Clinical questions are central to learning among veterinarians and drive informal learning during clinical practice. We set out to classify the clinical questions of practicing veterinarians using a taxonomy previously validated in human medicine. This prospective observational study used a convenience sample of 12 veterinarians in private, small-animal practices. We used three methods to gather clinical questions from the veterinarians: direct observation (asking veterinarians after each encounter), self-report via e-mail, and self-report via data-collection pocket cards. We then classified these questions using a validated taxonomy of question types, as well as by clinical category. A total of 157 clinical questions were collected; 99 were about dogs, 33 were about cats, and 25 were about multiple species or did not specify a species. Nearly half of the questions were rated as high priority, and only 11.5% as low priority. Over half of the questions (53%) were about treatment and 20% were about diagnosis. The two most common question types were "Is drug X indicated in situation Y or for condition Y?" and "How should I treat finding/condition Y (given situation Z)?" Overall, 5 of 57 question-type categories accounted for over half of the questions. The most common clinical categories were pharmacology, endocrine, musculoskeletal, and general surgery. This is the first study to systematically identify and classify the clinical questions of veterinarians. A better understanding of these questions can be used to inform the development of continuing-education (CE) activities that are directly responsive to the information needs of participants.