Here is an article about this: http://www.marvistavet.com/html/body_ca ... lomas.html
We have had FAST results by using the antibiotic "azithromycin" for 10 days. You may need a prescription from a vet, it ran about $70, but is cheaper than surgery - which in our experience they have grown back every time after surgery. With the antibiotic they were gone within 2 weeks and never came back nor did any other dog get them.
They can be very contagious to other dogs.