Abstract: “Clicker training” is a popularly promoted training method based on operant conditioning with the use of a secondary reinforcer (the clicker). While this method draws from theories of learning and is used widely, there has been little scientific investigation of its efficacy. We used 60 horses, Equus callabus, and assigned each horse to one of six reinforcement protocols. The reinforcement protocols involved combinations of reinforcers administered (primary versus secondary plus primary), schedule of reinforcement (continuous versus variable ratio), and reinforcers applied during extinction (none or secondary). There were no differences (P>=0.11) between horses which received a secondary reinforcer (click) followed by the primary reinforcer (food) and those which received only the primary reinforcer (food) in the number of trials required to train the horses to touch their noses to a plastic cone (operant response). There also were no differences (P>=0.12) between horses which received the secondary reinforcer plus primary reinforcer and those which received only the primary reinforcer in regards to the number of trials to extinction. We conclude that there is no difference in the amount of training required to learn the operant task or in the task's resistance to extinction between horses that received a secondary reinforcer followed by a primary reinforcer versus horses which received only a primary reinforcer.

Abstract: The flehmen response is commonly seen in most ungulates as well as in several other species (e.g. felids). The behavior is most often thought to be part of the sexual behavioral repertoire of males. One reigning hypothesis suggests that this behavior allows the male to determine the estrous state of a female through the chemosensory functions of the vomeronasal organ. However, females and young of both sexes also exhibit this behavior. Horse foals most frequently show the flehmen response during their first month of life with colts showing the behavior more often than fillies. This study tested the flehmen response on male and female foals throughout their pre-pubertal period. Foals were separately presented estrous and non-estrous urine weekly during the first month of life and then monthly until they were approximately 7 months of age. No significant differences were found between male and female foals for the following variables: latency to flehmen, duration of flehmen, frequency of flehmen and sniffs.

Abstract: Abstract Considering the ever-growing demand of various breeding organizations for an objective, inexpensive, reliable, and easily conducted assessment of the behavior of horses, the aim of our study was to implement a novel-object test and a startling test into any kind of breeding performance testing to assess horses' temperament. Additionally, the influence of testing areas (familiar or unfamiliar), riders, and horse factors such as levels of training, breed, and age were of interest. Furthermore, recommendations for the practical implementation concerning the parameters should be given. Therefore, 1,028 horses over a period of 3 years participated in a temperament test consisting of 5 different stimuli. The horses were either ridden (61.8 %) or led by hand (38.2 %) by an unfamiliar professional rider (N = 43) or a familiar rider (N = 20). Live behavioral observations were taken by a trained observer. Overall, horses' scores for reactivity in the present temperament test were distributed over the whole scale, with lower means and higher standard deviations (6.7 ± 2.2-7.6 ± 2.1) than corresponding scores from the conventional personality evaluation in performance tests (7.7 ± 0.8-8.2 ± 0.5; P < 0.01). High correlations (r = 0.3-0.9; P < 0.001) between the scores for reactivity and the other behavioral parameters (emotional expression, activity, time to calm down, rider's aids) show a large influence of these parameters in assessing the horses' temperament. Factors like breed type, sex, and age had significant influences (P < 0.001) on different scores of the temperament test. In most cases, the rider or handler had no influence on the different scores assessed during the temperament test. The training level and the testing modus never had a significant influence on different scores. Only the testing station or location had a small influence on the scores for the stimulus “bridge” in some horses. Based on the results, it could be concluded that an implementation of a temperament tests into performance testing is possible during various types of testing procedure. Especially the assessment of reactivity, emotional expression, interest in the stimulus and rider's aids during and after passing the stimulus, as well as the time to calm down are important parameters for analyzing the horses' personality.

Abstract: When Christopher Columbus and his men embarked on the second Colombian expedition to the New World (1493), the crew suffered from fever, respiratory symptoms and malaise. It is generally accepted that the disease was influenza. Pigs, horses and hens acquired in Gomera (Canary Islands) traveled in the same ship. The pigs may well have been the origin of the flu and the intermediary hosts for genetic recombination of other viral subtypes. The Caribbean archipelago had a large population of birds, the natural reservoir of the avian influenza virus. In this ecological scenario there was a concurrence of several biological elements that had never before coexisted in the New World: pigs, horses, the influenza virus and humans. We propose that birds are likely to have played an important role in the epidemiology of the flu occurring on the second Colombian trip, which caused a fatal demographic catastrophe, with an estimated mortality of 90% among the natives.

Abstract: Over 45 million years of evolution the horse developed to a highly specialized animal in anatomy, physiology and behavior. No other animal had influenced the economic and cultural history of men to such extent. Hunting prey since the ice age, domesticated 4000 B.C. and used for thousands of years as unique animal all over the world has attained a new role today as partner in sport, as companion animal and even as cotherapeutic. The well known behavioral demands in use and keeping are still often not fulfilled.