Stereotypic horses (Equus caballus) are not cognitively impaired.

The research article investigates whether horses with stereotypic behaviour, specifically crib-biting, are cognitively less flexible than healthy controls. The study disputes the widespread belief that stereotypic animals suffer cognitive impairment, concluding that any cognitive underperformance observed in these horses may occur if they are prevented from crib-biting as a stress-management tool.

Study Background

• Stereotypies in animals are considered a reaction to genetic predisposition in combination with sub-optimal housing conditions. Crib-biting in horses is a prevalent stereotypy believed to aid them in coping with stressful scenarios.
• A leading hypothesis positions that animals demonstrating stereotypies are less flexible, cognitively speaking, than healthy ones because of the sensitization of a specific brain area, the basal ganglia.

Study Objectives and Methodology

• This research aimed to scrutinize this hypothesis by comparing crib-biting horses and healthy controls during a cognitive task known as reversal learning, frequently used to identify basal ganglia functionality.
• The procedure involved subjecting the horses to four learning tasks; initial and secondary acquisition, and their reversals.
• Outcomes were measured based on the number of trials required to reach specified criteria and physiological responses like heart rate and heart rate variability.
• Significantly, the researchers did not try to stop the crib-biters from executing their stereotypic behaviour during the experiment.

Findings and Conclusions

• The results showed that the first reversal learning task took the most trials, which endorse its challenging characteristic.
• Notably, the second reversal learning task required noticeably fewer trials, inferring a generalisation learning process.
• However, no significant variations in performance were detected between the stereotypic and control group; both groups required a similar number of trials and showed identical physiological responses.
• These results challenge the widespread perception that horses with crib-biting and stereotypic behaviour in general, suffer from cognitive impairments.
• The conclusion drawn from the study is that cognitive underperformance in stereotypic horses might occur only if they are stopped from crib-biting, which they use to cope with the stress.