Topic:Aggression
Aggression in horses is a behavioral response that can manifest in various forms, such as biting, kicking, or charging. It is often a reaction to environmental stimuli, social dynamics, or perceived threats. Understanding aggression in horses involves examining its triggers, expressions, and underlying causes. Factors such as genetics, past experiences, and management practices can influence aggressive behavior. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, manifestations, and management strategies for aggression in horses.
Harem stallion changes are not associated with diminished reproductive performance of females in semi-feral Konik polski horses (Equus caballus). Infanticide, related to a stallion's aggression toward a foal sired by another stallion, and feticide related to a new stallion's aggression and/or pheromonal influence (the Bruce effect) inducing loss of a fetus sired by another stallion, a female's counteraction to infanticide, have been proposed for domestic horses (Equus caballus) in human-managed conditions. The aim of the present study was, in conditions close to natural, to investigate the influence of the natural succession of a harem stallion on the mares' subsequent reproductive performance. In a population of semi-feral Konik polski...
Levelling playing field: synchronization and rapid facial mimicry in dog-horse play. Social play is a window on cognitive and communicative abilities of species. Inter-specific play, in particular, is a fertile venue to explore the capacity to correctly perceive and interpret signals emitted by partners. Up to now, most studies have focussed on dog-human play due to the important implications such studies have in understanding the peculiar relationship we establish with our pets. Here, we focussed on social play between dogs and horses. By using a set of specific keywords (dog, horse, play, friend) we selected 20 videos of dog-horse social play (with each session lasting >3...
Indicators of Horse Welfare: State-of-the-Art. Animal welfare is defined as a chronic state reflecting an individual's subjective perception of its situation. Because it is possible to be in a good welfare state and nevertheless experience acute fear or pain, and conversely, short-term positive emotions can be experienced during impaired welfare states, welfare as a chronic state has to be clearly distinguished from temporary states related to emotions, pain or stress. The evaluation of non-verbal individuals' welfare state, particularly in interspecific situations, is a real challenge that necessarily implies animal-based measures and req...
Effect of social organisation on interspecific differences in overmarking behaviour of foals in African equids. Overmarking remains an unstudied topic in juvenile mammals. We have previously documented a very high rate of overmarking by foals in four captive African equid species: mountain zebra (Equus zebra), plains zebra (Equus quagga), Grévy's zebra (Equus grevyi), and African wild ass (Equus africanus). African equids vary interspecifically in their social organisation. Since differences in social organisation affect many mammalian behaviours, in this study we investigated interspecific differences in overmarking behaviour of foals, analysing only cases where elimination of any other individual was...
Evaluating Animal-Assisted Interventions: An Empirical Illustration of Differences between Outcome Measures. Multiple authors have called for strong empirical evaluations to strengthen the foundation of Animal-Assisted Interventions. Carefully choosing the outcome measures of these studies is important, as choosing the wrong outcomes may lead to a failure to detect effects. The current study therefore compares and contrasts the use of several outcome measures, to assess the effect of an equine-assisted intervention for a child with Autism Spectrum Disorder: (1) a semi-structured interview with both parents, specifically designed for children with cognitive disabilities, (2) a general screening instru...
Housing Horses in Individual Boxes Is a Challenge with Regard to Welfare. Horses are mainly housed in individual boxes. This housing system is reported to be highly detrimental with regard to welfare and could trigger the expression of four behavioural indicators of a compromised welfare state: stereotypies, aggressiveness toward humans, unresponsiveness to the environment, and stress-related behaviours. The aim of this study was to identify housing and management factors that could alleviate the detrimental effects of individual boxes on welfare. A total of 187 horses were observed over 50 days by scan sampling. The impact of 12 factors was investigated on the expr...
First description of a fatal equine infection with Halicephalobus gingivalis in Portugal. Relevance for public health. Halicephalobus gingivalis is a small saprophytic rhabditid nematode, represented only by females with a typical rhabditoid oesophagus and one egg in the uterus, capable of infecting vertebrates. This opportunistic parasite present in the soil, manure and decaying humus, is thought to penetrate through previous injuries to the mouth, eyes and skin of horses and migrate to various organs. The brain is one such organ, where the females lay their eggs, leading to malacia and causing a sudden onset of neurological signs, such as anorexia, ataxia, urinary incontinence, blindness, decreased menace an...
