By Linda P. Case
Modern-day dog chews and treats are all the rage. Contrary to what their marketers would have you believe, the majority of these goods are simply new variations on a tried-and-true concept: turning animal parts that we typically discard as waste because they are inedible into pricey and frequently highly sought-after dog treats. Bully sticks, pig ears, pig/cow hooves, cod skins, and the subject of this essay, beef gullets (esophagus) and tracheae, are just a few examples. Some commercial and home-made raw diets include the entire neck regions of beef, lamb, chicken, turkey, and other food animals in addition to being available in dried form as a chew.
The Concern Is: Can dogs safely eat tracheae (necks) and gullets?
The response: Not if the thyroid gland tagged along.
A brief anatomy lesson: The thyroid gland is a tiny organ that surrounds the top of an animal’s trachea. The trachea and esophagus are removed as by-products when a cow is dissected to produce human-grade meat. These animal parts can be used in pet foods even though a law passed in 1986 forbids their inclusion in human foods, which is exactly where they end up (along with other animal by-products that are deemed unfit for human consumption).
Thyroid Tissue in Your Dog’s Food: The hormone thyroxine is found in thyroid tissue, which is resistant to the dog’s stomach acid and digestive enzymes. It is absorbed into the body and remains active. When a dog consumes enough thyroxine through diet, the dog develops hyperthyroidism (or, to be more precise, thyroidtoxicosis), which results in an increase in the level of thyroid hormone in the blood. Some canines experience elevated serum thyroxine levels without exhibiting any symptoms. Weight loss, hyperactivity, excessive panting, and polydipsia/polyuria (increased drinking/urinating) are some of the symptoms that some people experience.
So, should pet owners be concerned about this issue? Possibly, especially if you feed a raw diet. Here is the evidence:
- Twelve dogs were fed raw diets in 2012, and German veterinarians at Justus Liebig University discovered that these animals had higher plasma thyroxine levels when either fed a raw diet or a lot of fresh or dried beef gullet (1). Half of the dogs had clinical signs of hyperthyroidism (6/12). Seven owners stopped feeding gullet after receiving a diagnosis, and they immediately switched to a commercial dry food. Veterinarian rechecks two weeks and two months later showed that all dogs’ plasma thyroxine concentrations had normalized and their clinical symptoms had disappeared. One owner did not change her dog’s diet. One and four months after the dog’s diagnosis, repeated thyroid hormone tests revealed elevated levels, and the dog was losing weight steadily. The owner then changed the dog’s diet, and the dog’s clinical symptoms disappeared along with the plasma thyroxine levels returning to normal.
- Two more cases: Two cases were reported in 2014. In the first, a male Rottweiler puppy who was 11 months old was checked for indications of weight loss, excessive panting, and elevated blood thyroxine levels (2). A thorough analysis of the dog’s diet revealed that it was being fed a commercial raw diet. The dog’s symptoms disappeared after switching to a commercial dry food, and its blood thyroxine levels were normalized. A two-year-old female Miniature Pinscher was examined in a second case study for failing to enter estrus (3). The dog was given a home-made raw diet that included cuts of beef from the head and neck obtained from a nearby butcher shop. The dog had highly elevated serum thyroxine levels. Serum thyroxine levels and estrus cycles in the dog were brought back to normal after changing its diet.
- Recent research on thyrotoxicosis in 14 dogs fed either a commercial raw diet or a variety of chews or treats was recently published in the Journal of the American Veterinary Medical Association (4). Each treat was a different variety of sliced or rolled jerky chew. Within four weeks of stopping the suspect products, clinical symptoms disappeared and thyroid hormone levels returned to normal. Seven samples of the brands of food or treats that owners were giving their pets were made available to the authors. When compared to control foods, all had elevated thyroxine levels. The authors conclude by saying that the problem of thyroid tissue contamination of such items may be widespread and not limited to only a few products or manufacturers because high T4 concentrations have been found in a variety of pet foods or treats sold under different labels. “(The authors also sent samples and product identification data to the FDA for additional investigation)”
Takeaway for Dog People: Let me make it clear right away that these research findings are in no way presented as a personal vendetta against feeding raw to dogs, lest raw feeders flood my blog with venom and unleash the trolls.
