Posted on: December 9, 2022 Posted by: Petsynse Comments: 0

Why collars can cause hypothyroidism and other health problems


Learn about better alternatives

Before you start reading the following lines, I invite you to do a little test. Open your hands with your thumbs touching each other. Place your thumbs at the base of your throat and with your fingers pointing back and surrounding the neck.

Now, take a deep breath, squeeze and pull back with all your force keeping your thumbs connected.

This is how many dogs feel when they are pulling on their leash that is attached to a collar.

If you are still keen to continue with this experiment, put a choke chain around your neck, attach it to a leash and ask a friend to pull and jerk on it periodically. Welcome to the dog world!

No, I will not make you go on with this experiment and ask you to test a prong collar or electric shock collar. I just want people to be more aware of what the average dog deals with.

My plan is to share with you why I believe collar injuries make dogs sick and what the alternatives are.


One day, my previous dog, Skai, and I were walking in Capilano Canyon, our favorite walking area near our home in North Vancouver, British Columbia, Canada.

The wild river has carved the rocks into breathtaking scenery, with moss-covered cliffs, whitewater rapids and giant old-growth rainforest fir trees.

Just a few minutes after starting our walk, I noticed a man with a young German Shepherd on a leash. The poor little pup was struggling to say hi, however, his human had a different idea. He was determined to prevent his dog from coming closer to us by yanking and jerking harshly on the leash that was attached to a choke chain. With every yank, I caught myself closing my eyes, cringing and feeling terribly sorry for the poor dog. He was coughing and gagging with every jerk and had no idea what was going on.

Suddenly the voice in my head whispered: “Peter, you must say something, this poor dog is helpless.” The voice went on, “Maybe the man is not even aware of what is going on.”

“Excuse me,” I started with hesitation. “You may not be aware of this, but the choke chain you are using can cause a life-long injury and damage, and I thought you may want to know why.”

“Thank you, that would be great,” the man replied. “I would love that. I had no idea.”

Origin of collars and their effects

No one really knows when the use of collars started. Perhaps it was the way the cave people restrained their wild dogs from running away. However, the first reference to dog collars comes from Ancient Egypt.

The reason why I am so weary of collars is that when dogs pull they can cause a lot of damage. The neck and cervical spine are one of the most important energy channels in the body. The spinal cord supplies the whole body. The front leg nerves originate from it and it is the energy channel where the nerves controlling the internal organ function pass through. The thyroid gland regulates the whole body’s metabolism and is located in the neck.

For years, I have observed the relationships between neck injuries and the health of dogs. I have learned that when the flow of energy in the neck is interrupted or restricted, a whole array of problems may arise including lameness, skin issues, allergies, lung and heart problems, digestive issues, ear and eye conditions and thyroid gland dysfunction, to name a few. I also suspect that if a patient has severe energy flow congestion in the neck area, they have higher cancer rates.

The purpose of this article is not to give you a long description of each condition, but I would like to give you a few examples to help you understand how important the health and alignment of the neck is to the general health of your dog.

Low levels of thyroid gland hormone may be caused by collar-related injuries

For the longest time, I have been puzzled about the high rates of thyroid issues in breeds that frequently pull on the leash, such as  Labrador Retrievers and German Shepherds. It seems obvious that collars push on the throat in the exact area of the thyroid gland. This gland gets severely traumatized whenever a dog pulls on the leash, it becomes inflamed and is consequently destroyed by the body’s immune system when it tries to remove the inflamed thyroid cells.

The destruction of the thyroid cells leads to the deficit of thyroid hormone – hypothyroidism and because the thyroid gland governs the metabolism of every cell it can affect the whole body. The symptoms may be low energy, weight gain, skin problems, hair loss and a tendency to ear infections and organ failure.

Ear and eye issues are frequently related to pulling on the leash

When dogs pull on the leash, the collar restricts the blood and lymphatic flow to and from the head. My clients are often perplexed when all the ear and eye problems disappear after switching their dog from a collar to the right harness.

Excessive paw licking and foreleg lameness can also be related to your dog’s collar

Leash pulling impinges the nerves supplying the front legs. This can lead to an abnormal sensation in the feet. As a result, dogs may start licking their paws. These dogs are often misdiagnosed as allergic, when removing their collar and treating the neck injury is all that is needed.

Neck injuries can cause a variety of problems including emotional trauma

Some dogs suffer severe whiplash-like injuries from being jerked around. Extension leashes do not help because they encourage dogs to pull. They face an imminent jerk when they get to the end of the line. They also do not understand why they are being ‘punished,’ which often makes them shut down, disconnect or act out their frustration with aggression.

Most people do not know that leashes and collars can be at the core of many problems and that just one incident of pulling or running fast to the end of the leash can be serious. So how can we reduce the risk?

A harness – the collar alternative

Over the years, I have searched for the best way of making dogs safe and have tried many harness systems to prevent neck injuries. Well-fitted harnesses that have both a front and back attachment are the best solution because they distribute the pressure of tugs and jerks throughout the whole body, while keeping the neck and throat free of pressure. 

Many harnesses on the market that have the leash attached to the back still restrict the front portion of the neck when a dog is pulling, thereby pressing on veins, arteries, nerves and energy channels. 

When you get your dog’s harness, making sure that you have the right fit is key. 

Using both the front and back attachments together will offer the most control, balanced distribution and safety, especially for dogs who are strong or pull on leash. For dogs who do not pull, we have found that using only the front clip is a suitable option to use at your discretion.

Use the harness only when leash walking and take it off when your dog is off leash. Ensure that the harness is not pressing or rubbing anywhere and that it is washed regularly.

Ideal solution

If your dog is adequately trained, give him as much off leash time as possible. If you have a ‘puller’, have his neck examined by a vet, physio or chiro experienced in neck assessment. You may want to get his thyroid levels and the neck and back checked for any signs of injuries. Keep in mind that many veterinarians are not trained in checking spinal alignment and working with the right practitioner is essential.

If you are looking for gentle and effective treatment methods, homeopathy, physiotherapy, intramuscular needle stimulation, chiropractics, acupuncture and massage are the best choices.

Remember that ideal muscle and spinal balance also depends on the body receiving essential nutrients. 

Recommended reading:

One “jerk” can cause a lot of damage 

Holistic treatment of hypothyroidism in dogs

© Dr. Peter Dobias, DVM