Significance of Group Composition for the Welfare of Pastured Horses. We explore how herd composition and management factors correlate with frequencies of social interactions in horse groups. Since the welfare of horses correlates with low aggression levels and social contact opportunities, information of this kind is important. The data are a collection of records of social interactions of 426 Icelandic horses in 20 groups of at least eight horses. The complexities and limitations of the data prohibit useful statistical modelling so the results are presented descriptively. Interesting and informative patterns emerge which can be of use both in management and in...
Pharmacokinetics and selected pharmacodynamics of trazodone following intravenous and oral administration to horses undergoing fitness training. OBJECTIVE To measure concentrations of trazodone and its major metabolite in plasma and urine after administration to healthy horses and concurrently assess selected physiologic and behavioral effects of the drug. ANIMALS 11 Thoroughbred horses enrolled in a fitness training program. PROCEDURES In a pilot investigation, 4 horses received trazodone IV (n = 2) or orally (2) to select a dose for the full study; 1 horse received a vehicle control treatment IV. For the full study, trazodone was initially administered IV (1.5 mg/kg) to 6 horses and subsequently given orally (4 mg/kg), with a 5-week ...
Horses discriminate between facial expressions of conspecifics. In humans, facial expressions are rich sources of social information and have an important role in regulating social interactions. However, the extent to which this is true in non-human animals, and particularly in non-primates, remains largely unknown. Therefore we tested whether domestic horses (Equus caballus) could discriminate between facial expressions of their conspecifics captured in different contexts, and whether viewing these expressions elicited functionally relevant reactions. Horses were more likely to approach photographic stimuli displaying facial expressions associated with po...
Context-dependent third-party intervention in agonistic encounters of male Przewalski horses. One mechanism to resolve conflict among group members is third party intervention, for which several functions, such as kin protection, alliance formation, and the promotion of group cohesion have been proposed. Still, empirical research on the function of intervention behaviour is rare. We studied 40 cases of intervention behaviour in a field study on 13 semi-wild bachelor horses (Equus ferus przewalskii) in (a) standard social situations, and (b) when new horses joined the group (i.e. introductions). Only interventions in agonistic encounters were analysed. Eight of 13 animals directed inter...
Knowledge, attitudes and practices towards rabies: questionnaire survey in rural household heads of Gondar Zuria District, Ethiopia. Rabies is a fatal animal disease of significant public health importance. Domestic dogs are the main reservoir and transmitter of this disease particularly in developing countries. Even though rabies is a highly fatal disease, it is a preventable disease. Community awareness about rabies is one of the key components for prevention. This study describes the knowledge, attitudes and practices of a rural community in Gondar Zuria District, Ethiopia. Methods: A cross sectional study was conducted from March to June, 2013. A structured questionnaire was used to collect the data through face to face...
Water Use Patterns of Sympatric Przewalski’s Horse and Khulan: Interspecific Comparison Reveals Niche Differences. Acquiring water is essential for all animals, but doing so is most challenging for desert-living animals. Recently Przewalski's horse has been reintroduced to the desert area in China where the last wild surviving member of the species was seen before it vanished from China in the 1960s. Its reintroduction placed it within the range of a close evolutionary relative, the con-generic Khulan. Determining whether or not these two species experience competition and whether or not such competition was responsible for the extinction of Przewalski's horses in the wild over 50 years ago, requires ident...
Androgen receptor gene polymorphism in zebra species. Androgen receptor genes (AR) have been found to have associations with reproductive development, behavioral traits, and disorders in humans. However, the influence of similar genetic effects on the behavior of other animals is scarce. We examined the loci AR glutamine repeat (ARQ) in 44 Grevy's zebras, 23 plains zebras, and three mountain zebras, and compared them with those of domesticated horses. We observed polymorphism among zebra species and between zebra and horse. As androgens such as testosterone influence aggressiveness, AR polymorphism among equid species may be associated with diffe...
