Just got in from work and one of my cats (16 yr old male) is limping on his back leg - seems to be his hip causing him pain. He's fine in himself and eating but obviously a bit uncomfortable. I will take him to the vets in the morning if he's no better but we have some liquid loxicom left from the last time we tried it for his stiff back legs - would it help to give him a dose now do you think? The bottle has probably been open between 6-12 months.