Hyperthyroidism has been linked to pet foods that include the thyroid glands of slaughtered animals. Because pet food consumers are not informed of what portions of slaughtered animals are used in pet food, knowing the symptoms of hyperthyroidism could be important to protect your pet’s health.
Recently I heard from a pet food consumer whose healthy dog started to have a dry, ragged coat and showed some aggressive tendencies towards other dogs. This pet owner sent Dr. Jean Dodds some blood for testing and the results showed the dog’s thyroid levels were nearly 4 times normal. Four times normal thyroid levels could have resulted in stroke or blindness or even death.
This dog had previously been fed a home prepared raw diet, but ten months prior to the finding of extremely high thyroid levels the owner changed the dog to a commercial raw beef diet. And it happened that this dog’s thyroid levels were checked just before the change to the commercial raw beef diet – at that time they were ‘low normal’.
Dr. Dodds suggested to the pet owner to remove the current pet food. The owner did, went back to the home prepared locally raised raw meat pet food as was used before, and in two months time this dog’s thyroid went back to normal.
In ten months time, this dog’s thyroid levels went from low normal to a dangerous 4 times normal. Two months after removing the suspect pet food, the dog’s thyroid levels were back to normal. Why?
We can safely assume it is diet related hyperthyroidism.
Hyperthyroid issues can be caused by a tumor on the thyroid gland, an error in medications, or it can be diet related. Diet related hyperthyroidism is linked to pet foods or treats containing the thyroid gland of slaughtered animals. The big problem for consumers is – we are not informed if the pet food/treat we purchase contains the thyroid gland of slaughtered animals.
The research available on this shows this is more of a concern for dogs than cats (but note the research is very limited – it is unknown if cats are at the same risk for diet related hyperthyroidism).
Dr. Karen Becker wrote on this issue in 2014 – quotes from her post…
In a 2012 study published in the Journal of Small Animal Practice,1 12 raw fed dogs were evaluated for elevated plasma thyroxine (thyroid hormone) levels. Six of the dogs had symptoms of hyperthyroidism, while six had no clinical signs. After a change in diet, 8 of the dogs’ thyroxine levels returned to normal and their symptoms resolved.
The study authors concluded that:
“Dietary hyperthyroidism can be seen in dogs on a raw meat diet or fed fresh or dried gullets. Increased plasma thyroxine concentration in a dog, either with or without signs of hyperthyroidism, should prompt the veterinarian to obtain a thorough dietary history.”
Dr. Mark E. Peterson – a veterinary endocrinology specialist – shared the following insights on dietary hyperthyroidism in dogs…
“In man, community-wide outbreaks of “hamburger thyrotoxicosis,” resulting from inadvertent consumption of ground beef contaminated with bovine thyroid gland, have been previously reported (3,4). These outbreaks resulted in the banning of “gullet trimming,” in which meat in the neck region of slaughtered animals is ground into hamburger. Because thyroid tissue is similar in color to muscle meat, it is possible for gullet trimmers to include the thyroid gland when meat is ground into hamburger or sausage. People, and presumably pets, that eat such contaminated hamburger or gullet tissue can ingest doses of thyroid hormone sufficient to induce disease.”
It is significant to note that the thyroid gland is banned from human consumption (ground in hamburger meat) – thus we know it ends up in pet food. But again, consumers are not told which pet foods include the thyroid gland that could put our pets at risk.
The few pieces of science published on this issue all discuss raw pet foods as the risk of diet related hyperthyroidism. It is assumed this is because raw pet foods contain more meat than typical kibble or canned pet foods (thus could contain more thyroid tissue). But…it is my guess that raw pet foods are not the only risk. Any pet food that contains large levels of thyroid glands of slaughtered animals could pose a risk to the pets consuming them.
What can consumers do?
One – call or email the manufacturer and ask if thyroid glands are included in any meat ingredient of the pet food.
Two – know the symptoms of hyperthyroidism. Dr. Mark Peterson states the symptoms of canine hyperthyroidism are: weight loss, aggressiveness, tachycardia (rapid heart rate), panting and restlessness. If you notice these symptoms in your pet, consult your veterinarian immediately.
As the AAFCO meeting will be coming soon, this will be an issue that I ask regulatory authorities about – to label the thyroid gland as a separate ingredient in order to alert consumers. In the meantime, all consumers can do is to ask questions of your pet food manufacturer and pay close attention to your pets.
