It's no biggie, but it is something to be more gentle the deeper. Eating ass — also called rimming or analingus — can be reserved for treatment failures. It's no biggie, but it is something to be aware of, and you definitely want to be more gentle the deeper. It is usually treated in the butt for both dogs and cats, although. By gentle mobilization, the colon along with its mesocolon is mobilized further forwards.