Small red lump under dog's anus
I have a 12 year old terrier who suddenly developed a small, but raised, pea-sized, red lump located one centimetre under his anus. It is sitting directly under the anus and is not favoring either side. It's also red and bleeding, I suspect from irritation. I have noticed him scooting but he has been having normal bowel movements, is active as normal, eats and drinks like normal too. I have also tried manually expressing the anal glands but very little came out. It is my first time attempting it myself so I don't know if I'm doing it wrong.
I've called the vet and the appointment is next week but in the mean time, what could this be? I'm especially concerned because he is an older dog. Thanks for any insight.