Wishing you and your pet(s) the best,
Susan Thixton
Pet Food Safety Advocate
Author Buyer Beware, Co-Author Dinner PAWsible
TruthaboutPetFood.com
Association for Truth in Pet Food
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Dianne
January 6, 2016 at 3:26 pm
I will have to check with the whole carcass foods to make sure the thyroid is not included. I wonder if any other glands have similar effects.
Beth Marousek
January 6, 2016 at 3:42 pm
Do we know if the thyroid gland’s hormone is rendered harmless by the high heat used in preparing canned and dry food, which would make these foods exempt from this problem? Sounds like it was an issue with hamburger, but maybe that wasn’t cooked thoroughly.
Susan Thixton
January 6, 2016 at 4:15 pm
No – I don’t believe cooking eliminates the issue. There is also concern of dogs eating trachea treats that include the thyroid gland – these treats are dried prior to sales.
Sherrie Ashenbremer
January 6, 2016 at 8:11 pm
Do any of the foods on your dog food list have this in it? OR should we call the company. I have five dogs, one of them eat Just Food for Dogs (venison and squash) he is an allergy dog. The others eat Evermore Raw diet and Orijen.
Yoo Jin
January 7, 2016 at 9:34 am
Does this include only beef? No chicken, turkey, venison, pork?
Susan Thixton
January 7, 2016 at 9:37 am
I’m by no means an expert on this issue – but from my understanding there is a greater risk with beef or larger slaughtered animals. This is because the thyroid gland is larger – thus the pet would be consuming more of the thyroid hormone.
DIana Artemis
January 7, 2016 at 9:04 pm
Hyperthyroidism has been proven to be associated with flame retardants in furniture, draperies, carpets and clothing as determined by biopsies of the thyroid glands of affected animals.
Susan Thixton
January 7, 2016 at 10:24 pm
There is a new study – just read about it today – that is saying “The researchers tested cat food and blood samples from cats. They also simulated how a feline’s body would process various PCB- and PBDE-related compounds. Based on their results, the team concluded that the byproducts that were detected at high levels in cats’ blood samples likely came from fish-flavored food and not exposure to PCBs or PBDEs.” I haven’t read the full study yet – just this write up on it. Here is the link: http://phys.org/news/2016-01-fish-flavored-cat-food-contribute-feline.html
Heather
January 8, 2016 at 1:07 pm
Thanks for this info, Susan.
If this helps others –
I emailed both Nature’s Logic and Primal Pet Foods and asked if their raw frozen foods contained thyroid gland.
Nature’s Logic response: “They do not.” (Note, I specifically asked about the Chicken and Rabbit formulas only.)
Primal Pet Food’s response: “Because we incorporate the use of only Human Grade sources of nutrition, we are prohibited from incorporating the use of the thyroid gland into any of our meats, and have refrained from doing so in all of our products.” (Note, I specifically asked about their feline formulas – Pheasant and Rabbit – and also asked about their treats.)
Lisa
January 8, 2016 at 2:56 pm
Wish we knew which commercial raw beef product caused the problem. 🙁
Debbie
January 8, 2016 at 4:01 pm
i am going to ask what others will ask and I am shocked they havent yet, What pet food was it she fed that caused this to happen?
Phyllis Russo
January 10, 2016 at 10:40 pm
In your list you recommend several raw food companies. Do any of them use the thyroid gland in their foods. I noticed RadCat uses organs as well as muscle. How do I know that they do not use the thyroid gland?
Thanks for always sharing such important information.
Susan Thixton
January 10, 2016 at 10:47 pm
I know several do not – have not had the opportunity to ask each of them yet.
Phyllis Russo
January 11, 2016 at 11:14 am
So, you are putting your top picks that you would only feed your own pets AND you wrote an article on a serious problem, but you don’t know if Your top picks that we as readers and as those who have given money to this cause of the healthiest foods we can feed our cats, and let me get this clear, you don’t know which ones on your list of 2016 uses thyroid tissue? I know I can ask the company, but my name would not carry the weight that your’s does, so any of these companies can lie to me, but they would certainly be hesitant to do that to you. You’re going to lose your “fear”status to them if you don’t investigate this on your TOP companies and lose our trust who depend on you to do this for us.
Susan Thixton
January 11, 2016 at 2:47 pm
Phyllis – I learned of this issue AFTER the companies were selected for The List. Well after. I learn of new concerns in pet food often. And I do other things than contact pet food companies and ask questions – such as going to an AAFCO meeting next week (which includes a boat load of preparation). There have been weeks when I’ve had a meeting (phone) with AAFCO and/or FDA every single day of the week. There is only one of me – I can’t be everywhere and do everything. I investigate issues and share those investigations with consumers. Everyone is responsible for their own pet food decisions. The List are foods that I personally trust – if that doesn’t work for you, I understand.
