My chihuahua has discolored lump on his back...skin was peeling?

my chihuahua is almost 2...dark haired. he has had a bump on his back/shoulder...but i thought it was from his shots a couple months ago. i was petting him tonight and moved the fur back and noticed it was a greyish spot...about the size of a walnut and the skin was starting to peel off. im taking him to the vet tomorrow but does anyone know what this might be? could a skin allergy be concentrated to one spot??? help please!

My chihuahua has discolored lump on his back...skin was peeling?
I've heard about injections causing problems. Search it online.





Also I heard about different pet foods causing cancer...and lumps. I don't know which brand is best, but you could search that out also. There are so many chemicals and dyes in pet foods.
Reply:ooooooo yeah my dog had that too well still does take em to the vet immediately so the disease wont spread anymore or you'll have to spend alot of money!!!!!! it's caused usually by other dogs urine or # 2 !!! good luck
Reply:take him to the vet could be cancer this has happened to my friends dog dont fool around with it get it checked out dont mean to scare you but lumps need to be looked at
Reply:he probably has mange
Reply:It could be allergies, but it maybe some sort of non malignant skin cancer. I just had my dog of 15 years into the vet. She had 4 removed. One by her elbow joint one on her neck, which had stitches. She also had 3 small ones which the vet just burned with an laser. You are very smart to take her to an vet, sometimes they do a skin scrape to detect how to precede. GOD BLESS YOU! sus04mc@yahoo.com