No harm comes to any of the numerous dogs on-screen. However, the whole movie revolves around rescuing a chihuahua - and other animals with it - from an animal (cosmetics) testing facility. We see a very brief glimpse of the dog in the test lab; nothing awful is being done to it at that moment.
The person whom the commenter Mik describes as "a male in a wig" looked like a trans woman to me... In-universe it's a cool thing if the Delta Nu sorority had a transgendered member - but I'm sure the movie placed the person in that context as a joke.