Is There Mercury In Pet Food?

mercury in pet food

Make no bones about it, mercury is dangerous. But if you feed kibble, you could be feeding it to your dog, day after day, month after month, year after year.

That’s a huge problem. You’ll see why in a bit. 

There’s a lot of research about high levels of mercury in pet foods, especially foods with fish in them. And the FDA doesn’t have standard levels for safety in dog food, so there’s no watchdog looking out for your pets.

So how much mercury is in the food you’re feeding your dog? A new research project plans on answering that question.

New Research Into Mercury In Pet Food

A few years ago, researchers at the University of Nevada, Reno tested wet and dry dog and cat foods for mercury. Mercury is a notoriously difficult metal to study, but that didn’t stop the project from succeeding. And the supervision of internationally respected scientist Dr Mae Sexauer Gustin didn’t hurt either. The study uncovered some interesting, and troubling, data …

… And it has prompted the researchers to head back to the lab. 

I spoke with Dr Sarrah Dunham-Cheatham, a postdoctoral scholar involved in the current project. Dunham-Cheatham and her colleagues will test mercury in pet food and see if labels tell us the whole story about actual ingredients.

Dr Sarrah Dunham-Cheatham and her colleagues

1. What is the Pet Food Mercury & Genetics Experiment?

The Pet Food Mercury & Genetics Experiment is a crowdfunded research project. It’s based at the University of Nevada. It will be broken into 2 parts:

  1. Determining how much total mercury and methylmercury are in cat and dog foods
  2. Investigating the accuracy of pet food package labels

Our goal with this project is not to attack the pet food industry. It’s about finding the truth. We want to make people aware of what’s in the food they’re feeding their pets.

We don’t have any corporate sponsors or investment in the final results. We’re seeking the unbiased, unsponsored truth about what is in our pets’ foods. We’re simply after the factual data.

The information can also be useful for pet food manufacturers. Our hope is that they’ll use the data to change their formulations, making pet food safer.

2. What motivated you to carry out this important research?

In 2016, Adriel Luippold was awarded a small University research grant. She used it to conduct an experiment under the supervision of Dr Mae S Gustin. Because they were both pet lovers, they decided to look at mercury in pet foods. Adriel analyzed 101 pet foods for total mercury. She found that 16 of the foods contained mercury at levels above the tolerable limit. Adriel and Dr Gustin published their results in 2016.

This year, with a new team, we’re revisiting the original study and taking it a few steps further. There are a few reasons for this:

  1. Pet food recipes and ingredient sources change through time. This means the results of our 2016 study likely won’t reflect the foods that are on the shelves today.
  2. Another popular study (the Clean Label Project) corroborated our results last year. They looked at heavy metals in pet foods and found high concentrations of mercury in some foods. This tells us mercury in pet foods is still an issue.
  3. The majority of the 16 offending samples in our study contained tuna. Tuna is a notorious mercury-containing fish so this was of particular concern to us. Tuna not only contains high levels of mercury, but most of it is in the methylmercury form. Methylmercury is a potent neurotoxin. Small doses can cause adverse health effects in animals and humans. Cats, in particular, are extremely sensitive to low concentrations of mercury and methylmercury. If cats are eating these foods regularly, they could be eating high levels of mercury and methylmercury.

Mercury and methylmercury build up in the body over time. As a result, consuming even small doses with each meal can add up quickly. This can have a disproportionate long-term effect. When you consider that most pets eat the same food for every meal, day after day, it becomes a concern.

The genetics part of the project was brought about by Dr Gustin and Dr Michael Teglas. Dr Teglas is Associate Professor in University of Nevada, Reno’s Department of Agriculture, Nutrition & Veterinary Sciences. Together they decided to test their pets’ foods for DNA composition. They were curious if the ingredients in the food matched the ingredients on the label. They also wanted to see if the high cost associated with some meat sources was worth the money.

One of the pet foods they analyzed was labeled as “duck and potato.” The DNA results indicated that duck was indeed in the pet food. But so too was sheep though “sheep” was not included anywhere on the pet food label. Given these results, we decided to test for accuracy of packing labels in a variety of pet foods. This certainly erodes trust in the pet food industry. It also complicates things for pets with food allergies or sensitivites. If an owner isn’t aware of what’s in a food, pets could be eating things they shouldn’t be. This is a concern.

3. What exactly are you testing?

We will be testing total levels of mercury in pet foods. We’re also doing the DNA composition.

Pet foods will be ground and lyophilized (the fancy science word for “freeze-dried”). This removes the water from the samples. Then we split the samples up:

  • One portion will be analyzed for total mercury concentration.
  • Another will be chemically digested and analyzed to test for methylmercury concentration.
  • A third portion will be used to extract DNA. This will determine which animal proteins are present in the food.

4. What are the biggest dangers of mercury and methylmercury?

Mercury is a potent neurotoxin. It affects the nervous system, among other systems and organs, in both humans and animals.

Exposure to inorganic mercury may result in a range of symptoms, including:

  • headaches
  • dermatitis
  • muscle twitches
  • tremors
  • weakness
  • decreased brain function
  • kidney and respiratory failure
  • death

Exposure to organic mercury (including methylmercury) may result in:

  • vision impairment
  • loss of coordination
  • weakness
  • neurodegenerative conditions
  • ataxia (loss of control of body movements)
  • death

Symptom severity depends on dose and duration of exposure. 

[RELATED] Want to know more about the dangers of mercury poisoning? Check this out.

5. How long do you think the research will last?

Once we’ve raised the funding we need, the entire project should take  about 6 to 12 months to complete. If we receive funds above our $25,000 goal, we’ll analyze more samples. We will continue the project until we run out of money.

Our deliverables will include:

  • Total mercury and methylmercury data
  • DNA results

We will share these results on our Facebook page. We will also publish them in peer-reviewed journals.

6. What is unique and special about this project?

This project is unique because it’s entirely crowdfunded. Most scientific research is funded by governments, agencies or donors. This project relies 100% on the pet loving public to be successful. That means that we don’t have any investment in the outcomes. We’re dedicated to unbiased, transparent results.

This project is also special for the training and research opportunities it provides both undergraduate and graduate students. It’s also an open conversation between the public and the scientists collecting data. This is a portal that the public doesn’t commonly have easy access to!

7. How can people donate? And where does their money go?

Donations are being collected through our University of Nevada, Reno Foundation webpage. The webpage is secure. We chose to collect funds this way because there’s no overhead. This means 100% of every donation directly supports this research project. Every donation is also tax deductible. 100% of the money will be used to support the above analyses of pet foods. Any additional funds raised will be used to buy and analyze more pet food samples.

I want to sincerely thank Dr Dunham-Cheatham for chatting with me about the Pet Food Mercury & Genetics Experiment. We can’t wait to see the results. 

You can find out more about the researchers and the project at their Facebook page here.

If you’re interested in donating to this important project, visit the Foundation page here.

5 minutes a day. Healthier Dog.

Get important health plans from vets & experts. It’s natural and it’s free.


Get instant access to easy-to-make and affordable recipes. Plus get new recipes delivered right to your inbox.

Recipe Cards for Making Raw Dog Food

Related Posts