Thyroid testing is done because either hypo or hyper thuroidism is suspected; dogs do not so often get the latter.
The thyroid regulates the dog's metabolic rate; a friend of mine had her Dobe tested 2 years ago and had to have her re-tested and found out that as she had suspected, the dog was hypothuroid.
The sumptoms shown vary but can be: lethargy, problems with the skin (infections, dryness etc) loss of hair, weight gain, dog feeling chilly even when the heating is on, and the biggest problem can be problems with behaviour - changes such as aggression, compulsive behaviour, hyperactivity, fear, phobias or sometimes a fit.It can be hard to diagnose because some dogs do not show many symptoms at all.
Jean Dodds is the expert on thuroid problems; also Alise Shatoff has done some work on "how to analuze your dog's thyroid test" (do a google).
The test for thuroid problems is a blood test and if it is diagnosed, the condition can be treated with a dose of synthetic hormone.
A Six Panel Test must be done and its best to get a copy of the tests because some dogs can be borderline and apparently some vets are not very good at all, or experienced enough, to understand the significance of this ... the dog may be suffering from a thyroid problem but it is not showing up in the test and so the test can seem Normal. Most vets will believe the dog is not hypothuroid and i suspect this is what happened with my friend's Dobe.
There is an article on http://akitarescue.com/aggressi.htm and if you suspect a problem, do read Alise Shatoff's article, it is very good.
Hth
Lindsay
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