Like viral papillomas, these are technically tumors, though both are benign. “I’ve seen hundreds of cases of benign histiocytomas,” Miller says. “There are some larger breeds where these tumors can be malignant, but I’ve never seen one.” If you have a larger-breed dog, he adds, you might be more inclined to bring your dog in for an exam when you spot a histiocytoma.
They usually manifest as small, red, eraser-like bumps, often located on a dog’s head, neck, trunk, ears, and limbs..
They’re more common in younger dogs and usually go away within 1-3 months, though Miller says they can and probably should be surgically removed if they become painful, start bleeding, or triple in size. Also, “if your dog is older, it probably isn’t a histiocytoma, but rather something more serious, so definitely have your dog checked out in that case,” he adds.