The thyroid gland has many magnificent functions, and it was while studying these functions, that I started to contemplate yet another possible function of the thyroid, a function, that to my knowledge no one else has discussed, the thyroid's ability to ever so slightly disinfect the blood.

Before I continue this article let me state one thing. What I suggest here is my opinion only. There are no scientific papers, that I could find, which support my theory. Having said that, let me continue.

Every few minutes, all the blood in a pigeon completely circulates through the body. The thyroid gland, which is supplied by arterial flow, interacts with the blood as it circulates, selectively absorbing iodine (actually iodide ions) from the bloodstream and storing the iodine for the future production of thyroid hormones.

Though Iodine is found throughout the body, the concentration of iodine in the thyroid gland is about 1100 times greater than that found in any other part of the body. Approximately, 20% of all the iodine present in the body is concentrated in the tiny thyroid gland.

As blood circulates through the Thyroid gland, it passes across a network of follicles sticking out into the blood flow. You might almost visualize its structure as resembling gills on a fish only on a microscopic level. This vast network of follicles greatly increases the epithelial surface area allowing maximum iodine extraction from the blood flow.

What we have then, is a tremendous amount of surface area confined within a tiny chamber (the thyroid gland) and this tiny chamber containing concentrations of iodine 1100 times greater than that found in any other part of the body. I believe with every pass of the blood through the thyroid gland and across this network of follicles, that a minute but perceptible disinfection of the blood takes place. Hundreds of times a day, blood cycles through the thyroid gland and with every pass, residuals of the high concentrations of iodide ions, weaken pathogens circulating in the blood.

The thyroid follicles do not just scoop iodine out of the bloodstream and whisk that iodine into some storage vat. Rather, iodine is attracted to the surface of the follicles by an electrochemical imbalance in the epithelial cells of the thyroid follicles. During the absorption process, there are higher concentrations of iodine on the epithelial lining of these follicles than in the blood and certainly more than found in most tissues of the bird's body. In this very small filtration chamber, blood flow is exposed to the highest concentrations of iodine present anywhere in the body.

For those of you who are now suspecting that I have been smoking nest bowl materials again, let me point out that a preferred method for disinfecting water systems is to pass the water through a series of iodide-impregnated resin filters. As the water passes through the iodide-impregnated resin filters, the water comes in contact with the iodide and this process has been shown to kill even the many species of bacteria and viruses present in human feces.

If iodide-impregnated resin filters can successfully kill many species of bacteria and virus (even those found in human feces), I believe the same mechanism might also work on the blood supply as it circulates through the thyroid gland hundreds of times a day.

You might say that the thyroid gland is filled with iodide-impregnated thyroid follicles that function somewhat like the water filter example above. Since the blood passes through the thyroid gland hundreds of times a day, the tiniest amount of disinfection is multiplied by hundreds of passes a day.

Am I suggesting that the thyroid gland is the disinfecting organ of our birds? No, only that in my opinion, iodide-impregnated thyroidal follicles act to gently disinfect the blood supply as it circulates through the thyroid gland.

A word of caution, iodine is a trace mineral, and should be administered to your birds "only in trace amounts". Please do not go out and start dosing your birds with iodine based on this article. There is a reason why iodine is a trace mineral, to much iodine in the system and your birds may develop hyperthyroidism or even tumors. If you are using mineral or vitamin supplements for your birds you will be fine as both of these products usually contain proper trace amounts of iodine.

In the next issue, we will discuss how Iodine is required for the synthesis of the thyroid hormone, thyroxin, which among other functions, regulates the rate of metabolism and affects protein synthesis. In part three of the series, we will examine how one "so called" safe treatment, used in most lofts today, might actually contribute to the breakdown of immune response in our birds. In order to better understand part three of the series, we will need to review materials that most of us slept through in high school chemistry class. I will make this review as painless as possible. I think you will enjoy it!...

To be continued...