While I do like animals (Dog Person here) I do have the unfortunate luck of being allergic to both dogs and cats, as well as pretty much anythin else with fur or feathers
My reaction can range from minor to severe all depending on the breed, age, and activity of the animal. For some pets, especially puppies and kittens who produce more dander, just walking in a house or apt where one has been recently will set off the itchy eyes, congestion and hives, keeping them locked in another room or a crate is too little to late. Because of all that, unless I have specific information to the negative, I will ask a lady if she has had any pets at her incall. If she does, I usually explain the allergies and try to arrange an outcall. Most every provider I have come across with a pet has been understanding and accommodating. Some, even though I have never asked or complained about it, have even waved the outcall fee differential because of the situation. They ended up getting it back as a tip or in presents, but it was a well appreciated nice gesture none the less.