If your normally sweet natured dog has suddenly become snappy or even unexpectedly aggressive, you naturally wonder what’s going on.
So, you take him to the vet to rule out any illness or injury. Your vet does a physical exam and can’t find anything that might be causing pain or discomfort. and they suggest putting him on anti-anxiety medication to see if that helps.
But you feel there must be another reason for your dog’s behavior change … and you’re probably right.
What many vets may not consider is the possibility that your dog’s suffering from hypothyroidism.
Hypothyroidism And Its Causes
The thyroid is a butterfly shaped gland in the neck that regulates the metabolism of the body’s cellular functions by producing hormones such as thyroxine (T4). Hypothyroidism occurs when the thyroid doesn’t produce enough T4.
Dr Jean Dodds and Dr Marty Goldstein are two leading veterinary experts in thyroid issues.
Dr Dodds states that in nearly 90 percent of cases hypothyroidism is an autoimmune disorder. According to Dr Marty Goldstein, autoimmune thyroiditis happens when the body mistakenly interprets its own thyroid gland and hormones as foreign threats. The body then produces antibodies to destroy the functional thyroid gland cells, resulting in loss of function.
Though some breeds are genetically predisposed towards hypothyroidism, Dr Goldstein says environmental factors also play a role: chemicals in medicines, flea and tick products, heartworm drugs and vaccines are all environmental triggers for autoimmune reactions.
Dr Goldstein also describes secondary hypothyroidism, which involves three glands – the hypothalamus, pituitary gland and thyroid – that work in conjunction with each other. The pituitary gland secretes TSH (thyroid stimulating hormone) that stimulates the thyroid to function. But the pituitary gland gets its “orders” from hormones released by the hypothalamus so these three glands can’t work properly without proper input from the others; the thyroid might be normal, but is not receiving the messages it needs to function.
Dr Dodds warns that a tight or prong collar on a dog who pulls a lot can also cause extensive thyroid damage so using a harness will avoid injury when walking him.
The classic symptoms of hypothyroidism are familiar to many: weight gain, sluggishness, bad skin, hair loss and dislike of the cold. If we saw these symptoms, we’d probably think about getting our dog’s thyroid tested. These are the symptoms veterinarians are trained to look for too.
But according to Dr Jean Dodds, these classic clinical symptoms don’t occur until 70 percent of the thyroid is already damaged! And once the thyroid is damaged, it doesn’t regenerate. So, instead of waiting for these symptoms to appear, it’s really important to recognize the early symptoms that may indicate a damaged thyroid.
So, getting back to the grumpy dog we talked about at the beginning of the article … it turns out that a key early symptom of thyroid damage is – guess what – behavioral problems!
Adult dogs who suddenly start snapping are a good example of the kind of change you might observe. Your dog might start being fearful out of the blue, or displaying aggression. You might see submissive or obsessive compulsive behaviors.
Dogs who gain weight when they’re not being overfed (known as idiopathic obesity) are also displaying early symptoms of thyroid damage.
You might also see changes in your dog’s face. The eyes may look different, the brow can look furrowed, or you may even see a cleft above the eyes. Dr Dodds recommends taking regular photos of your dog so you can see the changes that take place!
So if you see a sudden behavior change in your dog, perhaps along with some weight gain without any change in diet, it’s a very good idea to have your dog’s thyroid tested.
What To Ask For
The right kind of testing is important when diagnosing hypothyroidism. Be careful! Many vets will just test the T4 level and diagnose based on that alone.
Both Dr Dodds and Dr Goldstein warn that the T4 test alone is useless because it can be affected by many other factors such as diet and medications. Diagnosis should never be based on T4 alone.
Instead, make sure you get a complete thyroid antibody profile, measuring at least T3, T4, Free T3, Free T4, and TgAA. If your vet doesn’t offer a full thyroid profile, ask her to draw the blood for you and send it yourself to Hemopet (Dr Dodds’ diagnostic laboratory – visit hemopet.org for more information) or another lab that offers this testing.
If your dog is diagnosed with hypothyroidism, there are many natural therapies that may help before resorting to conventional synthetic thyroid replacement.
Be sure to consult a holistic vet about dietary changes as well as nutritional, nutraceutical and glandular therapies that can support your dog’s thyroid function.