A Flap of Skin Hanging Off a Lab's Back

We weren't able to see the photos with your question, but a soft flap of skin that hangs off the body is very often a skin tag. Skin tags are common in middle-aged and older dogs, especially larger breeds, and they're harmless in most cases.

Please don't pluck, cut or tie it off. A skin tag has its own small blood supply, which is why it fills with blood and turns red when you squeeze it, and removing it at home can cause bleeding and infection. If it isn't bothering him, it can usually be left alone.

It's worth showing your vet at his next visit rather than as an emergency. Go sooner if it grows quickly, bleeds, changes color, becomes hard or ulcerated, or he keeps licking or catching it. A vet can usually tell skin tags from other growths with a quick look, and if there's doubt, a needle sample is inexpensive. See warts and skin tags on dogs.

This is general information, not a diagnosis. Please follow your own vet's advice.