Steroid paralysis???

Charles,,, the dog last yr was not snake bit but for some unknown reason became paralyzed over night,,,now granted he was 15 yrs old and he had lived a full life and a hard one being as he was a ruff dog and had been cut up from can to cant... This male is only 6 ,, so I took him to a vet and he is doing better but to her diagnosis,,, we cant figure out if the snake bite last week was the cause of it or what... Just trying to find out from different folks if they ever had experience with the same symptoms.. he is up on his feet now and looks to be overcoming it,,,, I wont hunt him for another couple of weeks to give it time and then it will tell the tale ... thanks for the info...