Topics

thyroid l


LJ Friedman
 

I remember reading about so many horses were on thyroid L for weight loss. And we know that’s not indicated. Am I also correct that thyroid L  is never indicated? For example if a horse shows low T4 from Cornell would that prompt us to use tyroid L ?
Thought I remembered reading posts that horses are never low thyroid one in 1 billion one in 1 trillion or something like that
 this isnt for jesse or majestic  just general knowledge 
thanks
--
LJ Friedman  Nov 2014 Vista,   Northern  San Diego, CA

Jesse and majestic ‘s Case History 
Jesse's Photos

 


NANCY BOTTE
 

My vet had us start our Mini/Shetland on 1/2 tsp. of thyroid L. She believes it will increase his metabolism. Maybe lose a few lbs even though she feels he's not overweight....I'm kind of confused why he's on it....


--
Nancy B
NH
2020

https://ecir.groups.io/g/CaseHistory/files/Nancy%20and%20Twister 


Sherry Morse
 

LJ,

You are confusing 2 issues.  Thyro-L can help with weight loss, it does not help to decrease insulin.  From a message Dr. Kellon wrote in 2018 when you asked about this:

The Equine Endocrinology Group (led by Dr. Frank) only recommends levothyroxine (Thyro-L) to accelerate weight loss, not to lower insulin:

https://sites.tufts.edu/equineendogroup/files/2016/11/2016-11-2-EMS-EEG-Final.pdf





Sherry Morse
 

Hi Nancy,

Twister is IMO a bit overweight so it could help him, but it should be used in conjunction with diet changes as well. 




Nancy & Vinnie & Summer
 

This is great info. So if T4 shows low in my mare's bloodwork, would that also be a reason to use it?

Can someone pont me to the article/study that shows insulin sensitivity not increased by thyro l as it was prescribed to my horse for this reason and I would like to share it with my vet.

Thanks Nan
--
Nancy and Vinnie and Summer
Oakley, Ca
Joined Nov 2018
https://ecir.groups.io/g/CaseHistory/files/Nancy%20and%20Vinnie 
https://ecir.groups.io/g/CaseHistory/album?id=245855

Summer
https://ecir.groups.io/g/CaseHistory/files/Nancy%20and%20Vinnie/Summer 
https://ecir.groups.io/g/CaseHistory/album?id=249104


NANCY BOTTE
 

Hi Sherry - 
I am working on taking some pounds off Twister with exercise and doling
out less hay to my  3 when out.  Also soaking all hay till I can get a
handle on this. As with many things, especially this - its a work
in progress!
Thanks for your input!




--
Nancy B
NH
2020

https://ecir.groups.io/g/CaseHistory/files/Nancy%20and%20Twister 


Sherry Morse
 


Nancy & Vinnie & Summer
 


hmfox77@...
 

Hi Sherry,
I hope it's okay to jump in this conversation... but I'm confused by the study you posted.  To me it sounds as if this study concludes that Thyro-L does increase insulin sensitivity?  I'm just trying to clear things up for myself because my vet prescribed it to my IR horse and after I joined this group I thought I understood that it did not do anything for insulin.  I've been weaning him off of it but after reading this study now I'm wondering if I should keep him on it.
Thanks for any clarification you can give!

--
Heather F
Minnesota
June 2020

Case History
Photo Album


Kim Rice
 

Hi Sherry and Scutch,


I tried to get through the Study but am not sure where Thyro-L comes in.  Could you help me to zero in on that part?

Thanks,
--
Kim R, Lafayette, CA  2019
https://ecir.groups.io/g/CaseHistory/files/Kim%20and%20Shomee


Sherry Morse
 

Hi Kim,

8.1 Levothyroxine. That's the chemical in Thyro-L. 

8.1.4 Conclusions Levothyroxine administration has been associated with weight loss and increased insulin sensitivity in horses, but studies are now required to evaluate this treatment in obese insulin-resistant horses with EMS.11,248,249,259  


11. Frank N, Elliott SB, Boston RC. Effects of long-term oral administration of levothyroxine sodium on glucose dynamics in healthy adult horses. Am J Vet Res 2008;69:76- 81. 
Study group was 6 healthy mares.
Conclusions and clinical relevance: Long-term administration of L-T(4) was associated with weight loss and increased SI in adult euthyroid horses, although other factors may have confounded results. Levothyroxine sodium may be useful for the treatment of obesity and insulin resistance in horses, but further studies are required.

