Behavioural assessment of pain in 66 horses,with and without a bit

Horses can be ridden with or without a bit. Comparing the behaviour of the same horse in different modes constituted a ‘natural experiment’. Sixty-nine behaviours in 66 bitted horses were identified as induced by bit-related pain and recognised as forms of stereotypic behaviour. A prototype questionnaire for the ridden horse was based on 6 years of feedback from riders who had switched from a bitted to a bit-free bridle. From a template of 69 behavioural signs of pain derived from answers to the questionnaire, the number of pain signals shown by each horse, first when bitted and then bit-free, was counted and compared. After mostly multiple years of bit usage, the time horses had been bit-free ranged from 1 to 1095 days (median 35). The number of pain signals exhibited by each horse when bitted ranged from 5 to 51 (median 23); when bit-free from 0 to 16 (median 2). The number of pain signals for the total population when bitted was 1575 and bit-free 208; an 87% reduction. Percentage reduction of each of 69 pain signals when bit-free, ranged from 43 to 100 (median 87). The term ‘bit lameness’ was proposed to describe a syndrome of lameness caused by the bit. Bit pain had a negative effect on proprioception, i.e. balance, posture, coordination and movement. Only one horse showed no reduction in pain signals when bit-free. The welfare of 65 of 66 horses was enhanced by removing the bit; reducing negative emotions (pain) and increasing the potential to experience positive emotions (pleasure). Grading welfare on the Five Domains Model, it was judged that – when bitted – the population exhibited ‘marked to severe welfare compromise and no enhancement’ and – when bit-free – ‘low welfare compromise and mid-level enhancement.’ The bit-free data were consistent with the ‘one-welfare’ criteria of minimising risk and preventing avoidable suffering.     

Prevalence of behavioral disorders in the Swiss horse population

In the Swiss horse population, the prevalence of conspicuous behaviours (behavioural disorders and stable vices) was recorded with a written questionnaire in a representative survey among 1861 horse yards, and the occurrence of the stereotypic behavioural disorders crib-biting, weaving and boxwalking was analysed with emphasis on their association with horse specific (breed, age, sex) and environmental factors (e.g. housing system, nutrition, management and utilisation). 622 horse yards with a total number of 2536 horses answered to the questionnaire, and conspicuous behaviours were described for 418 horses (16.5%). Thereof, the most common stereotypic behavioural disorders with a potential negative impact on animal welfare, crib-biting, weaving, and/or boxwalking were named for 89 horses (3.5%). Stable vices (e.g. shying, bucking, aggressivity against humans) were noted for 47 horses (1.9%). For 281 horses (11.1%) conspicuous behaviours such as pawing, lip-liking, head shacking, kicking stall were given; these can be categorised as behavioural disorders or as stable vices depending on their intensity and causation. Data analysis data revealed a number of statistically significant associations between genetic factors (breed), housing, management practices, utilisation and the three stereotypies. The strongest influence on the degree of behavioural disorders had the breed as well as the extent of direct social contact with other horses, free movement on pasture, feeding pattern and regular utilisation.     

Exploring lay perceptions of the causes of crib‐biting/windsucking behaviour in horses

Reasons for performing study: Crib‐biting/windsucking behaviour has important consequences for equine health and welfare. Lay perceptions of health and illness are of interest to medical sociologists, providing important information to medical practitioners, but have infrequently been applied in veterinary research. Objectives: To demonstrate how lay epidemiology can be applied within veterinary research by exploring the lay perceptions regarding the causes of crib‐biting/windsucking behaviour in horses. Methods: Informants were recruited from professional and amateur horse owners who had or had not owned/cared for a horse that exhibited crib‐biting/windsucking behaviour. In‐depth interviews were used to examine perceptions about the development of this behaviour within each group until a ‘saturation’ of themes emerged. Results: The main themes that emerged as causes of crib‐biting/windsucking behaviour were ‘boredom’, ‘stress’ and ‘habit/addiction’. In the group of owners/carers who did not have direct experience of this type of behaviour, ‘copying’ from other horses emerged as a strong theme and they stated that they would not wish to own a crib‐biting/windsucking horse. In contrast, those who had direct experience of horses demonstrating this behaviour did not believe copying was a cause based on their own observations and would not be put off purchasing or caring for another horse displaying this behaviour. Conclusions: Perceptions about what causes crib‐biting/windsucking was influenced by whether or not informants had personal experience of horses demonstrating this behaviour. The three main themes that emerged have some justification based on current research and highlight the need for further investigation into the underlying pathophysiology of crib‐biting/windsucking behaviour. Potential relevance: Qualitative approaches to health, disease and behaviour have an important role in the medical field and are applicable to veterinary research.     

