RESUMO
The Chilean horse is a breed of closed registry. Stall-walking and weaving are locomotor stereotypies that affect this breed, and genetic predisposition has been suggested for both conditions. The objective of the present study was to estimate heritability of stall-walking and weaving in Chilean horses. Owners of 2,098 horses registered in the Chilean horse Stud Book, which were or had been stabled for at least 1 year, were asked to provide for identification data of the animal and presence or absence of stall-walking and/or weaving. The Chilean Horse Stud Book was accessed online, to collect information on name and registration number of the sire and dam of each horse. The prevalence of stall-walking and weaving was calculated from the sample (n = 2,098). The database to estimate the heritability (h2) included all the sample horses (n = 2,098) and their sires and dams. Additionally, all the ancestors available in the Chilean Horse Stud Book were included in the database for 297 sampled horses including those with locomotor stereotypies. The genealogical database consisted of 7,187 individuals. The prevalence of stall-walking was 2.05% and prevalence of weaving was 1.43%, being more frequent in males (P < .05) for stall-walking. Heritability of stall-walking was low (h2 = 0.213 ± 0.08) and moderate for weaving (h2 = 0.435 ± 0.06). Heritability and prevalence of locomotor stereotypies found in the Chilean horse suggest that they are hereditary disorders, highly influenced by environmental factors.
Assuntos
Doenças dos Cavalos , Transtorno de Movimento Estereotipado , Animais , Predisposição Genética para Doença , Doenças dos Cavalos/epidemiologia , Cavalos/genética , Masculino , Prevalência , Comportamento EstereotipadoRESUMO
Resumen: El objetivo de este estudio fue determinar la prevalencia de estereotipias clásicas en caballos fina sangre de carrera del Hipódromo Chile, Chile, y la influencia del género y la edad. Se estudió la totalidad de los caballos fina sangre de carrera residentes en el Hipódromo Chile (n = 565). Por observación directa se determinó la presencia o ausencia de aerofagia, paseo circular en pesebrera o balanceo en cada caballo. Los resultados son expresados como porcentajes simples. Para el análisis estadístico se utilizó la prueba exacta de Fisher con un nivel de significancia de p < 0,05. La prevalencia total de estereotipias clásicas fue 6,19 % (2,68 % aerofagia, 2,33 % paseo circular en pesebrera y 1,79 % balanceo). No se encontró asociación entre las estereotipias y el género. Solo se encontró asociación entre la presencia de paseo circular en pesebrera y los caballos de 2 a 3 años de edad (p = 0,022). Los resultados sugieren que los caballos fina sangre de carrera del Hipódromo Chile presentan una prevalencia de estereotipias clásicas dentro del rango registrado previamente y que la edad es un factor de riesgo para el paseo circular en pesebrera.
Abstract: This study aimed to determine the prevalence of classic stereotypies in thoroughbred race horses at the Hipódromo Chile (Chile) and the influence of gender and age. All population of thoroughbred racing horses resident at the Hipódromo Chile was studied (n = 565). Direct observation determined the presence or absence of cribbing, stall-walking, or weaving in each horse. Results are expressed as simple percentages. For statistical analysis, Fisher's exact test was used with a significance level of p < 0.05. The overall prevalence of classic stereotypies was 6.19% (aerophagia 2.68%, stall-circling 2.33%, and weaving 1.79%). No association was found between stereotypies and gender. Association was only found between the presence of stall-circling and 2 to 3-year-old horses (p = 0.022). Results suggest that thoroughbred race horses at the Hipódromo Chile have a prevalence of classic stereotypies within the previously established range and that age is a risk factor for stall-circling.
Resumo: O objetivo deste estudo foi determinar a prevalência de estereotipias clássicas em cavalos puro sangue de carreira do Hipódromo Chile, no Chile, e a influência do gênero e da idade. Se estudou a totalidade dos cavalos puro sangue de carreira residentes no Hipódromo Chile (n = 565). Por observação direta se determinou a presença ou ausência de aerofagia, passeio circular em manjedoura ou balanceio em cada cavalo. Os resultados são expressos como porcentagens simples. Para a análise estatística se utilizou a prova exata de Fisher com um nível de significancia de p < 0,05. A prevalência total de estereotipias clássicas foi de 6,19 % (2,68 % aerofagia, 2,33 % passeio circular em manjedoura e 1,79 % balanceio). Não se encontrou associação entre as estereotipias e o gênero. Solo se encontrou associação entre a presença de passeio circular em manjedoura e os cavalos de 2 a 3 anos de idade (p = 0,022). Os resultados sugerem que os cavalos puro sangue de carreira do Hipódromo Chile apresentam uma prevalência de estereotipias clássicas dentro do rango registrado previamente e que a idade é um fator de risco para o passeio circular em manjedoura.
RESUMO
Objective. To determine the prevalence of classic stereotypies in Thoroughbred racehorses at the Club Hípico Concepción (CHC) in Chile and its association with sex and age. Materials and methods. The entire population of resident horses at the CHC was studied (n=341). Each horse trainer (n=23) was asked for the name, sex and age of the horses under his/her supervision. After that, all the animals were continuously observed inside their stalls for 8 hours by only one person, to record the absence or presence of classic stereotypies (cribbing, weaving, stall-walking). To analyze the data, the animals were divided by sex into 3 groups: stallions, geldings and mares. According to age, they were divided into 2 groups: < 5 years old and 5 years old or more. Descriptive statistics were used and association was tested using the chi square test using p≤0.05. Results. 13.2% of all CHC's horses displayed stereotypies: cribbing (4.99%), weaving (2.93%) and stall-walking (5.28%). No association was found between the presence of stereotypies and sex or age. Conclusions. Thoroughbred race horses at the CHC showed a high prevalence of classic stereotypies, especially stall-walking.
Objetivo. Determinar la prevalencia de estereotipias clásicas en caballos fina sangre de carrera (FSC) del Club Hípico Concepción (CHC), Chile y su asociación con el sexo y la edad. Materiales y métodos. Se estudió la totalidad de los caballos FSC (n=341) residentes en el CHC. A cada entrenador (n=23), se le consultó nombre, sexo y edad de los caballos a su cargo. Luego, con la finalidad de detectar la presencia o ausencia de estereotipias clásicas (aerofagia, balanceo y caminar en pesebrera), durante 8 horas una sola persona observó directamente los caballos mientras se encontraban en sus pesebreras. Los caballos se dividieron por sexo en 3 grupos: machos enteros, machos castrados y hembras. De acuerdo con la edad se dividieron en 2 grupos: <5 años y 5 años o más. Los resultados en la parte descriptiva se entregan como porcentajes simples y para el análisis estadístico de las variables sexo y edad, se utilizó la prueba de X2, con un nivel de significancia de p<0.05. Resultados. El 13.2% de los caballos de CHC presentaron estereotipias: aerofagia (4.99%), balanceo (2.93%) y caminar en pesebrera (5.28%). No se encontró asociación entre la presencia de estereotipias y las variables sexo y edad. Conclusiones. Los caballos FSC del CHC presentan una alta prevalencia de estereotipias clásicas, principalmente caminar en pesebrera.