Iodine, goiter, and animals

[Mokele]

In Animal Physiology class today, we were discussing thyroxine, iodine, and how lack of iodine causes goiter, and how goiter used to be common in some areas until we supplemented salt.

 

But that got me thinking: Why don't we hear of animals getting goiter, or suffering from iodine deficiency? I mean, we're eating more or less the same things (plants and other animals), so if the local human food doesn't contain enough iodine (due to soil deficiency or whatever) why wouldn't we see the same in native wildlife?

 

Is it some aspect of biology that's peculiar to our brand of neotenic apes?

Or is it something to do with diet, like the parts of the animal we eat, or how we grow our plants?

 

In short, what makes us different in this respect? Or are we just noticing because it's humans, and it truly does occur in animals in the same areas?

 

Thoughts?

 

Mokele

[coquina]

At least, cats, rats, dogs, cows, pigs and sheep can. I did a quick search using hypothyroid with feline canine, bovine, porcine, and murine and found vet links to all of those problems.

 

Of course, they are all domesticated animals or lab animals, so humans have a hand in what they eat, I don't know whether that might affect them or not.

 

Another search on rodent thyroid disease turned up this article:

http://ehp.niehs.nih.gov/members/2003/6637/6637.html

 

I scanned it but didn't really read it for evaluation - the title is interesting:

Thyroid Toxicants: Assessing Reproductive Health Effects

 

What the heck is a thyroid toxicant?

Found this:

http://www.clinicaltrials.gov/ct/gui/show/NCT00043238?order=2

Mohawk Culture, Behavior, Toxicant Exposure and Health

 

The proposed study follows-up 220 Mohawk adolescents aged 17-21 years, who participated in a previous study when they were 10-16 years old. All adolescents are members of the Mohawk Nation at Akwesasne which is located on the St. Lawrence River and is adjacent to hazardous waste sites where PCBs have contaminated the local ecology. The investigation examines the interrelationship between Mohawk cultural identity, traditional Mohawk customs, behaviors related to toxicant exposure and current toxicant burden. Serum level of PCBs will be assessed by congener specific analysis. The study will determine the relationship of congeners and their hydroxylated metabolites to thyroid function (levels of triiodothyronine, free triiodothyronine, thyroxine, free thyroxine, thyrotropin and anti-thyroid antibodies), and 2) psychosocial outcomes including school behavior and performance, hyperactivity, and adaptation to the community.

 

That was a real quick and dirty look - but it does lead one to wonder whether there is an increased incidence of thyroid disease in humans and animals due to exposure to various toxicants.

 

Gotta go to work - later...