Risk factors associated with behavioural disorders of crib-biting,weaving and box-walking in Swiss horses

REASONS FOR PERFORMING STUDY: Studies on the prevalence of behavioural disorders in horses and on associated risk factors have revealed inconsistent results. There are many studies on the neuropharmacological, surgical or mechanical therapy of stereotypies, but little is known about their causation. OBJECTIVES: To explore risk factors associated with the occurrence of behavioural disorders in horses. METHODS: A sample of horse owners, selected randomly and representative for Switzerland, was contacted in a postal survey. Answers were provided for 622 stables (response rate 35.2%). Individual data of 2,341 horses were examined with path analysis (multivariable linear and logistic regression), and adjustment made for possible confounding effects due to age and breed. RESULTS: Out of 60 possible risk factors, 11 were associated with the outcome at the univariable level (null-hypothesis path model) and 3 factors remained after the backward logistic regression procedure. Mature Warmbloods and Thoroughbreds, assessed by the owners to be reactive, fed 4 times a day and without daily pasture, had increased odds of displaying crib-biting, weaving and box-walking. Furthermore, indirect associations of 5 factors with the outcome were identified. CONCLUSIONS: The final logistic regression model of risk factors leads to the hypotheses that causal prevention of stereotypic behaviours should be based upon housing and management conditions which allow tactile contact with other horses (e.g. mutual grooming), daily free movement (paddock or pasture), as well as the provision of high amounts of roughage but of little or no concentrates. POTENTIAL CLINICAL RELEVANCE: It is one of the aims of population medicine to prevent the development of behavioural disorders. Further research is needed to test the concluding hypotheses in experimental studies or to verify them in the context of similar observational studies.     

Equine stereotypic behaviors: Causation,occurrence, and prevention

There are strong suggestions that equine stereotypies are connected to poor welfare and a suboptimal management and/or stabling environment. Different forms of equine stereotypic behaviors have been described. Crib biting, weaving, and box walking are considered the most prevalent. Several studies have been conducted to establish links between the underlying causes and potential function of such behaviors. Both experimental and epidemiological studies have indicated management factors specifically feeding practices, housing conditions, and weaning method as crucial in the development of stereotypies in stabled horses. Some neurological studies on equine stereotypy demonstrated some forms of central nervous system dysfunction as being associated with the performance of stereotypic behaviors. Different researchers hypothesized that the functional significance of stereotypies is that they reduce stress in captive environments and should thus be considered as a coping mechanism. In contrast, the owner's perspective is often that a stereotypic horse has a “stable vice” that needs to be stopped, and different kinds of methods have been developed to control or regulate stereotypic behaviors. However, if the stress-reducing hypothesis is correct, controlling stereotypic behaviors particularly by physical and surgical approaches without addressing the underlying causes is of great concern to the horse's welfare. Although there is ongoing uncertainty about the exact function, the growing knowledge about causation should be applied: under all circumstances prevention is better than cure.     

A cross-sectional study of geriatric horses in the United Kingdom. Part 2: Health care and disease

Reasons for performing study: Geriatric horses (aged ≥15 years) represent a substantial proportion of the equine population, yet very few studies have investigated the prevalence of diseases within the UK equine geriatric population. Objectives: To describe the provision of routine preventive health care measures, prevalence of clinical signs of disease and the prevalence of owner reported diseases. Additionally, the effect of increasing age on the provision of preventive health care and the presence or absence of clinical signs and disease was assessed. Methods: A cross‐sectional study was conducted, surveying a randomly selected sample of veterinary registered owners with horses aged ≥15 years, using a self‐administered postal questionnaire. Results: As geriatric horses increased in age, there was a reduction in the provision of preventive health care measures, such as vaccination, farrier care and routine veterinary checks. Only 68.7% of horses had received a routine veterinary visit within the previous 12 months. Owners frequently observed clinical signs in their animals, with 77% reporting at least one clinical sign of disease. Increasing age was associated with increased reporting of many clinical signs of disease. Over half (58%) of horses had at least one episode of disease within the previous 12 months, yet only 31% of owners reported that their animal currently suffered from a known disease or disorder. Conclusions and potential relevance: Although owners frequently observed clinical signs in their aged horse, there may be incorrect or under recognition of many diseases and health problems. Reduced frequency of routine preventive health care measures, along with suboptimal owner recognition of health and welfare problems may lead to compromised welfare in the geriatric population.     

