Thank you for your reply.
In Yorkies, especially this young, I really feel that two tests are necessary.
Unfortunately, it sounds like you have done a lot of testing already, without any answers. This is always frustrating.
But, I think a full blood panel is needed for your Yorkie. This breed very typically will have liver shunting especially when they are young. It can lead to lack of appetite, at times low blood sugar, and in general can cause these young Yorkies to just not feel very well.
In the blood you would be looking for changes in glucose, liver enzymes like ALP, increased bilirubin values. They might want to do a special test called a bile acids test. This tests the overall function of the liver. And is a good place to start.
Liver shunts can be difficult to determine. AND because of this I often also recommend an ultrasound of the abdomen.
This is important for TWO reasons:
1. shunts may not be seen until an ultrasound is completed
2. eventhough an xray has been taken, some foreign bodies do not show up on an xray. Cotton, smaller pieces of rubber, and many other foreign bodies are very hard to see on xray. Bone
, metal, and harder or more dense objects show up very well.
So, I do think that the bloodwork, with likely bile acids, and lastly the ultrasound are the way to go. If you can do all of these things that would be even better.
Cost can be an issue, but this is a young dog and might have a very long life ahead of it once treated and diagnosed.
This isn't a diagnosis I offer to you, but just what would be considered the next standard tests in order to find out what is wrong. I don't benefit from recommending these tests in any way as an outside consult on this case. However, your puppy may benefit from them, and that is my goal!
Does that make sense?