Allergic disease is a serious occupational health concern for individuals who have contact with laboratory animals. The principal respiratory symptoms include allergic rhinitis, conjunctivitis, and asthma. Urticaria (" hives") is the most common skin manifestation. The overall prevalence of allergic disease among laboratory animal handlers is about 23%, and respiratory allergy is much more common than skin allergy. Various studies have found annual incidence rates ranging from 2% to 12%. Prevention of animal allergy depends on control of allergenic material in the work environment. Personal protective equipment such as air filtering respirators should be used in addition to the other exposure control technologies where conditions require. Pre-placement evaluation and periodic medical surveillance of workers are important pieces of the overall occupational health program. The emphasis of these medical evaluations should be on counseling and early disease detection. The article gives recommendations for the content of the medical evaluations.