Equine Obesity Research Articles

The impact of restricted grazing systems on the behaviour and welfare of ponies.

Equine obesity is a growing concern. Much of the current management advice centres on dietary restrictions, including the removal or limitation of grazing. Little is known about the impact of these approaches on the welfare of the horse. This study investigates the effect of two commonly used grazing systems advocated for the control of weight-the 'strip-grazing' and the 'track' systems-on the behaviour and welfare of outdoor-living ponies. A within-subject cross-over experimental design with four groups of pasture-kept ponies experiencing each system for 4 weeks in a random order. Time budgets and behavioural indicators of welfare were measured using 24-h electronic surveillance, morphometric parameters including weight, body condition score and cresty neck score were measured weekly and activity levels were tracked. The effect of grazing system on movement and behaviour was tested using a general linear model. Ponies moved more [median (IQR) % time spent moving, track: 3.23% (2.08%), strip: 2.02% (0.90%); p = 0.001] and travelled a greater distance [median (IQR) metres/24 h, track: 7013.47 m (1761.49 m), strip: 5331.91 m (494.16 m); p < 0.001] and engaged in less overt agonistic behaviour on the track system compared with the strip system [median (IQR) prevalence per hour; track: 0.14 (0.30), strip: 0.21 (0.37) p = 0.02]. A relatively short time period of exposure to each grazing system. Ponies on strip systems moved less and exhibited increased agonistic interactions compared with the track system, maybe as a result of a perceived reduction in space or concentration of resources, although the accessible areas were matched. These results suggest that there may be physical as well as psychological health benefits to the track system.

Pesky Pudgy Ponies: Equine Obesity and the Behavior Consultant

Obesity is one of the most common, and also most preventable causes of poor welfare in leisure horses. Research to date has shown that leisure equestrians have a poor ability to visually distinguish between healthy and unhealthy weights for horses. Equine behavior consultants are well-placed to offer advice as they are generally called in when an owner has recognized some problem. Equine behavior consultants should consider investing in their education around recognizing obesity and ways it can be managed and addressed, to best serve their clients as part of the veterinary and behavior team.

Obesity and obesity-associated metabolic disease conditions in Connemara ponies in Ireland.

Equine obesity combined with insulin dysregulation (ID) is a major risk factor associated with laminitis. Some pony breeds appear to be at increased risk. However, little is known regarding the prevalence of obesity or hyperinsulinaemia as evidence of ID in Irish ponies. To investigate the prevalence of obesity and associated endocrine/metabolic disease conditions in Connemara ponies and to determine if hyperinsulinaemia in these ponies could be predicted by morphometric or metabolic markers. Cross-sectional study. The study population included registered Connemara ponies recruited through public and veterinary social media posts. Ponies underwent a physical examination and information on their management and clinical history was obtained via owner questionnaire. The body condition score (BCS) was measured using the Henneke system; cresty neck score (CNS) and regionalised adiposity were also assessed. Hyperinsulinaemia was confirmed by measuring serum basal insulin concentration (BIC) or insulin concentration after an oral sugar test (OST). Blood glucose and triglyceride concentrations were measured. Characteristics of hyperinsulinaemic and insulin-sensitive ponies were compared by logistic regression. Two hundred ponies were included; 59 ponies (29.5%) had a BCS ≥7, 58 (29.0%) had a CNS ≥2.5 and 135 (67.5%) had regionalised adiposity; 137 (68.5%) ponies had at least one of these abnormalities. Owner-reported history or clinical evidence of chronic laminitis was found in 92 ponies (46.0%). Hyperinsulinaemia was confirmed in 32 ponies (16.0%), including 23 of 91 (25.3%) detected by OST and 9 of 109 (8.3%) by BIC. Hypertriglyceridaemia was observed in 12 of 198 ponies (6.1%) ponies and hyperglycaemia in 11 of 197 ponies (5.6%) ponies. The odds of hyperinsulinaemia increased by a factor of 6.53 (95% confidence interval: 2.95, 15.21) when BCS was ≥7. The OST was not performed in all ponies. Increased adiposity, laminitis and metabolic derangements are prevalent in this native Irish pony breed.

Stakeholder perception of equine obesity

Stakeholder perception of equine obesity

Addressing equine obesity in showing using a behaviour change approach

Addressing equine obesity in showing using a behaviour change approach

A study on obesity and risk factors among leisure and polo horses in Kaduna State, Nigeria

Despite the growing concern about the impact of obesity on equine health, little information is available on equine obesity in Nigeria. The study aimed to determine the prevalence of obesity in leisure and polo horses as well as associated risk factors in Kaduna State, Nigeria. A cross-sectional study was carried out. A total of 116 horses were selected for the study, and the modified Henneke method (1–9 scale) was used to assess body condition scores, with animals having a score of ≥ 7 classified as obese. Information regarding age, breed, and sex was documented, while information regarding feeding and management was obtained from a structured questionnaire. Factors associated with obesity were assessed using logistic regression analysis. The overall prevalence of obesity in horses sampled was 12.1 % (14/116). The prevalence of obesity in leisure horses (21.4 %) was higher than in polo horses (3.3 %). Factors associated with increased odds of obesity were being a local breed of horse (18.6 %), being a stallion (21.4 %), horses not being exercised (66.7 %), horses tethered to a stake in the ground (23.2 %), and horses fed ad libitum on concentrates (21.4 %). Knowing the prevalence of obesity in this population and associated risk factors will enable optimal targeting of owner education regarding management strategies to reduce the prevalence of equine obesity, reducing the risk of conditions such as laminitis and insulin dysregulation.

