Nothing wrong in taking a pet turkey to the vet Minbn, we take our pet cockerel and any other chickens we don't want to simply despatch just to save time and money. It may not be bumble foot, perhaps it could be a bad sprain and the abscess is co-incidental. You could try applying arnica gel on his foot over a period of a week.
We treat bumble foot in chickens by thoroughly washing the foot, very carefully removing the scab on the pad with a scalpel and squeezing out the yellow puss. We then pack the wound with tea tree cream and bandage it up with lint and micropore tape. It's very difficult because if you nick a vein and they start bleeding you can't see to get all the puss out. it can take half an hour, so your pet needs to be very relaxed about it. the wound usually heals over by the time the micropore tape falls apart, but worth checking obviously.
The 'puss' with chickens sets in a solid lump, so giving them antibiotics won't see the lump reduce immediately and perhaps Turkeys are the same? Poor chap -hope he's OK.