QUESTION: “Our healthy 5-year-old greyhound just had baseline labs done, and we were all shocked to find her T4 level off-the-chart high. Range is .8 – 3.5, and her value was 8.8. She does not have any symptoms of hyperthyroidism. Greyhounds often have low thyroid conditions, not high. Our holistic vet asked if her diet includes neck bones, which they do. She probably eats 3 or 4 neck bones a week, turkey or lamb. Apparently she could be ingesting a thyroid gland or hormones. Has anyone heard of this risk? We are eliminating neck bones for one month and then will retest. If it’s not diet related, she thought it might be a tumor. I hate the thought of that. – Michele, Thursday, January 28, 2016”
ANSWER: Hi Michele, Thanks for posting this interesting question! It’s a good topic to review.
I am glad to know she does not have any symptoms of hyperthyroidism, but because this value was so high without any symptoms, I would first suggest running the test again now to make sure there wasn’t an issue with the test itself before you make changes to the diet. She may certainly be one of the dogs that is experiencing dietary induced hyperthyroidism (which is easily reversible, thankfully!), but you’d want to be sure the test is accurate as it is still quite rare.
Yes, newer research has indicated an association between the regular feeding of necks, trachea/gullets and/or head meat, either fed raw or given as dried treats, and hyperthyroidism in some dogs. Hyperthyroidism is incredibly/terribly commonplace and prevalent in cats; but not so for dogs – most dogs with thyroid disease exhibit symptoms of/will be diagnosed with hypothyroidism (underactive), not hyperthyroidism (overactive).
The feeding of neck bones (chicken, lamb, beef, etc) is incredibly common and popular in raw feeding, as these bones are some of the safer options for RMBs– soft/not weight bearing, easy to find and easy to feed – but there is this new research that shows an association with a possible risk of hyperthyroidism. The information we have so far is from some rather small samples of patients and we have been feeding a lot of raw necks/tracheas/gullets to lots and lots of dogs for many years without seeing this as a major issue/risk…but, obviously, for some dogs (perhaps with an underlying predisposition or perhaps when this is the only or predominant RMB being fed?) this is a problematic food that should be avoided or at least minimized through feeding more variety (indeed, completely eliminated & avoided until the tests results are back to normal).
The good news is that 100% of the dogs that had elevated levels/hyperthyroidism while consuming head meat, necks or gullets all reverted back to completely normal once these possibly gland-tainted bones were replaced with other RMB options.
I concur with the following analysis and good suggestions from Dr. Becker about this topic – this is another issue that proves feeding a wide variety of different foods is vitally important (no matter what you are feeding) to avoid overdoing any specific nutrients or causing even rare dietary imbalances such as this:
“To avoid diet induced hyperthyroidism in your raw fed pet, my recommendation is to make sure you are feeding a variety of protein sources and cuts of meat (thigh meat, etc.) so that your dog isn’t eating a steady diet of raw meaty bones/necks that could contain active thyroid tissue.
If your pet is a healthy, raw-fed dog, it’s not necessary to go out of your way to avoid foods that may possibly contain thyroid tissue. The studies I mentioned above involve a very small number of dogs that I suspect were eating the same cuts of meat (necks) for a prolonged period of time. Thankfully, their hyperthyroid conditions were easily reversed with a simple dietary change, but this study reinforces my belief that pets need a variety of different meat sources (and body parts) for overall health and wellbeing. So if you’ve been feeding poultry necks regularly as the foundation of your dog’s raw food diet, consider changing up your recipe to include other cuts (wings and backs) and diversify your protein sources.
I also recommend you keep an eye out for symptoms of hyperthyroidism (and any other possible illness) in your pet, and see your veterinarian for regular wellness checkups that should include measuring your dog’s blood thyroid hormone levels.”
Even though it is a rare condition, I hope it is indeed from the necks and that, after making an adjustment to her RMB selections, her values will revert back to normal. I hope it’s not a tumor, too (even though this is the more common reason for hyperthyroidism in dogs).
Along these lines, it is important for all raw feeders (cats & dogs) to be sure to not overfeed iodine containing foods such as kelp/seaweed and even too much fish. Remember: variety is key & everything in moderation! Kelp is an excellent, and even necessary, part of a balanced raw diet, but feeding far too much of it can cause problems with thyroid health. Just be sure you are following a good dietary guide, never overdo any single component or ingredient, and try to not get into a rut of feeding the same things endlessly/over & over – this is, again, another reminder of why it’s SO important to mix it up!
Lastly, if you feed the very same thing to a population/sample of dogs (or cats), over time, we know that select individual animals are going to respond in unexpected ways to foods that work nicely/are well tolerated by the majority – for example, dietary hyperthyroidism is something I would consider somewhat rare and not usually a risk for most dogs.
