cant walk the dog! help!**

I am getting ready to go on vacation. 1st time in years. I have never been this big b4. I am taking the dog with me. normally at home my sister walks the dog. But during vacation she is going to stay with my bro. I HAVE to take the dog with me. I will be staying in hotels, so it going to be up to me to walk the dog. The problem is I cant stand or walk for more than 5 mins with out severe back pain. Any ideas on what I can do? Please response ASAP I am really worried.