18 y.o. cat

Question
Our "senior" cat of 18 yrs. is and always has been an outdoor cat. He was found hiding in our children's pay house one Spring when we went out to clean it up for play. He was very nervous and skittish but because of my husband's patience, over a period of 3-4 mo., we were able to pet him and approach him slowly and on his level. We named him "Allie" for alley cat. He has become our favorite cat and we have tried take very good care of him. He is now very gentle and even trusts us to rub his belly. He has been acting strangely today. He likes to hunt and capture and kill small mice, a bird, etc., and as a trophy lay it on the mat at the back door. Well, today, he was lying on the mat. He never does this. I thought he just wanted some attention and I sat with him and rubbed him. Each time he seemed to make a strange sound as if I were hurting him. I tried to be very gentle. Then he tried to walk to his water and food bowl but appeared to be disoriented and his left back leg was unable to hold him up and he fell several times. He seemed to be surprised when this happened. I sat the feeder next to him and he ate and drank while lying down. He can still move but only a step or two. I want to point out that for a while now he has walked slowly and kind of humped over. We attributed it to his arthritis. He takes medication for his arthritis joints and for the pain. I put it in his food and he eats it without rejecting it. My question is: do you think he has a broken hip or perhaps it's inner ear problems. He has has trouble with his ears in the last year due to ear mites and the vet treated him with cleaning and medication. There have been times when he scratched so hard he was prescribed penicillin due to an infection. Do you think it is his ears or his hip? I am very concerned about him and even though he is old, he usually appears to get around as well as can be expected. We have a workshop/craft shop behind the house and he sleeps in the rocking chair when it is cold outside but loves to be outdoors if at all possible. What can we do for him before we can get him to a vet on Monday? He is so pitiful and we love him so much. He has literally grown up with my children.

Answer
Hi Barbara.  Sorry to hear he's having such trouble.  It seems like the worst things always wait to happen until the weekend!  Is there any urgent care center in your area?  Problems with the back legs could be caused by arthritis.  Trouble with balance can be caused by serious inner ear infections.  But there is also a possibility he's become diabetic.  It's surprisingly common - I have three cats on insulin shots!  When the blood sugar is very high, nerve damage can occur and cause weakness in the hind legs and fatigue when walking.  It's pretty standard to have a severely diabetic cat walk a couple of steps and then collapse.  There's also the potential he's got a blood clot lodged in an artery that's limiting the oxygen that's getting to his legs.  The cat will have lack of coordination in his back legs, or they will drag.  Sometimes you can feel that the affected legs are cold to the touch, or the paw pads are gray or pale in color.  I'm not sure any of these would explain his sensitivity to touch, however.  He may have a growth in the abdomen that's causing pressure and pain, or perhaps an inflamed liver, pancreas, kidneys or intestines.  

Unfortunately, I don't know of anything you could do to keep him comfortable until he sees the vet.  I would recommend to try to keep him in the workshop, though, until he's seen, as he's too slow to keep himself out of harm's way right now.  Perhaps offer him a heating pad to sleep on if it suits him.  I hope all goes well and he's back to himself soon!