My dog is 16 and has arthritis. A few weeks ago he didn't want to go for walks and seemed to be having more problems with his back legs, not being able to support himself going up a few steps for example. I took him to the vets and she said his arthritis had got worse, prescribed Pardale and I put him on YuMove instead of the other joint supplements he was on. He's been a lot better since, until this evening. Suddenly he fell against DP's legs and couldn't get up. He wasn't struggling to get up, he just sat there for a while. I went into the kitchen, which has a slippery floor, he followed me in and his back legs just went out from under him. He couldn't get up. I picked him up and put him back on the carpet and he seemed better. It hasn't happened again since. What's going on with his legs, does anyone know? My last dog was a German Shepherd cross, which Ddog isn't, and he lost the use of his back legs and had to be pts. He's otherwise very healthy for an old boy.