So there is a rat at work( i work at a pet store) and iv been watching him for the last couple of weeks and at the begining he just looked like he had a little bit of a balance problem or some sort of neurological problem, but as time has went on iv payed more attention, an he has a head tilt, now a massive one, but its there, he walks favoring towards that direction. He cant stand on his hind legs without holding something or he falls over. I have seen this with mice n it has to do with some virus in the ear but its very quick and they fall apart very quickly whereas he isnt. I looked in his ears n there doesnt seem to be anything that looks abnormal, so if it is a ear problem its deep in the inner ear? Any suggestions?