| It is very very rare for a competent vet to just say that they don't know what it wrong with the dog.
There are tests for nearly every ailment under the sun that they can do to determine the cause, some take a long time for results to come back, others you can find out in a day or two.
My guess is that either you have been told of certain tests and they were too costly or that particular vet does not know about the tests or does not want to do them for some reason.
One thing that I know can be a problem with Maltese is slipping patellas, these can be very painful and cause them to either walk strangely or not want to walk at all causing muscle wastage.
The patella is basically the knee-cap in their hind legs, sometimes the muscle holding the bone in place is weak, causing the plates of bone to slip out of place. It is a genetic disorder and any good breeder will have a dog spayed/neutered immediately after discovering they have this problem.
Another common problem which my mothers poodle has is cruchet ligament damage. This unfortunately isn't something that is easily fixed and the best coarse of action is simply to rest the dog as much as possible until the injury has healed.
Her dog walks with a severe limp and often holds his leg up as you have described, he also has significant muscle loss in his hind legs.
Some dogs get over ligament damage, others don't. In her case it is a recurring problem so he is fairly restricted with his exercise these days.
So as others have said I would be getting a second opinion. |