Causes for rear leg weakness in 13 year old dog?

This could be a number of things. Please take him to the vet for a correct diagnosis.
Welcome to Fluther.

Second the trip to Vet.

Could be arthritis. Could be neurological. I third the vet visit.

Could be just old age, 13 is not a spring chicken anymore. A year or so ago I had to put my 13 year old akita down. He was having the same problem. He had simply lost so much muscle mass he just didn’t have the strength left to keep himself up. He couldn’t even keep his tail up over his back anymore.

I would go to the vet, but I wouldn’t let them talk me into a lot of expensive tests that in the end would simply tell me he is getting old. At that age, I just keep them alive until they are not enjoying life anymore, then it is time to let them go.

I also say go to the vet. it could be a number of things, hip dysplasia, pinched nerve, tumor, etc.

I know I’ve heard of dogs getting something where they end up losing all ability in their hind quarters, I’m not sure what it is called or even if that’s what your dog has.

I mean I can give you a bunch of diagnoses but nothings going to make you feel any better until you go to your vet and get a real check up, virtual checkups aren’t that great, one part that makes them not so great is that in a virtual check we are completely missing a vital part of the appointment…the real dog. I hope you find out, to ease your mind. Good luck to you and your dog :)

Yes, take him to the vet asap.
could be anything from arthritis, kidney failure, stroke, spinal tumor, on and on.
Only an examination and possibly some testing will reveal the cause. Do not let your poor dog malinger away when he is either ready to be euthanized or can be treated for the condition and made more comfortable.

Best wishes!

You really need to take him to the vet. He could be in pain. I have had stoic dogs and I have had whimpy dogs. The stoic would have followed me until he died in his steps, no matter how much he hurt. It pains me now, after all these years, to think of baby dogs I have had that died, but taking them to a vet for showing lameness is absolutely needed.

Coloma lists a few things there that it could be, but you need a qualified vet to take a look because of the possibilities are treatable, others need pain management and others you really have to look at the future quality of life for him.

Yeah, a dog’s back legs are basically his “engine room” & at that age require expert diagnosis.