Use of the semi-quantitative test with terbutaline sulfate for the identification of anhidrosis in Quarter Horses used in vaquejada events

Utilização do teste semi-quantitativo com sulfato de terbutalina para identificação de anidrose em equinos da raça Quarto de Milha utilizados em provas de vaquejada

ABSTRACT:

Anhidrosis, characterized by the partial or total reduction in sweat production, is a relevant condition in equines living in tropical climates, particularly those engaged in physical activity. This study evaluated the prevalence of anhidrosis in Quarter Horses used in the vaquejada sport, utilizing the semi-quantitative sweat test with terbutaline sulfate. Sixty Quarter Horses of both sexes, actively competing, were included in the study. The experimental procedure involved the intradermal application of a saline control solution and seven serial dilutions of terbutaline sulfate, ranging from 100 mg/L to 10^-6 mg/L, at predefined points in the cervical region. After solution application, the injection sites were assessed over a minimum of 20 minutes to observe the response to the test. The analysis criterion was based on the intensity of sweating at each concentration, enabling the classification of animals as healthy, partially anhidrotic, or completely anhidrotic. The study revealed a significant prevalence (75%) of partial anhidrosis among Quarter Horses. The results underscore the importance of accurate diagnosis of partial anhidrosis to understand its impact on equine health and performance.

Key words:
anhidrosis; exercise; sweat glands; thermoregulation