Hypothyroidism is an under-diagnosed condition in both veterinary and human medicine. There are lots of gray areas, partly due to the fact that thyroiditis is a remitting-relapsing disease like so many other immune-mediated diseases. You can be normal on one test and your results can be in the basement on another. The thyroid glands are very resilient and can bounce back from insults (e.g. Hashimoto's thyroiditis) but will ultimately succumb if the underlying cause is not addressed.
The role of lectins (e.g. antibody-sized proteins/glycoproteins from gluten, dairy, corn and SOY) is well-established. After all of my reading, I believe that thyroid disease is like so many other immune-mediated ("autoimmune") diseases in which an underlying VIRAL response to the insults being thrown at the various tissues is the true pathomechanism for the development of the condition. In other words, viruses in the cell (some of which are embedded in our very DNA) react to the challenge by lectin attachment or by chemicals/"carcinogens" and induce either hypothyroidism (Hashimoto's thyroiditis) OR hyperthyroidism (Graves disease).
Interestingly, dogs ONLY develop hypothyroidism except in the rare case of a thyroid carcinoma. Cats ONLY develop hyperthyroidism and many of them actually develop a thyroid tumor, which makes sense due to the fact that viruses cause tumors/cancer. Humans on the other hand develop BOTH. (This is really interesting when we consider that many of the viruses we acquire that causes disease originally came from animals and that animals do not share each others viruses in most cases.)
Put "virus, thyroid" in your search engine and you will see what researchers know and believe. Interesting.
But, not all thyroid illness is from immune-mediated disease. A study in dogs done by a colleague of mine showed something important. He took a large group of dogs that were clinically hypothyroid and had low thyroid lab tests to match and treated them all with kelp, a good natural source of iodine. One third of them recovered both clinically and in their lab values without any formal thyroid hormone supplement. This fits with what I have come to see and speaks to the malabsorption syndrome being induced by the "big 4" foods...gluten, dairy, soy and corn...with iodine being one of the nutrients that is normally absorbed by the duodenum but that is NOT being absorbed properly due to the villous atrophy caused by these foods.
In most cases, it would be a combination of these two factors...malabsorption of iodine and a true immune reaction in the thyroid gland. Celiacs (gluten intolerants) have a 40-50 times higher rate of Hashimoto's and Graves, with the latter being a BIG red flag to indicate the need for celiac testing. But, SOY is a major goitrogen and is now driving the rates of thyroid disease through the roof. Google "soy, thyroid" and you'll be amazed.
There are numerous tests available for thyroid function. Sadly, most vets and MDs do the minimal tests. One of the best test panels includes all of the thyroid hormones (T4, free T4, T3, Free T3), TSH, and thyroid autoantibodies. The latter help to determine whether the individual is forming antibodies to their thyroid hormones. TSH has been a horribly over-used and unreliable determinant of thyroid health. For example, we now know that the classic situation of high TSH (thyroid stimulating hormone released by the pituitary gland) is NOT always present in hypothyroidism. In some cases, low thyroid function is due to low production of TSH by the pituitary gland. On the other hand, hyperthyroidism is usually more cut and dried, with the results predictably matching symptoms.
Bottom line? Read between the lines when thyroid testing is done. There is a lot of controversy surrounding the lab's normal ranges in both veterinary and human medicine. Many of us believe that the low end of normal (e.g. T4, free T4 and T3) is too low. If corrected, this would potentially change the diagnosis in a large number of cases. I am thoroughly convinced that there are many individuals out there who need thyroid medications that simply can't get diagnosed properly (Google "Edna Kyrie" of
www.thyroidresearch.com )
So, ask for your results and check them against the normals. If you think you could be hypothyroid, interpret the results accordingly. If you are in the gray range (low end of normal), you may very well be hypothyroid. We now know in veterinary medicine that a thyroid supplement trial in these gray cases is NOT a harmful thing to do. We used to think that giving thyroid meds to an individual who didn't need them would do irreversible harm to the thyroid glands. We now know (mainly from our recent experience with the meteoric rise in hyperthyroidism in cats...due to wheat and soy in their diets) that the thyroid glands are MUCH more resilient than that. In fact, they are amazingly so which actually gets a bit frustrating when dealing with hyperthyroidism.
Thyroid illness is very common and we need really to use our brains when dealing with it. And as we've stated, it is also a big player in non-responsive epilepsy as well as in pain perception and immune competence.
I hope this helps,
John
