My 12yr old Yorkshire terrier has been eating and drinking loads these last few weeks, but now he's acting strange and dribbling pee when he's walking

Frequent urination and excessive drinking can be a sign of many things, leezo. You have to remember your lovely little yorkie is a senior citizen now and suffers from many of the same ailments we do when we age.

Kidney failure, Cushing's disease, Diabetes, kidney disease or urinary tract infection are a few and your pet needs a vet visit to determine what it is; could be something easily treatable but you will have to be aware of what it is.

I totally agree, a visit to your vet is in order.