Hyper thyroid!!??

Myriam Desrosiers

Hi! I'm a little concern here about Aragon's Free T4... last test he was on the lower edge of the normal range. He had a test redone on October 5 and he would be Hyper Thyroid... Vet could'nt tell me much about it... Once again i'm very worry about his condition. I'm not giving him any medication. Iused to give him T4 hormone last winter, but i stopped in december. He is being himself since diet was balanced, special Thanks to Carol Broyles, doing some exercise and not lame... Should i stop the iodine in his diet?  The test made was T4 by RIA. Result 3.2 ug/DL. and the reference range is 0.9 - 2.8 ug/DL.
MyriamD, Qc, Canada



Trisha DePietro

Hi Myriam.  Was there a reason you retested the free T4 level on Aragon? Were there specific symptoms?

I reviewed your case history...Did you happen to retest his insulin level?  It was high in May 2021. Did you do any changes in management for the insulin level? 

He sounds pretty happy with a balanced diet, some exercise and not lame....

I'm not sure I would stop the iodine- perhaps decrease it? But I would ask your diet balancer- Carol Broyles about reducing the iodine...not sure if that would hurt or help your freeT4- I am sure there is another primary responder/moderator that will know the answer to that one :)  
Trisha DePietro
Aug 2018
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Nancy C

Hi Miriam

Thyroid and other hormonal testing can give back wonky tests from biotin in the diet.  It is not a health issue or real changes in thyroid levels caused by the biotin but described as an "artifact"

This is the original thread announcing the human study and Dr Kellon's comments


The link to Guidance from AACC in Dr Kellon's link  describes the half life of biotin in humans as follows:

"Low concentrations of biotin are cleared quickly from the circulation of healthy individuals, with an elimination half-life of approximately 2 hours (30), whereas experiments with high doses indicate a half-life up to 18.8 hours (11).

Dr Kellon please correct my take that withholding for 24 hours would clear the system. I also wonder about withholding all minerals for a day if the biotin is already mixed in the supplement and that is the only option.You can also buy and add biotin separately.

I would not stop or lower the iodine. It is really important for thyroid health.

Nancy C in NH
ECIR Moderator 2003
ECIR Group Inc. President/Treasurer  2020-2021

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Myriam Desrosiers

Aragon was always on the low with his thyroid, and i understood, maybe i’m wrong, that it was an effect of IR than a cause. Since he was always on the low range. I was wandering if i still needed to give him T4 supplement… i guess not! 

I live very far from a city, having a vet visiting is something difficult. I’m not feeding him Any supplément of biotin… could there be an other reason  why his thyroid is so high!!!?? 

For his insulin management, he does exercise, balanced diet, i weight his hay and put it in a net, so he eats slowly… and hay is at 8.6 sugar + starch. Please let me know if there is anything else i can do for help manage his insuline level… thank you!


MyriamD, Qc, Canada



Eleanor Kellon, VMD


That number is really in a grey zone. I wouldn't worry about it unless you start to see signs - nervousness, high heart rate, weight loss.
Eleanor in PA

EC Owner 2001