Demographics, management, and welfare of nonracing horses in Prince Edward Island

There are no detailed, representative, horse-level data about equine management practices in different parts of Canada. To help address this, the demographics, management, and welfare of 312 nonracing horses in Prince Edward Island were examined in a randomized, horse-level survey during summer 2002. Owners completed a pretested questionnaire, and a veterinarian examined each horse. Owners were experienced caregivers and the horses were generally in good condition. Areas for improvement included parasite control, dental and hoof care, and tail docking. The mean fecal egg count was 428 eggs per gram; 76% of owners never removed manure from the pasture. Sixty-two percent of horses had never had a veterinary dental examination. Many horses had hoof defects (excessively long hooves, 26.8%; hoof wall breaks, 32.0%; and white line disease, 8.5%). Many (54.9%) draft horses had docked tails. These results suggest owners might benefit their horses by receiving education in aspects of equine care.     

Investigating the opinions of donkey owners and veterinary surgeons towards pain and analgesia in donkeys

The aim of this questionnaire‐based study was to identify which analgesics are currently prescribed to donkeys in clinical practice and to collect opinions from veterinary surgeons and donkey owners on the importance of different pain‐related behaviours in donkeys. Questionnaires were completed by 143 veterinary surgeons and 93 donkey owners. Phenylbutazone, flunixin, detomidine and butorphanol were reported as the most frequently used analgesics in donkeys. Most veterinary surgeons reported administering these drugs at the horse dose rate and dosing interval, which may be inappropriate in the donkey. Four pain‐related behaviours were identified as very important by veterinary surgeons and owners: dullness for colic‐associated pain, keeping the foot lifted, and lameness for foot and limb pain and inability to chew properly for head and dental pain. This is a more limited behavioural repertoire than has recently been identified to be associated with pain in the donkey and suggests that the respondents were reporting perceived wisdom as to what people think are the behavioural signs associated with pain or were not interpreting pain‐related behaviours correctly.     

Management factors affecting stereotypies and body condition score in nonracing horses in Prince Edward Island

In North America, there are few representative data about the effects of management practices on equine welfare. In a randomized survey of 312 nonracing horses in Prince Edward Island (response rate 68.4%), owners completed a pretested questionnaire and a veterinarian examined each horse. Regression analyses identified factors affecting 2 welfare markers: body condition score (BCS) and stereotypic behavior. Horses' BCSs were high (mean 5.7, on a 9-point scale) and were associated with sex (males had lower BCSs than females; P < 0.001) and examination date (P = 0.052). Prevalences of crib biting, wind sucking, and weaving were 3.8%, 3.8%, and 4.8%, respectively. Age (OR = 1.07, P = 0.08) and hours worked weekly (OR = 1.12, P = 0.03) were risk factors for weaving. Straw bedding (OR = 0.3, P = 0.03), daily hours at pasture (OR = 0.94, P = 0.02), and horse type (drafts and miniatures had a lower risk than light horses; P = 0.12) reduced the risk of horses showing oral stereotypies. Some of these results contradict those of other studies perhaps because of populations concerned.     

The strengths of statistical techniques in identifying patterns underlying apparently random behavioral problems in horses

The inability of owners to recognize patterns behind the seemingly disparate or random behavior problems expressed by their horse has major welfare implications. Principal components analysis has been successfully used to explore relationships between individual behavior problems in dogs, and it may be a valuable tool in recognizing relationships between problem behaviors in horses. Here, we report how principal components analysis has been used to identify relationships underlying individual behavior problems in horses using data generated from a large-scale Internet survey of United Kingdom leisure horses. Horse-level data on the performance of 44 individual behavior problems, encompassing stable-related and handling behavior problems, prefeeding behavior problems, and ridden behavior problems, were reduced to 12 behavior problem components. Each component was composed of groups of behavior problems that may share a common underlying etiology. These findings demonstrate the value of statistical techniques in identifying associations between apparently random behavior problems. Recognizing relationships between individual problems may prompt owners to take earlier action to resolve them, thereby improving their horse’s welfare.     

A cross-sectional study of geriatric horses in the United Kingdom. Part 1: Demographics and management practices

Reasons for performing study: With growing numbers of aged horses, geriatric medicine is becoming increasingly important in equine veterinary practice; however, there is a paucity of information on the UK equine geriatric population. Objectives: To describe the demographic characteristics of the equine geriatric population and to assess management practices undertaken by owners of geriatric horses (aged ≥15 years). Methods: A cross‐sectional study was conducted, surveying a randomly selected sample of veterinary registered owners with horses aged ≥15 years, using a self‐administered postal questionnaire. Results: Horses aged ≥15 years represented 29% of the equine population in the study area. The response rate to the questionnaire survey was 80.2%. Management practices were similar to those previously described for the general equine population. However, the level of exercise and feeding practices changed significantly with increasing age. A summary of the demographic characteristics, feeding and management of horses in a sample of the geriatric equine population is presented. Conclusions and potential relevance: The management of geriatric horses has a direct effect on their health and welfare and this study has provided valuable information on the demographics and management of geriatric horses and ponies in the UK. The information can be used to form targeted owner education programmes for geriatric health and should aid in the investigation and prevention of disease.     

