Thyrol-L and Thyroid tests

[targetsmom]

Several people have suggested that we put our 2 year old filly on Thyrol-L because of fat deposits in her neck (heavy crest). Our vet has been reluctant to recommend Thyrol-L based on her test results:

Free T4 3.15 ng/dl (apparently high)

Total T4 2.32 ug/dl (apparently normal)

Total T3 0.52 ng/ml (apparently normal)

For those of you who use Thyrol-L, how do these test results compare with what you saw? I am planning to switch her over to a lower calorie grain and cut back her feed a bit. But other than the fat on her neck and near her udder, I don't think she is fat. She does not have a depression over her topline nor fat around her tailhead. And the heavy neck has not seemed to hurt her too much in the the show ring. This is the only photo I seem to be able to post that isn't tiny! Any suggestions???

 

[Nathan Luszcz]

Thyrol-L is probably the single most mis- and over-used MEDICAL suppliment out there. It is unbelievably rare to have a thyriod problem in a horse that honestly is a thyriod problem. There are several diseases that directly effect the thyriod gland (Cushings being one of them). If your horse does have a thyriod problem it is highly suggested that you try to find out WHY there is a problem, and not just treat the symptoms. For many things just treating the symptoms is great and solves the problem, and thyriodism APEARS to be one of those. But let me explain how and why T3, 4, and Thyrol-L work, which will help explain why treating the problem is a serious problem in and of itself.

The thyroid gland (like most endocrine glands) depends on feedback to tell it what to do. It constantly moniters the blood levels of circulating thyriod hormone, upping production if the levels are low, and lowering production if they are high. Its a constant system that is always adjusting. If you add Thyrol-L, which acts (and looks) like the thyriod hormones, the thyriod gland will cut production, thinking there is a oversupply. Short term this is okay and the body will do fine when you take them off the suppliment. But if you use it long term with a higher dose than the body normally makes for itself, the thyriod gland atrophies and shrivles up, ceasing any and all function. That, obviously, is bad.

Last I read (two years ago), Thyrol-L was recommended for a two to three month period, after which it should be discontinued. So please reconsider using Thyrol-L as a metabolism booster.

As an interesting side note, both progesterone and testosterone work the same way. If you suppliment a stallion (or a human) with testosterone long term, their testicles will shrink, and sperm function and development will stop, perminently if you use it long enough.

Oddly enough, the progestin suppliment Regumate is NOT recignized by the body as natural progesterone, meaning it has no negative feedback effects.

But if you use Regumate on a stallion, the same thing as with testosterone will happen.

 

[Mona]

Here are the results of 2 of my mares results from this year. One was in April, the other just this month.

 

[Fred]

`Mary I have two horses on Levoxine [ThyroL]. Both NEED to be on it. I do not give it just because a horse has a heavy crest. Thyroid can fluctuate when you are working the horse thats why even if the horse is on it the horse should be tested. Diet can also help [no sunflower seeds]. Linda B

 

[Mona]

`Mary I have two horses on Levoxine [ThyroL]. Both NEED to be on it. I do not give it just because a horse has a heavy crest. Thyroid can fluctuate when you are working the horse thats why even if the horse is on it the horse should be tested. Diet can also help [no sunflower seeds]. Linda B

Fred, are you saying BOSS can cause these low thyroid levels?

 

[targetsmom]

Thank you all. These comments are very helpful, especially the actual test results. I already stopped the sunflower seeds!!! Those seemed to have an almost instant effect on laying down fat. I will try the lower calorie grain and see what happens. This filly is quite a challenge.

Mary

 

[Fred]

No Mona, Mary knows about sunflower seeds giving extra fat in places [crest and udder] where they don't need it. It has nothing to do with thyroid. Linda

 

[Mona]

No Mona, Mary knows about sunflower seeds giving extra fat in places [crest and udder] where they don't need it. It has nothing to do with thyroid. Linda

OK, thanks for clarifying. When I read that, I thought maybe that was the culprit for my mares thyroid problems!!

 

[HGFarm]

I also have a mare on Thyroid L as of 6 weeks ago when she would not resettle and her tests are low. She will be tested again in 2 weeks to see how she is doing. She is heavy, which made the vet suspicious but I would NEVER put a horse on this for 'weight management'!!!!