Pet Gold Fish - Urgent

Question
My pet Goldfish has just suddenly seemed to loose its balance and is slowlyleaning from the3 vertical to being horizontal. If we hold him up right he seems to recover life and swim for about 30 second, but them tips over again.
He is around 13 years old and I think called a fantail which is all one coulor of orange. Please can you help us to do something to save him.

Many thanks
Becky

Answer
Becky...
how big is your goldfish?  What size tank is he in?  What water maintenance do you do for him?  It sounds to me like a swimbladder issue with this fish...many fish never recover...you can try doing 50% water changes over the next every other day and see if it gets better.  I'm sorry for the bad news.