We have an 8 or 9 year old border collie. recently he was diagnosed as having lyme disease. He is taking tetracycaline and in the last week or so, he has started eating rocks and gravel and throwing up. We changed his dog food because he started refusing the old food. He is also losing hair along his front underarms and along each side. that could be from crawling under things though. HELP!!!!!!!!!!!!!