Finally, when considering thyroid health risks, another thing to consider is trauma to the neck from collars and other equipment –the use of certain collars have shown an association with damage to the thyroid gland (and trachea). It is best to avoid these types of collars, IMO: http://peterdobias.com/blogs/blog/11015137-choke-prong-and-shock-collars-can-irreversibly-damage-your-dog
Hope this helps!
UPDATE: Feb 2, 2016
Just to follow-up on the inquiries about the thyroid/glandular tissue on the trachea, gullet or GreenTripe products that include these ingredients. This is a question/concern (not a dog that actually had the condition but just an inquiry about the risk) that came up within our group a few years ago, actually and they get this question from time to time. I talked to them about it a few years ago, but I confirmed everything again with them today:
The USDA slaughterhouse they source their ingredients from is instructed to remove all glandular tissue before they get the product. In addition, GreenTripe does their own inspection of their ingredients, with removal of any extra tissue possibly attached to the trachea/gullet at processing or packaging. While the proximity of these tissues to these body parts may possibly allow for minute levels of contamination, these parts do not have any glandular tissue attached when sold or used in processing. Lastly, in all the years they have been selling these products they have not had a single incident of a dog that experienced a change in their regular panel laboratory tests/exam results related to the inclusion or exclusion of these foods and thyroid function/health.
I also got confirmation that the USDA inspected beef, lamb, chicken, turkey, duck, etc. necks we sell are cleaned of all glandular tissue at processing. We do not source necks that would possibly have this tissue attached. But again, due to proximity of these parts to the glands, minute levels may possibly be consumed in this way. I cannot possibly imagine that it would be enough to cause diet induced hyperthyroidism from these specific foods/cuts — *maybe* possible in a dog with an existing sensitivity and if necks were being fed as the only source of RMB for an extended period of time and/or fed in excess.
Sourcing is key! For example, in one of the case studies that was pointed to in the report I posted earlier – this was a study with a sample of just TWO dogs, living in the same household, that were getting whole heads from a local slaughterhouse which caused the thyroid condition. Not USDA-inspected meat. I cannot find the sources for the meats in the other two small sample studies, but I do wonder if this was USDA inspected meat fit for human consumption or animal feed grade, or from animals butchered at a small local facility that slaughters/butchers animals for personal or CSA “direct-to-consumer” use only (not for retail sale/not USDA inspected). One of the studies referenced this condition being related to the regular feeding of dried gullet/trachea pet treats– these were not USDA inspected products. There is a difference.
Please understand that I do not find the small direct-to-consumer non-USDA slaughter/butcher/processor option necessarily problematic at all (this is how MOST high quality local producer-run CSA or “direct to consumer” operations manage their processing) but for this specific issue, there would be a possibility of getting the whole animal back with all parts attached after processing at one of these facilities, or for them to give someone free/cheap scraps for their dogs that would contain these tissues. Whereas this is simply not possible when a rancher/producer sends their animals to slaughter in a USDA facility and have the parts USDA inspected for human consumption/resale. This is tightly regulated by the USDA, and it is the reason why we can’t get some really cool parts we’d like to from our current suppliers. Many people don’t understand that the rancher has to buy back the meat from their own animals after processing from the USDA slaughterhouse. They simply can’t get back the whole animal broken down into all the tissues/parts 100%, even if they wanted to – they can only get USDA-inspected and permissible parts in return and many times they struggle to get even basic offal like liver, kidney, and hearts.
BUYER BEWARE Unfortunately, many commercial pet foods on the market can & do use meat that is not USDA inspected. I have seen a lot of them that claim ingredients from a “USDA facility” and this generally means the food and meat used has not actually been inspected & approved by the USDA (“USDA inspected”). This practice appears to have caused diet induced hyperthyroidism in at least once case cited on a blog (see link). The dog’s levels went back to normal after being 4x the norm when put back on a DIY home-prepared raw diet: http://truthaboutpetfood.com/diet-related-hyperthyroidism/ This is only one of the many safety and quality issues I have with pet food ingredients that are not “fit for human consumption” and/or USDA inspected and approved.
SFRAW does not sell ANY products that would fall under this category with the exception of two pet food producers we have worked with for many years and trust completely:
1) GreenTripe (pet food sourced meats/cuts from USDA facility, under special USDA-orders, that we have confirmed are directed to remove this tissue & re-inspected by GreenTripe at processing)
2) Hare-Today whole prey and whole ground animals. The whole prey will include the whole animal with all glands/fur/feathers. I think these are great products and a wonderful option for those willing to feed this way. Over the years, I have feed my own animals a lot of these foods, in rotation with other foods (Remember: moderation and VARIETY is the best way to reduce risks of all sorts!)
