Hello, just after a bit of advice and any help you may have. My Guinea pig Elf has recently lost a lot of weight he has dropped 500g over the last couple of months. I have been to the vets twice and they cannot see anything wrong with his feet, teeth, stomach all is healthy. He is not moving as much, and is just generally less active. He is able to eat still and he has been prescribed pain killers daily. Which seem to make a difference to the amount he moves but I am very concerned about his weight loss and what is causing it. Any similar experiences or advice ? Many thanks in advance.