Hi Paul, it sounds like Mr Dooley has an ear infection, being that its red and warm, and he's scratching at it. Also tilting the head, and favouring it, not letting you touch his ear are all signs that he might have an ear infection. If he will let you, you can try cleaning his ear with an ear cleaner, or some hydrogen peroxide, you can also try using some over the counter Polysporin eardrops from the drugstore. Since you are going to the vets tomorrow to have his nails trimmed, you can have him check his ear at the same time. Cleaning out his ear may help, but he may need an antibiotic to clear it up, but the vet is the best person to assess that. I hope he feels better soon. Please keep us posted as to what the vet said.