anyone know what this is on my dogs elbow?!

hi guys, last week my sister noticed this weird spot on my dogs elbow. i’m honestly not even sure how to describe it but it looks thick and is in an area with no hair, though her hair is covering some of it as you can see here in the images. after some research, i think it might be an elbow callus? my dog has been acting normal with no signs of discomfort, no itching (though it’s probably not a spot she can reach? lol) or bleeding and no redness.

i think it might be correct about it being a callus but wanted to get some opinions before taking my dog to the vet as she gets very stressed at the vet and want to save her the trip if possible. 😭

also marked as NSFW as this personally really triggers a phobia for me so i figured it might for others :-) lol thanks in advance!