my cat (sage) had a soft lump on his face - one day it burst .. puss and blood came out.
we took him to the vet, who dvised us to leve him there to be put down - as he was riddled with cancer and in extreme pain.
i hope, of course, this is not the case with your dog - but i see no harm in going to see the vet anyway ... at the very least, it will put your mind at ease.
I lost both my cats to cancer. One had a lump on his head but when they inserted a needle, nothing came out. Cancer has always worried me since. My little dog is nearly 12 1/2yrs old. so will definately be checked by the vet.
Well we have been to the vets today but she would not let him near her face so he has given her penicillin and a wash for the abcess and she has to go back in a weeks time if everything is going ok for further investigations when the pain eases. He has found that she has a heart murmur which has never been picked up before but her half sister who I lost 2 1/2yrs ago also had one . This will be a long week but hopefully it will go down and nothing else will be wrong.