Your picture came through. Romeo has a major mass that is ulcerated and looks to be infected. He needs to see a vet right away for proper wound management, pain medication and antibiotics. This is a massive mass that cannot be managed at home without the help of your local vet. Once the infection is controlled then it can be discussed whether this mass can be debulked or not. If it cannot then your vet may recommend amputation of the leg. I am sorry your pet has such a massive tumor and I hope everything works out ok for your pet Romeo. Best wishes and take care.