Through a written questionnaire, which was sent to a representatively distributed and randomly selected sample of Swiss horse owners, data of 2912 horses and ponies were acquired to extrapolate prevalence data of health disorders. General questions about the horse and associated factors of housing and use, as well as questions about the current health status and the occurrence of diseases and injuries had been asked. 718 horses (24.7% of the sample) had been examined by a veterinarian within the 12 months prior to the survey. Orthopaedic and traumatic disorders (41.5%) had the largest proportion, followed by gastrointestinal--(27.1%) and respiratory (14.0%) diseases. Half of the lameness cases occurred as a direct consequence of a injury. The injuries were associated with pasture/paddock (38.1%), kicking and biting (21.6%), boxstall (7.8%), terrain and hacking (13.4%), training (3.5%), competition (3.5%), transportation (3.0%) or other circumstances (9.1%). A change in feeding management up to 4 weeks before development of a colic episode occurred in 26.5% of all colic cases. In 13.8% of all respiratory cases the same disease was diagnosed in other horses in the same barn. 8.1% of all cases had to be treated surgically, 6.7% required hospitalization for several days. Information about diagnostic or therapeutic procedures was related to specific disease categories. In 25.6% of all cases diagnosed by a veterinarian alternative therapeutic methods were used either in addition to traditional medicine or exclusively.