Two of my dogs are hypothyroid. It's fairly common in all dogs, extraordinarily common in sled dogs. Preacher has been on thyroid meds for years. Earle just started meds a few months ago. They each take .9mg twice a day.

The potential list of symptoms for hypothyroidism fills several pages in the Merck Vet manual. Preacher had all the classics--low energy, poor coat, gaining weight, unable to cope with the cold, grumpy. Earle's were a little more complicated, but the weight gain was what led to the testing.

If it really is the thyroid that is causing Maggie's troubles, you will seen an improvement very quickly. Within three days, Earle was acting more like himself. Be careful when she starts feeling better. One of the common complications of thyroid medications is a blown cruciate ligament. The dog starts feeling better, starts to run and play more, but is still too heavy and their knees can't take it!

Thyroid conditions do not go away. The meds will not fix the problem, they just deal with the symptoms. However, it will not affect Maggie's lifespan.