Animal-assisted therapy with chronic psychiatric inpatients: equine-assisted psychotherapy and aggressive behavior. Animal-assisted therapy (AAT), most frequently used with dogs, is being used increasingly as an adjunctive alternative treatment for psychiatric patients. AAT with larger animals, such as horses, may have unique benefits. In this randomized controlled study, equine and canine forms of AAT were compared with standard treatments for hospitalized psychiatric patients to determine AAT effects on violent behavior and related measures. Methods: The study included 90 patients with recent in-hospital violent behavior or highly regressed behavior. Hospitalization at the 500-bed state psychiatric hospit...
Age and group residence but not maternal dominance affect dominance rank in young domestic horses. We present a study focused on those factors influencing dominance position in young horses, with emphasis on the role of the mother. Horses, as other group-living polygynous mammals, form stable linear dominance hierarchies based on agonistic interactions. Higher dominance positions are believed to be connected, in both sexes, to better condition and higher reproductive success. Many variables play a role in forming the dominant-submissive relationships between horses; however, the maternal effect on the dominance position of the offspring still remains unclear, as do the possible mechanisms o...
The relationship of dominance, reproductive state and stress in female horses (Equus caballus). Maintaining a dominant position in a hierarchy requires energetically expensive aggressive displays and physical exertion. Lab based winner-loser studies, often conducted with individuals from non-social species, have shown that subordinates have higher stress hormone levels than dominant individuals. However, in wild studies on cooperative breeders, displays of aggression used to maintain dominance status are associated with elevated stress hormone levels. The effect of reproductive state on dominance and stress has not been addressed within either of these situations. The purpose of this stu...
Linking social environment and stress physiology in feral mares (Equus caballus): group transfers elevate fecal cortisol levels. Feral horses (Equus caballus) have a complex social structure, the stability of which is important to their overall health. Behavioral and demographic research has shown that decreases in group (or band) stability reduce female fitness, but the potential effects on the physiological stress response have not been demonstrated. To fully understand how band stability affects group-member fitness, we need to understand not only behavioral and demographic, but also physiological consequences of decreases to that stability. We studied group changes in feral mares (an activity that induces instabilit...
[Nutritional laminitis–preventive measures for the obese horse]. Nutrition-induced laminitis is often caused by i) fermentation of large amounts of carbohydrates in the hindgut (usually fructans from grass or starch from cereals), which cause the release and absorption of microbial toxins and ii) insulin resistance induced by being overweight (equine metabolic syndrome). Both causes can act together. Overweight horses with a history of laminitis need to reduce body weight to prevent further incidences of laminitis. Weight reduction occurs normally on a diet of late-cut hay, a hay-straw mixture (maximally one third straw to prevent constipation) or grass see...
Pattern of social interactions after group integration: a possibility to keep stallions in group. Horses are often kept in individual stables, rather than in outdoor groups, despite such housing system fulfilling many of their welfare needs, such as the access to social partners. Keeping domestic stallions in outdoor groups would mimic bachelor bands that are found in the wild. Unfortunately, the high level of aggression that unfamiliar stallions display when they first encounter each other discourages owners from keeping them in groups. However, this level of aggression is likely to be particularly important only during group integration, when the dominance hierarchy is being established,...
Adaption of horses to a novel dynamic feeding system: movement and behavioural responses. Many domestic horses and ponies are sedentary and obese due to confinement to small paddocks and stables and a diet of infrequent, high-energy rations. Severe health consequences can be associated with this altered lifestyle. Objective: The aims of this study were to investigate the ability of horses to learn to use a dynamic feeder system and determine the movement and behavioural responses of horses to the novel system. Methods: A dynamic feed station was developed to encourage horses to exercise in order to access ad libitum hay. Five pairs of horses (n = 10) were studied using a randomised...
Use of a deslorelin implant for influencing sex hormones and male behaviour in a stallion – Case report. This case report describes the use of a subcutaneously applied 4.7-mg deslorelin acetate implant in a three-year-old Arabian crossbred stallion showing unwanted strong male behaviour. Following deslorelin acetate implantation the stallion showed a short transitional increase in male behaviour. A 'gelding-like' behaviour was noted 15 days (D15) after treatment. The horse was surgically castrated at the owners request at D52 after treatment. Serum testosterone, oestradiol-17β and oestrone sulphate values decreased after deslorelin acetate implantation, but serum LH and FSH levels remained uncha...
