Some vets prescribe augmentin for infections but you would have to check with your vet for a dosage.
If the wound is oozing/draining, it sounds like you need vet intervention anyway. The wound may need to be flushed and you may need more care than you can provide at home.
Augmentin is Clavamox...you should be familiar with that in vet medicine. 500mg is on the higher end of the dose but you can use it for a 50lb dog. Use 1 tablets every 12 hours for 7-10days...hopefully you kind get to a vet if needed. Make sure you give medication with food.