T4 Levels

[sarabz]

Bella's T4 approximately halved since last year. Is this something I should be concerned with? Vet wants her to be on thyroxine.

[Guest budsmom]

Did they send the test to Michigan State? They do the gold standard in thyroid testing there. I wouldn't do anything until getting results from MI, and only then if she is symptomatic. MI State sends along an interpretation of the results based on breed, they are well aware of greyhound quirks.

[Guest LindsaySF]

Send out a full panel (T4, free T4, TSH). T4 is normally lower in Greyhounds compared to other breeds, and it can fluctuate a great deal. Too many vets misdiagnose hypothyroidism in Greyhounds.

[greysmom]

Is there any other reason he believes Bella is hypothyroid?? Any symptoms at all? Lots of shedding or losing hair in odd places, a sudden poor coat quality, brittle toenails, a sudden increase in anxiety, a sudden lack of energy? Thyroid can fluctuate quite dramatically at times and still be completely normal. Even something like antibiotics can cause it to have an odd reading. It can be suppressed or increased by supplements or drugs. Even the time of day of the blood draw and the relationship to eating can make a difference.

 

Even then, if you repeat the test and it's low, or send it out and it's "low," in the absence of other symptoms I would probably not do any treatment. One of my boys had a reading of 0.2 and that was entirely normal for him.