64, XX, SRY-negative, testicular DSD syndrome in a Lusitano horse. Here is reported a disorder of sex development found in the Portuguese Lusitano horse breed. The complex genital phenotype included mammary glands, abdominal testes without epididymis, connected through oviducts to pelvic hypoplastic uterine horns and fused vulvar labia majora from which protruded ventrally a penis-like structure. This structure was presented in a reversed position, the urethral opening placed dorsally in the glans. However, it was functional both for micturition and erection. The horse exhibited female micturition posture and aggressive male-like behaviour, including flehmen,...
Influence of an active stable system on the behavior and body condition of Icelandic horses. Horses are often stabled in individual boxes, a method that does not meet their natural needs and may cause psychical and musculoskeletal diseases. This problem is particularly evident in Iceland, where horses often spend the long winter periods in cramped boxes. The aim of this study was to analyze the suitability of a group housing system in Iceland, but the results are also applicable to horses of other regions. Eight Icelandic horses were observed in an active stable system, and their behavior and time budget were recorded. Movement and lying behavior were studied with ALT (Activity, Lying...
Adults may be used to alleviate weaning stress in domestic foals (Equus caballus). The present study aims to investigate whether the presence of unrelated adult horses at weaning would reduce the social stress of weaning and the emergence of undesirable behaviours. We tested this hypothesis in 32 domestic foals by comparing short and medium term behavioural and physiological responses to weaning in foals maintained in homogeneous groups of peers (PW) to those of foals grouped with both peers and unrelated adults (AW). In total, three trials were conducted, which each trial consisting of one AW group and one PW group. In all foals, weaning was followed by increased vocalizati...
Granulosa theca cell tumour in a pregnant mare: concentrations of inhibin and testosterone in serum before and after surgery. A 14-year-old Thoroughbred mare was presented for evaluation of a rapidly enlarging ovary at 73 days gestation. The mare's owner reported behavioural changes in the mare since she returned from stud, notably aggression towards other horses. Results: Transrectal palpation and ultrasonography of the reproductive tract revealed a viable pregnancy, an enlarged, multiloculated right ovary, and a normal-sized left ovary with a corpus luteum present. Concentrations of inhibin and testosterone in serum were 13.8 ng/mL and 1,150 pg/mL, respectively, being markedly higher than reference ranges. Concentr...
[Automatic feeding systems for horses in group housing systems with regard to animal welfare. Part 2: Comparison of different automatic feeding systems]. Comparison with regard to animal welfare of different automatic feeding systems for hay and concentrate in group housing systems for horses using parameters of ethology and physiology. Methods: Parameters of research comprised: duration of stay, frequency of visit, threatening behaviour with and without risk of injury, and avoiding behaviour as well as heart rate and injuries of the integument. 452 horses were observed at the feeding area of 32 run-out-sheds. Every group of horses was continuously observed following the pie chart system for 24 hours. Results: The "walk-through" station signifi...
Olfactory recognition of individual competitors by means of faeces in horse (Equus caballus). Living in complex social systems requires perceptual and cognitive capacities for the recognition of group membership and individual competitors. Olfaction is one means by which this can be achieved. Many animals can identify individual proteins in urine, skin secretions, or saliva by scent. Additionally, marking behaviour in several mammals and especially in horses indicates the importance of sniffing conspecifics' faeces for olfactory recognition. To test this hypothesis, we conducted two separate experiments: Experiment 1 addressed the question of whether horses can recognise the group memb...
Partners with bad temper: reject or cure? A study of chronic pain and aggression in horses. Experiencing acute pain can affect the social behaviour of both humans and animals and can increase the risk that they exhibit aggressive or violent behaviour. However, studies have focused mainly on the impact of acute rather than chronic painful experiences. As recent results suggest that chronic pain or chronic discomfort could increase aggressiveness in humans and other mammals, we tested here the hypothesis that, in horses, aggression towards humans (a common source of accidents for professionals) could be linked to regularly reported vertebral problems of riding horses. Results: Vertebra...