Finally had my Spring vet check and all results look good.
Timber has made a pretty amazing recovery under the circumstances. She still has some hind leg quivering. Not sure if that is a result of the disease or weakness from muscle loss?
She has been on the recovery SA Extra Strength for a few months now and I think it has helped. She does not limp but still has some muscle loss in her hind legs. We are to continue with regular exercise but she looks great, her coat has grown in nicely and, with the exception of the quivery legs, is back to her old self again.
Interestingly, I received a two page letter from the emergency clinic (where she was first misdiagnosed) about heartworm, anaplasmosis, lyme and ehlrichiosis. It was fairly detailed and talked about the symptoms and treatment. It also said that early detection it important for a full recovery. A little too late for us but I am glad that this information was sent out to their clients and hope that it helps to save more dogs. It said they are seeing an increase in tick disease so hopefully Timber's case helped to inspire this mailing (although no one mentioned this to me) but I like to think it is true.
I guess this is a final and happy ending to this very long thread that started with so much uncertainty.
Thank you again for everyone's support here!