The recognition of pain and learned behaviour in horses which buck

Bucking behaviour in horses is potentially dangerous to riders. There is limited information about how bucking behaviour should be investigated by veterinarians. The objectives of this article are to define bucking behaviour, to review the literature relating to bucking and allied behaviours in horses and describe personal observations and to describe an approach to clinical investigation and management strategies. A literature review from 2000 to 2020 was performed via search engines and additional free searches. A buck is an upward leap, usually in addition to forward propulsion, when either both hindlimbs or all four limbs are off the ground with the thoracolumbosacral region raised. Bucking often occurs as a series of such leaps and different manifestations include ‘pronking’, ‘bronking’ and ‘fly bucking’. Causes include excitement, exuberance, defensive behaviour associated with fear, learned behaviour through negative reinforcement or a reaction to musculoskeletal pain. Specific causes of pain include an ill-fitting saddle or girth, thoracolumbar pain, girth region pain, sternal or rib injury, neuropathic pain, sacroiliac joint region pain, referred pain and primary hindlimb lameness. Any of these may be compounded by a rider who is fearful, poorly balanced or crooked. Determination of the underlying cause requires a comprehensive clinical assessment, including assessment of saddle fit for horse and rider and suitability of the horse–rider combination. In some horses, identification of a primary source of pain allows targeted treatment and resolution of pain, but careful retraining is crucial. An understanding of learning behaviour is required for successful rehabilitation. It was concluded that identification of the cause of bucking may enable treatment of primary pain which, when combined with retraining, results in management of bucking behaviour. However, in a minority of horses, dangerous bucking behaviour cannot be reliably resolved, requiring retirement or euthanasia of the horse.     

Drug withdrawal times for performance horses and horses intended for food

To protect the health and welfare of horses, veterinarians must legitimately use therapeutic medications. Many drugs are appropriately used to treat various disease conditions of horses, yet many of them have the ability to affect athletic performance or leave residues in tissues. For performance horses, the primary reason to have drug rules is to ensure fair competition and to protect the welfare of the horses and riders. When medications are administered to horses intended for human consumption, it is the responsibility of the veterinarian to ensure that violative drug residues do not occur. If horses are to receive proper veterinary care, suitable information on drug detection times must be available to equine practitioners.     

The influence of rider:horse bodyweight ratio and rider-horse-saddle fit on equine gait and behaviour: A pilot study

The effect of rider weight on equine welfare and performance requires further investigation. The objective of this prospective, cross-over, randomised trial was to assess gait and behavioural responses of horses to riders of similar ability, but different bodyweights. Six nonlame horses in regular work were ridden by each of four riders: Light (L), Moderate (M), Heavy (H) and Very Heavy (VH). Saddle fit was assessed subjectively throughout the study. Each horse was ridden twice by riders L and M, and once by rider H. Rider VH rode five horses once and one twice. Each horse-rider combination undertook a standardised, 30-min ‘dressage-test' which was abandoned if we observed lameness grade ≥ 3/8 in one limb, grade ≥ 2/8 in ≥ 2 limbs, or ≥ 10/24 behavioural markers of pain. Horses were reassessed in hand 45–60 min after any abandonment. Mean rider bodyweights, body mass index (BMI) values and rider:horse bodyweight percentages for the L, M, H and VH riders were respectively: 60.8, 77.8, 91.0, 142.1 kg; 23.2, 28.0, 26.3, 46.9 kg/m²; 10.0–11.7%, 12.8–15.0%, 15.3–17.9%, 23.6–27.5%. All 13 H and VH rider tests (lameness, n = 12; behaviour, n = 1) and one of 12 M rider tests (lameness) were abandoned. Lameness was confirmed using inertial measurement unit data. All horses trotted sound after test abandonment and completed the study moving well when ridden. Limitations of the study were saddle fit was not ideal in all horse-rider combinations and abandonment criteria were subjective. The conclusions and clinical relevance of the study were that large riders can induce temporary lameness and behaviours consistent with musculoskeletal pain. This may relate to rider bodyweight and/or weight distribution. Riders M and H had similar BMI but markedly different test abandonment rates, therefore bodyweight is likely to be more relevant than BMI. Further work is required to determine if horse fitness, adaptation to heavier weights and better saddle fit for heavier/taller riders will increase horses' weight-carrying capacity.     