I’m a bit insulted by you stating “fear status” – do you think I sit here day in and day out just to make consumers fear pet food? If so, that is very wrong. I offer education about the industry to help them not be afraid – to help them make informed choices. And by the way – pet food companies can (and have) lie to me just as easily as they can lie to you.
I could have lied to you and said none of the foods on The List use thyroid material – but I didn’t. I was honest. Again – there is only one of me – and I try my best every single day. That’s the best I can do.
Phyllis Russo
January 11, 2016 at 3:37 pm
I meant “fear” status to the companies. Not to the consumers. I meant to say they know you mean business as opposed to just one of us consumers.
And I know you wouldn’t lie. It just sounded like you didn’t research this part of it and I and other consumers depend on you. The comment after yours has helped. And yes you are well appreciated and I know your work is important. That is why I hold you to a higher calling.
Susan Thixton
January 11, 2016 at 3:48 pm
Your response is appreciated Phyllis. But just to be clear – I don’t want pet food companies to fear me, or fear any consumer or advocate. I want them to respect us. To me, there’s a big difference between the two.
Phyllis Russo
January 11, 2016 at 3:52 pm
understood.
Heather
January 11, 2016 at 3:25 pm
@Phyllis –
Note how the use or inclusion of the thyroid gland is PROHIBITED in human grade/intended for human consumption meat. Just as Susan mentions in the article above and also what Primal’s representative mentioned in their email response to me (above).
So it’s not that difficult to figure out – meat intended for human consumption is USDA inspected and approved (as explained in this article https://truthaboutpetfood.com/ah-but-there-is/). Which means, those meats cannot contain thyroid gland.
If a raw pet food company uses either Human Grade/USDA Inspected meats in their formulas, by adherence to that existing ban, thyroid gland cannot be included, right? At least that’s what I’m gleaning from it.
I looked at RadCat’s website for you. They say this about their meat sources:
“It is important to us that all of the meats we use come from farms that practice sustainable agriculture. Our organic chicken, free-range turkey, pasture-raised lamb and grass-fed beef are US sourced and our pasture-raised venison comes from New Zealand. All meats are USDA inspected, and are hormone and antibiotic free. All meats we use are the very same cuts that are found in fine supermarkets. On our label, we list the actual cuts of meat we use.”
From that quote, I’d say it’s safe to assume RadCat does not use thyroid gland – if anything, simply because they can’t by way of using USDA inspected meats. The same cuts “found in fine supermarkets.”
For comparison, I checked Nature’s Variety site. Here’s what they say (or try not to say?) :
“All of the materials used in our raw diets and raw frozen bones are obtained from USDA-inspected facilities (or meet USDA requirements in the case of imports) and from animals that have passed ante- and post-mortem inspection. Our quality control and quality assurance programs include but are not limited to: Sanitation Standard Operating Procedures (SSOP’s), Good Manufacturing Practices (GMP’s), a Hazard Analysis & Critical Control Points (HACCP) program, regular lot segregation, and other industry best practices. That said, our manufacturing facilities are used to produce pet food rather than human food, and since this is not in line with the USDA’s definition of human grade, our foods cannot be classified as being human grade.”
From that quote, I’d suspect Nature’s Variety might have thyroid gland included – simply because of their use of the words, “USDA inspected facility” and not ‘USDA inspected meats.’ If I fed that food, I’d have emailed to ask them directly.
So to know for sure, take a few minutes and send the companies of the foods you feed/have fed an email – like I did after reading this alert. We as consumers and animal guardians have as much responsibility to do due diligence on our part. We can’t expect Susan to do everything for us – she does a TON for us already! 🙂
Phyllis Russo
January 11, 2016 at 3:39 pm
Thanks for clearing this up. Well appreciated. If you noticed there is a lot in your comment to digest, which is why I asked for a simple answer. I know she does a lot for us. I am just holding her to a high standard.
Martin Ellis
January 28, 2016 at 11:58 pm
Has the lining of pet food tins- especially. pop-top cans with plastic containing BPA ever been connected with hyperthyroidism? I have noticed in New Zealand supermarket pet food that all the pop-top type cans that I feed my cat have a plastic type coating.
