Growths on the Back of a 9-Year-Old Mixed Breed
Warty growths on older dogs are common and often benign, such as sebaceous adenomas or papillomas. But some tumors can look similar.
A good rule from veterinary oncologists is "see something, do something": any lump the size of a pea (1 cm) or larger that has been there for a month should have a needle aspirate or biopsy. Having one or more checked with a needle test, and photographing all of them, will show whether any change.
See lumps and bumps on dogs and warts on dogs.
This is general information, not a diagnosis. Please follow your own vet's advice.