I have a female doberman that is 8 1/2, she will be 9 in september. She has always been in good health but in the last week or so she has lost a ton of weight. She is down to 46.5lbs from a little over 60 normal. I took her to the vet and there are no heart murmurs, no adventitious lung sounds, no lumps in her belly, and her teeth look great. The vet couldnt even believe she is as old as she is. She is still hyper and energetic like always. She just doesnt seem to have the appetite anymore. Anyone have any suggestions as to what I can use to fatten her back up?