decision when purchasing foods and treats for their pets. But we need your help!

Donations to the project can be made through the University of Nevada, Reno Foundation. All donations are tax deductible, and 100 percent of donated funds will be used for research on this issue. Donations will provide research opportunities for undergraduate and graduate students.

Our goal is to raise $10,000. This amount will cover the purchase of 50 pet food samples (we have already received 50 pet food donations), as well as the analytical costs to determine the total mercury and methylmercury concentrations in the samples.

This project will be completed under the supervision of 2018 Nevada Board of Regents Researcher and Foundation Professor Dr. Mae Gustin; College of Agriculture, Biotechnology, and Natural Resources Associate Professor Dr. Mike Teglas and Extension Educator Dr. Lindsay Chichester.

Help us help you keep your fur babies happy and healthy!

Read the article: https://www.sciencedirect.com/science/article/pii/S0377840116309257

Ask questions to Sarah: sdunhamcheatham@unr.edu

Follow on Facebook: www.facebook.com/PetFoodMercury

Adriel Luippold and Sarrah Dunham-Cheatham