Prevalence and Factors Associated with Abnormal Behaviors in Chilean Racehorses: A Direct Observational Study

Abstract

Stereotypies are considered a cause and symptom of impaired welfare, and have been associated with suboptimal husbandry systems. The aim of this study was to estimate the prevalence of stereotypic and other abnormal behaviors in Chilean thoroughbreds by direct observation, and examine their associations with biological characteristics and management practices. Seven hundred forty-three racehorses were observed directly, every 5 minutes during 1 hour before and after feeding, to identify behavioral disorders. A questionnaire was administered to handlers to obtain information about the animal and husbandry practices.The total observed prevalence rate of horses with one or more abnormal behavior was 11.03%. The total observed prevalence rates of stereotypies and abnormal behaviors were 6.32% and 5.52%, respectively. Horses at racetrack B presented more abnormal behaviors than those at racetrack A (P = .0092), and specifically, the prevalence of the oral group was higher (P = .0013). Mares presented a higher percentage of stereotypies (P = .0014), and the use of wood shaving bedding was positively associated with abnormal oral behaviors (P = .0027). Visual contact with conspecifics was possible for 86% of horses; the remaining had no social contact. Their diet consisted of a mixture of 71% of oats and 29% of roughage in average, presented between one and three times daily. No significant associations were found between the presence of visual contact, number of daily rations, yard, and percentage of roughage delivered, and stereotypy presentation (P > .05). In 43% of the cases with stereotypy, horses were impeded from performing the behavior by physical methods, avoiding the real problem and acting as a risk for animal welfare.