chronic ear infection and thyroid

Question
My labrador is a 15 year old female who has always had a chronic ear infection mostly consisting of yeast & bacteria. I clean them on a regular basis with ear flush and medicate them when they flare up. She also has a hx of epilepsy, her seizures are controlled with phenobarbitol (45mg bid). Despite these problems she appears to be in great shape. Recently she had senior blood testing and everything looked fine except the screening for her thyroid. It was detected that further testing should be done ($80) to determine if she needs a suppliment or other action should be taken. The vet mentioned that it is especially important to pursue the testing in a dog with epilepsy, but I can't imagine spending the money if it's really not that critical to her health or longevity. I'm also not sure if ongoing use of synotic or other ear meds may also show thyroid imbalances. Please help if you have insight-thanks a million!  

Answer
Some dogs with seizure activity have low thyroid hormone levels and supplementation can prevent them.  If testing indicated that this may be the case, then you can either do further testing to confirm the diagnosis or you can treat with thyroid hormone tablets (which are not real expensive).