I'm not positive on this, as I'm not a vet....but....

I *thought* cysts were usually soft and squishy, and under the skin, not a pink bubble on the skin.

It sounds more likely to be some type of wart. Nebo had a large pink bump (looked like a slightly larger pencil eraser) on his leg removed when he was 4 months old.

Both of my 2 older dogs, especially Smokey, have these small pink growths on their skin. I've seen *many* dogs with these, it seems rather common in older dogs. I think they are harmless.

Let us know what the vet says, I hope it's nothing serious.