Hi everyone. Just found this forum. I have a 5 month-old chihuahua...white, long-coat......and it has lost most of its hair on the underside of the neck, belly, and knees. It looks horrible. I've contacted the breeder and she said long coats lose their puppy hair....but I've seen other chi pups and this looks freakish. Had it at a vet last week and he said the dog was underweight and this may be contributing to it. We now have her on a a healthy (expensive!) vet-food diet but have seen no change in the hair loss. Any idea why she would lose so much hair, and only on the underside? I asked the vet about a thyroid problem and he said it was doubtful in a dog this young. The skin looks fine and she doesn't scratch at it. Any leads/advice appreciated! Thanks. PLEASE SEE PIC BELOW!