I think you'll need to leave it more like a week for the Metacam to wear off, if yours is anything like our two.

I spoke to a vet friend last night. There is a cheaper (because generic) alternative to Metacam - the ingredient is called Carprofen (?sp), it's usually sold as Dimidril (?sp - that's what I think the guy said)
Metacam doesn't come out of patent for another couple of years.

My friend confirmed that Ibuprofen is toxic to dogs, and paracetamol is also not a good idea. For short term pain relief, use a suitably scaled down dose of soluble aspirin.
(He also said don't give aspirin to cats under any circumstances, if anyone needs the info!)

Different species, different metabolisms!

Good luck