Police horses with certain personality traits have a greater likelihood of showing abnormal behaviours, according to researchers.
The study, which involved 46 police horses in Brazil, identified multiple abnormal behaviours motivated by factors such as diet and lack of social contact.
The results showed that personality was an important component in evaluating welfare, since correlations were found between not only personality traits and abnormal behaviours, but between personality traits and health problems.
The study team, Ivana Schork, Cristiano de Azevedo and Robert Young, found that passive, stubborn, and confident horses were better suited to police work.
“The ability to classify horses according to their personalities could help in selecting horses most suitable for patrolling, thereby helping to reduce behavioural problems and increasing animal well-being,” they reported in the open-access journal PLOS ONE.
The trio said an animal’s welfare depended on its capacity to adapt to the environment in which it lived.
“This adaptation is directly associated with the quality of the environment and to the possibility of expressing natural behaviours.”
Horses kept in stables often displayed a range of abnormal behaviours related to lack of control over their environment, which can lead to behavioural and health problems.
An individual’s personality also plays an important role in its susceptibility and resilience to the development of diseases and abnormal behaviour.
“Thus, an evaluation of horses’ personalities could be crucial to selecting individuals best able to cope with different work activities.”
The police horses used for the study were maintained in semi-confined conditions in the city of Belo Horizonte, in the Brazilian state of Minas Gerais.
The horses, comprising 20 geldings and 26 mares, were used for urban patrols, with regular shifts. All had been in work for at least a year.
The animals, who all belonged to the Brazilian Sport Horse breed, had an average age of 10.37 and had each undergone a year of training as youngsters.
The normal work load for the horses consisted of an eight-hour shift every other day, in cycles of 45 minutes patrolling followed by 15 minutes of rest. When not patrolling, the horses were maintained in stalls and did not perform other activities.
The individual masonry stalls measured 2 metres by 2.5 metres with wooden doors and cement floors, with no shavings or bedding.
The animals were fed six times a day, alternating 2kg of hay and 2kg of a concentrate mix of grains, and had access to water at will. The horses had weekly veterinary health check-ups.
The researchers performed different tests to investigate each horse’s behaviour, personality and welfare.
They undertook a frustration test, a novel object test, behavourial tests, and assessed each horse’s personality using a checklist-style questionnaire carried out by three veterinarians and each horse’s rider.
Each animal’s physical health was assessed through their veterinary records.
The researchers found that the horses exhibited abnormal behaviours in rates varying from 5 to 15% during the different tests, with many of these behaviours associated with personality traits.
“The most curious, cooperative and intelligent horses exhibited more abnormal behaviours than the more passive and stubborn ones,” they said.
“Aggressive, insecure, irritable and hardworking horses also presented more abnormal behaviours than the horses with confident and reliable traits.
“In general, more intelligent, playful and curious horses presented more lameness than horses with other personality traits.”
The authors noted that the horses received their training at the age of two, when horses were developing their social bonds as they left their maternal groups.
“It has been suggested that the suppression of emotions by horses while training contributes to a decreased welfare.
“These animals are evolutionarily programmed to escape situations like these, not to confront them. Hence, this type of routine could induce the occurrence of abnormal behaviours, especially in foals.
“The fact that the most curious, cooperative and intelligent horses exhibited more abnormal behaviours reinforces the idea that the demanded obedience during training and daily patrols could cause welfare problems to these individuals.
“Particularly, in our subjects, along with the non-ideal environment, personality appears to be a key factor determining how the animals responded to their environment.”
“In our study,” they continued, “the expression of abnormal behaviours was also correlated with personality traits.
“In general, intelligent, cooperative, curious, equable and playful horses were more prone to express oral (crib-biting and lip-twisting) and locomotor (head-shaking, kicking and pawing) abnormal behaviours than others.”
The reason why intelligent and curious horses tended to develop more abnormal behaviours was not yet clear, they said, but it was possible they learned such behaviours from other individuals.
“Lastly, aggressive and irritable horses are known to develop repetitive abnormal behaviours because they are not able to deal with the frustration of a restricted environment, such as stabling.
“In the present study, aggressive and irritable horses showed less expression of licking, lip-smacking and stomping. Maybe these horses did not possess higher levels of anxiety that could culminate in an abnormal response, thereby dealing better with stress.”
Active horses showed a propensity to express more abnormal behaviours, whereas irritable and playful horses showed the propensity to express less abnormal behaviours.
The authors concluded that classifying of horses according to their personalities could help in choosing the most suitable individuals for patrolling, thereby increasing animal welfare. However, this would need validating through long-term studies.
Schork IG, de Azevedo CS, Young RJ (2018) Personality, abnormal behaviour, and health: An evaluation of the welfare of police horses. PLoS ONE 13(9): e0202750. https://doi.org/10.1371/journal.pone.0202750