Ethological, endocrinological, and gastroscopic evaluation of crib-biting Colombian creole horses

Abstract

Crib-biting is an abnormal behavior, classified as one of the most classical oral stereotypies in horses. Its etiology is poorly understood and is considered multifactorial, being associated with negative health effects. The objective of this study was to explore the ethological, endocrinological, and gastroscopic findings related to crib-biting in Colombian creole horses (CCHs). Two study groups were defined. The first group was composed of 19 CCHs (7 females and 12 males) presenting crib-biting (crib-biting group), with an average age of 7.6 ± 3.8 years, an average weight of 332 ± 42 kg, and an average body condition score (BCS) of 6/9 ± 1. The second group was composed of 17 CCHs (11 females and 6 males) without crib-biting (non–crib-biting group), with an average age of 6.1 ± 4 years, an average weight of 311 ± 33 kg, and an average BCS of 5/9 ± 1.5. Both groups were subjected to ethograms, am/pm serum cortisol measurement, and gastric and fecal pH measurement. The degree of stress (no stress, low stress, medium stress, and high stress) (P = 0.0037), gastric pH (P = 0.0012), and the different degrees of ulceration in the squamous gastric mucosa (P = 0.0015) were found to be associated with the crib-biting behavior. We hypothesize is that the control of this stereotypical behavior may be a mechanism to reduce the effect of stress and gastric ulceration–inducing factors in horses. Therefore, longitudinal behavioral studies, considering continuous monitoring of the hormonal dynamics and the genesis of this behavior, are needed.