If you think his hip is bothering him, take him to the vet. They have better pain killers than are available over the counter. If his hip is bothering him at such a young age, it must be severe. You may want to look at surgery.
If you fall to the temptation of OTC pain killers, avoid the modern ones, nothing but buffered aspirin, 5 mg per pound of dog every 8 hours.
Keep his weight down to ease joint problems, see
http://www.puppychow.com/products/po...condition.aspx