Cross-sectional survey of owner knowledge and husbandry practices, tack and health issues affecting working horses in Lesotho

Reasons for performing study: To establish baseline parameters of equine health, owner knowledge and husbandry practices and tack against which benefits to local horses arising from an equine charity's training programme in Lesotho could be measured. Objectives: To describe and investigate associations between owner knowledge and equine husbandry practices, horse health and tack‐related parameters prior to the start of the training programme. Methods: A cross‐sectional survey was undertaken in the catchment area of students attending the first training course. Owners from randomly selected villages were interviewed about horse care using a standardised, structured questionnaire, administered face to face in local language. Horses were clinically examined and tack assessed according to standardised protocols. Results: Clinical examinations were performed on 312 horses and 287 owners were interviewed. Owners had variable knowledge of equine husbandry and limited understanding of appropriate primary and preventive healthcare. Equine health problems identified included ecto‐ and endoparasite infestation, mouth lesions, overgrown and unbalanced feet and tack‐associated wounds. The majority of tack was in poor condition, dirty and ill‐fitting. With the exception of below‐average body condition score, no associations were found between key adverse horse‐related clinical findings and owners reporting their horse as being ‘unhealthy’. Conclusions: Working horses in Lesotho have a range of physical problems, many of which could be ameliorated through targeted owner education. With limited access to veterinary advice and scarce resources, improved availability of affordable local equine trade skills is key to improving equine health. Potential relevance: Findings could be used to inform and direct training programmes to maximise benefits to equine health and to serve as a baseline against which to monitor effects of educational and other interventions.     

Borrelia burgdorferi infections with special reference to horses. A review

This review discusses the literature on B. burgdorferi infections in view of the rising incidence of this infection in general and the increasing concerns of horse owners and equine practitioners. Lyme disease, the clinical expression of Borrelia infections in man is an important health problem. The geographic distribution of B. burgdorferi infections in equidae should resemble that of human cases because the vector tick involved, Ixodes ricinus, feeds on both species and, indeed, the infection has been established many times in horses. However, a definite diagnosis of the disease "Lyme borreliosis" in human beings as well as in horses and other animals is often difficult to accomplish. Although a broad spectrum of clinical signs has been attributed to B. burgdorferi infections in horses, indisputable cases of equine Lyme borreliosis are extremely rare so far, if they exist at all.     

Equine gestational length and location: is there more that the research could be telling us?

Clear definitions of ‘normal’ equine gestation length (GL) are elusive, with GL being subject to a considerable number of internal and external variables that have confounded interpretation and estimation of GL for over 50 years. Consequently, the mean GL of 340 days first established by Rossdale in 1967 for Thoroughbred horses in northern Europe continues to be the benchmark value referenced by veterinarians, breeders and researchers worldwide. Application of a 95% confidence limit to reported GL range values indicates a possible connection between geographic location and GL. Improved knowledge of this variable may help in assessing the degree of the neonate’s prematurity and dysmaturity at or soon after birth, and identification of conditions such as incomplete ossification of the carpal and tarsal bones. Associated pathologies such as bone malformation and fracture, angular limb deformity and degenerative joint disease can cause chronic unsoundness, rendering horses unsuitable for athletic purpose and shortening ridden careers. This review will examine both the factors contributing to GL variation and the published data to determine whether there is potential to refine our understanding of GL by establishing a more accurate and regionally relevant GL range based on a 95% confidence limit. This may benefit both equine industry economics and equine welfare by improving early identification of skeletally immature neonates, so that appropriate intervention may be considered.     

Helping working Equidae and their owners in developing countries: Monitoring and evaluation of evidence-based interventions

There are an estimated 112 million Equidae (horses, donkeys, mules) in the developing world, providing essential resources for their owners’ livelihoods and well-being. The impoverished situation of their owners and the often harsh conditions in which they work mean that the animals’ welfare is a cause for concern. A number of equine non-governmental organisations (NGOs) operate within working equid communities providing veterinary care, education and training programmes aimed at improving equine welfare. However, there is little published information available that describes monitoring and evaluation (M&E) of such interventions using objective outcome-based indicators and where baseline data are available. The aim of this paper is to summarise the peer-reviewed reports of M&E in this sector and identify the key issues which need to be addressed in ensuring that such evaluations provide useful information on the work of these organisations.A rigorous evidence base for designing future interventions will provide an opportunity for enhancing the effectiveness of working equid NGO operations. Increased availability of M&E reports in the peer-reviewed literature will enable NGOs to learn from one another and disseminate to a wider audience information on the role of working Equidae and the issues they face.