Those of you who have read 
rel=”nofollow” target=”_blank”>Dog Food Logic know that my position is that there are many approaches to feeding dogs healthfully, and a well-balanced, properly selected (and sourced) raw diet can be one of those approaches.
Evidence, however, strongly suggests that the recent rise in diet-induced hyperthyroidism is most likely a result of both the popularity of raw diets and the practice of giving dogs unusual chews like gullets and tracheae. This collection of case studies offers sufficient proof that diet-induced hyperthyroidism poses a health risk, at the very least, to justify further research and examination of the named businesses and brands.
Draggin’ out the ol’ box: Fear not. I do have a personal opinion on this (although I’m not quite ready to call it a vendetta yet) This relates to information from the 2015 study, which was gathered in the United States. At the time of diagnosis in that study, all 14 dogs were being fed commercially prepared food. These were products that the owners bought from a business, believing that they would not only give their dogs good nutrition but also be SAFE. This shouldn’t be such a difficult standard to meet, but the pet food industry consistently seems to find it to be.
Here’s the thing: It’s not news that eating foods containing animal thyroid tissue can result in hyperthyroidism. Because of well-documented outbreaks of diet-induced hyperthyroidism in people, “gullet trimming” as a source of ground beef was banned in the 1980s. However, we are still permitted to feed our companion animals foods that contain these tissues. Why is this?.
I contend that dog owners should have easy access to information about the ingredients in the pet foods they give their canines, including the type and source of the protein ingredients. However, requests for this information are frequently ignored, denied, or answered with evasive platitudes and assurances. Ask the manufacturer of the pet food you feed if they guarantee that it doesn’t contain thyroid tissue and if the food contains animal necks. Let me know what you hear back.
In an ideal world (and when I’m queen), we’ll outlaw feeding our canine family members food containing unsafe body parts. I know it’s a ridiculous idea, but hey, a person can dream, right?
Got Gullet? Let’s hope not.
Cited References:
- Kohler B, Stengel C, Neiger R. Dietary hyperthyroidism in dogs. Journal of Small Animal Practice 2012; 523:182-184.
- Daminet, S., De Roover, K., Paepe, Hesta, and S. Cornelissen Dietary hyperthyroidism in a Rottweiler. Vlaams Diergeneeskundig Tijdschrift 2014; 83:306-311.
- Sontas BH, Schwendenwein I, Schafer-Somi S. A Miniature Pinscher buck developed primary anestrus as a result of dietary hyperthyroidism. Canadian Veterinary Journal 2014; 55:781-785.
- Broome MR, Peterson ME, Kemppainen RJ, Parker VJ, Richter KP. Exogenous thyrotoxicosis in dogs caused by eating commercial dog treats or all-meat dog food that contains too much thyroid hormone: 14 cases (2008–2013) Journal of the American Animal Hospital Association 2015; 246:105-111.
Beef Gullet Chews for Dogs (Closed Captioned)
FAQ
What is beef gullet made of?
Made from beef esophagus that has been flattened into a strip after being split down the middle. Key Advantages: This chew is particularly tasty and a good choice for picky dogs because it is a good source of easily digestible protein.
Is beef gullet safe for dogs?
Nutritional Benefits Gullet sticks are very easy for dogs to chew and gnaw on, making them a great option for picky puppies, small dogs, senior dogs, dogs with dental problems, dogs with arthritis, and younger dogs.
Is beef gullet the same as bully stick?
Gullet sticks are firm, yet slightly pliable. It is hollow and tubular in shape, but not as dense as a sturdy bully stick.
Can people eat beef gullets?
Review The trachea and esophagus are removed during the dissection of cows to produce meat fit for human consumption, and they are then used as by-products. These body parts can be used in pet foods and treats even though they cannot be sold as foods for human consumption.