248. Sommardahl CS, Frank N, Elliott SB, et al. Effects of oral administration of levothyroxine sodium on serum concentrations of thyroid gland hormones and responses to injections of thyrotropin-releasing hormone in healthy adult mares. Am J Vet Res 2005;66:1025-1031. 
Conclusions and clinical relevance: Administration of levothyroxine sodium increased serum tT4 concentrations and blunted responses toTRH injection in healthy euthyroid horses. (NOTE: Nothing in this study had anything to do with insulin)

249. Frank N, Sommardahl CS, Eiler H, et al. Effects of oral administration of levothyroxine sodium on concentrations of plasma lipids, concentration and composition of very-low-density lipoproteins, and glucose dynamics in healthy adult mares. Am J Vet Res 2005;66:1032-1038. 
Results:...Insulin sensitivity significantly increased (> 2-fold) in treated horses, but glucose effectiveness and net insulin response were not affected. 
Conclusions and clinical relevance: Administration of L-T4 decreases blood lipid concentrations, improves insulin sensitivity, and increases insulin disposal in horses. Levothyroxine sodium may have potential as a treatment for horses with reduced insulin sensitivity.

259. Frank N, Buchanan BR, Elliott SB. Effects of long-term oral administration of levothyroxine sodium on serum thyroid hormone concentrations, clinicopathologic variables, and echocardiographic measurements in healthy adult horses. Am J Vet Res 2008;69:68-75. 
Conclusions and clinical relevance: In horses, long-term oral administration of 48 mg of L-T(4)/d significantly increased serum tT(4) concentrations and did not appear to adversely affect health. (NOTE: Nothing in this study had anything to do with insulin)




Sherry Morse
 

Hi Heather,

As per this message from Dr. Kellon (https://ecir.groups.io/g/main/message/234632)
" Levothyroxine induces weight loss and reduces neck circumference in horses with EMS when animals are kept on a weight maintenance diet, but does not influence glucose dynamics or insulin sensitivity. " 

Read pages 74 to 84.




LJ Friedman
 

Knowing that thyroid L shuts down the thyroid and prevent it from working, is there any ever way to stop the thyroid l  after years on it and get the thyroid back to work?
--
LJ Friedman  Nov 2014 Vista,   Northern  San Diego, CA

Jesse and majestic ‘s Case History 
Jesse's Photos

 


Nancy C
 

If you are removing thyrol -l you need to make sure you have a balanced diet and wean very,very slowly.

This message https://ecir.groups.io/g/main/message/209067

...talks about weaning very slowly on high doses.  I assume long-term is in the category.

Sherry has given a lot of good back up info.  Here's a bit more

https://ecir.groups.io/g/main/message/229084

Adequate Iodine and Selenium are particularly important.  Here are a few messages

https://ecir.groups.io/g/main/search?d=0&ev=false&q=posterid%3A58231+%2Bthyroid+%2Bselenium+%2Biodine&startdate=08%2F06%2F2020&enddate=08%2F06%2F2020


--
Nancy C in NH
ECIR Moderator 2003
ECIR Group Inc. President/Treasurer  2019-2020
Join us at the 2021 NO Laminitis! Conference, August 12-15, Harrisburg, PA


Eleanor Kellon, VMD
 

All of these studies were done in normal horses, not horses with EMS. The "other factors" mentioned include diet and weight loss.

Dr. Chameroy's thesis work on thyroid supplementation in EMS horses found it does not influence insulin sensitivity:

https://trace.tennessee.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=2019&context=utk_graddiss
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001