As a CDFA licensed and inspected pet food manufacturer, and by our own code of ethics and standards, the SFRAW Grinds & Formulas use only 100% USDA inspected “human-grade” meats & parts with this tissue removed.
That being said, it will be interesting to learn how Michele’s Greyhound, Lexy, does after her change in diet and re-testing. I hope she reverts back to normal quickly. It would be very good news if it were a sensitivity this individual dog has that caused diet induced hyperthyroidism because it is completely reversible and her dog will be ok with a switch to wings, backs, etc. and removing any neck region foods from the diet (any commercial foods that may contain ingredients from the neck/head region or using meats that are not 100% “USDA-inspected”, Xkaliber, GreenTripe with Trachea & Gullet, Hare-Today whole animal grinds, whole trachea or gullets, dried trachea or gullet treats, and all neck bones or heads).
Hope this helps with those concerned or those that just enjoy learning more about this topic.
UPDATE: Oct 28, 2016
After a trial of changes to her diet and retesting to evaluate her thyroid health, we last heard from Michele that Lexy was eventually diagnosed with hyperthyroidism after all. Her veterinarian and family concluded that Lexy had been experiencing thyroiditis in Jan and that the necks, etc. in her diet were not the primary cause of her unusual laboratory findings. They are happy to report that they were given the OK to include more necks in her diet (her favorite) and she continues to feel and do great! We’re so happy to hear this news for Lexy and Michele! And, for others that were concerned, this conclusion removes a direct link/blame of her lab results on the feeding of necks and GreenTripe products and shows that she actually had an underlying thyroid disease (common in her breed) that is now being managed and treated.
Hope this helps those wondering about this topic to make more informed choices when feeding a natural diet to their dogs!
RELATED QUESTION Tuesday, March 14, 2017
ANSWER: Hi Aaron, This condition is INCREDIBLY rare! In fact, it is so rare, that I’ve only know of one single dog in the history of my raw feeding experience (since 1989) that experienced a related issue. Upon taking her off the neck bones and GreenTripe with Trachea & Gullet, her values did improve immediately. However, she then became hypothyroid, and it was determined that she was just a dog with a problematic thyroid disease. They determined that it was far more of an issue of her own body, than her diet or exposure to iodine or thyroid issues. Here is another great article about this topic: http://healthypets.mercola.com/sites/healthypets/archive/2014/11/04/hyperthyroidism-dogs.aspx
All of the meats used in SFRAW Grinds & Formulas are 100% USDA licensed and inspected food that is 100% fit for human consumption, which means it is not at high risk for contamination with glandular tissue.
In addition, all of our raw meaty bones sold at SFRAW (not including GreenTripe or Hare-Today pet food products) are also 100% USDA licensed and inspected food for humans to eat, and have been cleaned of glandular tissue according to the USDA guidelines and the amount, if any, would be absolutely minuscule.
Our Chicken, Duck, Turkey and Rabbit Grind & Formulas include the entire whole bird or rabbit. When we can, we include the necks and heads and feet — these parts are not always available, but we try to get them, and include them, when we can because I think they provide additional nutritional benefits.
Our Lamb, Beef and Pork Formulas & Grinds do not include any heads or necks/neck tissue at all – below please find the ingredients used from the animal(s):
LAMB = Lamb Trim, Lamb Heart, Lamb Tongue, Lamb Breast Bones, Lamb Liver, Lamb Kidney.
PORK = Pork Bnls/Snls Leg, Pork Heart, Pork Tongue, Pork Liver, Pork Spleen, Pork Kidney, NOW Brand Bone Meal Powder.
BEEF = Beef Bottom Round, Beef Heart, Beef Tongue, Beef Liver, Beef Spleen, Beef Kidney, NOW Brand Bone Meal Powder.
The beef is the only one that could possibly include gullet and trachea (these parts are exclusive to beef/ungulates) — but they are not used/present in our ground foods.
If you buy our stuffed, dried or raw beef tracheas that we offer, you may be feeding some minuscule amount of glandular tissue. We think this is safe for 99.999% dogs.
BTW: the dog that experienced the hyper-t was eating a diet of kibble, and she was given turkey, duck and lamb neck bones for her RMBs, and fed GreenTripe Xkaliber or GreenTripe with Trachea & Gullet. As far as I know. she did not feed SFRAW Grinds or Formulas. She has since gone back to feeding some of the previous foods as her issue was resolved and has been managed with medication – see above for full details!
Hope this helps!
Sincerely and in good health to you and Daisy,
2 thoughts on “Q&A: Feeding Necks & Hyperthyroidism in Dogs”
Please correct that Lexy had Hyperthyroidism and not Hypothyroidism.
Done! I just copied and pasted from your original email — how interesting. I thought she had hypo-t form your email. How is she doing these days? Thanks for the correction – I didn’t know!
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