Our 13yo dog had a Tardac injection last week to treat his anal adenomas - the vet did warn us that he might seem a bit hungrier than usual but not to feed him extra. We have split his food into two smaller meals in an attempt to make him feel like he's getting enough but for some reason he has now gone off his (previously perfectly acceptable) food and is now on the mooch for anything else he can find.
He's tipped over the wheelie bin (he is a BIG dog) three times today alone. He is raiding the compost bins and stealing the poor cats food - he can open doors so its hard to keep him away if he is determined. He's just been caught trying to bury a packet of mouldy pitta bread 
and he is currently sat outside chewing one of the horses toenail clippings [blurg]!
Is this normal? What can we do, other than make extra efforts to keep him away from all sources of skankable food?