Thanks for the response Dr Redford, I took him back to the vet and they gave him antibiotics and anti-inflammatory they have a long list of expensive tests that they want to do, they checked and his anti coag has a little high but otherwise they felt it wasn't that bad, they checked for heart worms and next week we are taking him back for some more blood tests, I tried ice packs he is a huge baby and won't lay still long enough, the medicine seems to be helping again the swelling that was getting worse has gone down some and the discoloration is getting better, they are still scratching their heads again over this, they said the bruised appearance could be from the swelling (causing small blood vessels to burst?) I was unsure about that response? the bruising is what concerns me, both times it appeared the same way, dark bruising then severe swelling within hours? could poison ivy sumac or oak do that?
Any chance it is a bleeding disorder? Check the gums for any bruising and seek a vets office if you see any.
Normally an infection would not cause bruising and I feel it was a coincidence that it went away with the anitbiotics. In the meantime, good old iice and pressure always helps.