Over the years I have had 3 cats with hyperthyroidism and all have lost weight, had high thyroid blood test results, heart problems(murmur, impaired kidney functions – a very expensive problem, that shortens their lives and costs owners thousands of dollars.
Have you ever heard of this link to BPA.(Bisphenol A)
catherine
April 19, 2016 at 6:39 pm
The place I’ve gotten some of my raw food (Hare Today – representative emailing me back was Tracy) had this to say when I contacted them about this issue just a couple of days ago, as I had some of their gullet in my freezer. Which no where on the package does in say “might or does” contain thyroid gland or tissue, nor can I find that disclaimer on their website at this time. Tracy emailed: “We do use the gullet in the grinds of beef, goat and sheep so it may have thyroid gland in it but I find a couple things important to point out in the article. From article:
“In the dogs of this report, it is obvious that the correct balance was not maintained and a very large amount of raw thyroid gland tissue ended up in their raw meat diet.” she goes on to say,”This was a comment from a poster (on the article Dodds? posted) and I find this relevant.
“It would have been interesting to know which diet these dogs had been eating, and whether they were eating just the beef diet or getting a well rounded diet of a variety of protein sources. You don’t want to throw the baby out with the bath water!” (but she had just said, they put it in many of their various protein grinds…beef, goat and sheep… wouldn’t people buying those different proteins, be trying to strive for a well rounded diet and not just getting “beef”? That made no sense to me as she points out the fallacy of feeding just beef and the benefits of a well rounded variety of protein sources – which they provide, yet they put gullet in those too.
She believes that because the study did not quantify how much they were given in their diet – that the study is “flawed” (“Feeding some gullet will not cause hyperthyroid in a dog. The article is so flawed. Does not even say how much or how long this was feed.”)
However how does Hare Today know how much is too much to have in any given product, that they can so easily dismiss the fact that their products contain it and at least give fair warning to customers? Might take a lot or just a little – could be breed specific, size specific etc. A lot of breeders are going raw and extra thyroid hormone in their breeding dogs is NOT good.
I simply bought a package or two of just gullet so I can easily discard it, but if they grind it in with many of their grinds…they say they don’t put extra gullet in a whole animal grind, but they certainly do carry just packages of nothing but gullet – so some “whole” animal is not getting ground up as she stated below…and what becomes of the packages of just gullet that don’t sell – think they just toss it at a loss? She went on to state more of her thoughts on the article Dodd posted on the studies: “My Thoughts:
Since we grind whole animals [except beef leg bones] there is one gullet/throat per animal so the proportion of a thyroid gland in that entire animal is miniscule. We do not add extra thyroid glands to any mix period. If you follow mother nature and use the ratios of a prey animal I do not believe this article would be relevant. The key again is a varied raw diet and if someone is feeding large amounts of anything this is not an appropriate diet.” So, to answer someones question above – this is one company that does include it in their raw pet foods. I’d just like to see that mentioned on product page or pkg from all raw providers – as I came across this potential problem just recently – had no idea I needed to watch out for thyroid gland in raw foods for dog.
catherine toornman
April 19, 2016 at 7:30 pm
Hare Today Gone Tomorrow – has several grinds that contain the thyroid gland. Have been talking with Tracy via email on this subject for the past two days. She says among other things… “that the studies are flawed” because they don’t tell how much the dogs were actually getting… sent her screen shots of the PubMed studies (4) which were in jpg format and can be enlarged if she dropped them on her desktop – she said too tiny send link so I looked them up again and sent actual link to four different studies – was barely 11 minutes after I send the link to the studies that she wrote back – “Those links do not state what % or ratios or how much. I still stand behind what I said”. I’d love to share the rest of the emails with you as some of what she said blew my mind – but that would entail typing it all out again – as I tried to post it to you earlier and it looked like it posted but clearly it did not as I don’t see it up here…
Shannon
February 11, 2019 at 9:16 pm
Love some help please. My dog was diagnosed with thyroid cancer last May. Based on how progressive it was, his age, his size and the fact that the mass is mot movable he was given a short time frame to live. He has continued to survive. However I’m seeing very progressive signs of hyperthyroidism lately. His appetite is insatiable and he’s losing a lot of weight and has bad bowel movements majority of the time. He’s on a wonderful kibble Open Farm but also has a harder time with the hard kibble and I’m desperate to find the best possible food for him for the last of his days. And I’m open to making it but are there certain foods specifically that would help him keep weight on and improve his bowel movements, like kale, fruits, which proteins?