we have a two year old Airedale. his whole life he's been unstoppable a super energetic dog!over the last two weeks he's changed dramatically, sleeps the majority of the time, seems to limp when he walks ( like he aches rather than injured)and has little interest in anything except eating... oddly. trip to the vets - diagnosed stomach upset, antibiotics and bland diet for a week, no injury- all good stuff but very little improvement. before we get into expensive tests and xrays...anybody any ideas?