Definition, Assessment, Health Consequences and Management of Equine Obesity: A Review

Abstract Obesity is a state of abnormal or excessive fat accumulation. Obesity in horses increases the risk of developing a variety of health issues such as: insulin dysregulation (ID), reduced athleticism, colic, abnormal reproductive performance, laminitis, endotoxaemia, diabetes mellitus, hyperlipaemia, impaired thermoregulation, pituitary pars intermedia dysfunction, and osteochondrosis. Obesity is a significant health and welfare issue in horses that may go unreported or unnoticed due to a caregiver’s (owner) neglect. Weight gain occurs when a horse’s energy consumption exceeds his or her physical energy needs. Obesity is best assessed via necropsy or upon in vivo assessment with deuterium oxide administration, although this is not feasible in a clinical environment. In practice, obesity is assessed by: body condition scoring, cresty neck scoring, ultrasono graphic assessment, morphometric measurements, or biochemical indicators in the blood. Dietary and exercise programs are the primary means of controlling equine obesity. Pharmacologic assistance (levothyroxine sodium and metformin hydrochloride), being a secondary approach, may be effective in some cases. Management involves a long-term plan that requires the horse’s caregiver’s effort and discipline, as well as the support and supervision of their veterinarian. This paper outlines the assessment, health consequences, and management of equine obesity.

91 Horse owners’ perspectives of horse weight management

Equine obesity is a significant welfare issue in developed countries. As the main decision-maker for horses, owners are at the forefront of horse welfare, yet limited research has assessed owners’ role in horse weight management. This study aimed to: 1) compare horse owner assessments of their horses’ weight with a veterinarian assessment and, 2) identify how horse owners understand their horses’ weight and implement weight management strategies in practice. An on-farm horse care questionnaire was administered to 76 horse owners in Prince Edward Island, Canada. Owners indicated whether they thought their horse(s) were underweight, healthy, or overweight. Owner and veterinarian perception of horse weight was compared using a 3-by-3 table and kappa statistics (n = 411 horses). Of the 76 owners, 24 owners of overweight horses were purposively sampled to participate in in-depth qualitative interviews. Interviews were transcribed and analyzed using template analysis, a qualitative research approach in which textual data are coded to identify patterns and develop overarching themes. There was fair agreement (kappa = 0.4) between the veterinarian's and owners’ weight assessment, but owners tended to underestimate (20%) versus overestimate (9%) their horses’ weight. Analysis of the in-depth interviews (a total of 24 h of conversation) revealed that horse owners discussed weight management in complex ways that incorporated aspects of their horses’welfare and background. Owners discussed trade-offs between managing horses in outdoor, group environments and maintaining their horse within a “healthy” weight. Further, emotional responses to managing under- versus overweight horses and societal norms influenced horse owners’ decisions toward managing their horses as slightly overweight compared with slightly underweight despite their belief that horses’ physical health is better when managed as slightly underweight. Owners took personal responsibility of weight management-related decisions for their horse(s) but sought knowledge from respected horse owners in their community. Owners constructed the veterinarians’ role as predominantly treatment-oriented and did not consider them resources for preventative care related to horse weight management. These findings suggest that owners place importance on managing their horses' weight yet face intrinsic and extrinsic barriers that require shifts in societal paradigms and enhancement of knowledge transfer. Emphasis for knowledge dissemination and translation may need to be placed on equestrian bodies outside of the veterinary community, given that horse owners consider their peers a primary knowledge source.

Impacts of Adiposity on Exercise Performance in Horses

There is ample research describing the increased risk of health concerns associated with equine obesity, including insulin dysregulation and laminitis. For athletes, the negative effect of weight carriage is well documented in racing thoroughbreds (i.e., handicapping with weight) and rider weight has been shown to impact the workload of ridden horses and to some degree their gait and movement. In many groups of competitive and athletic horses and ponies, obesity is still relatively common. Therefore, these animals not only are at risk of metabolic disease, but also must perform at a higher workload due to the weight of their adipose tissue. Excess body weight has been documented to affect gait quality, cause heat stress and is expected to hasten the incidence of arthritis development. Meanwhile, many equine event judges appear to favor the look of adiposity in competitive animals. This potentially rewards horses and ponies that are at higher risk of disease and reinforces the owner's decisions to keep their animals fat. This is a welfare concern for these animals and is of grave concern for the equine industry.

Gastro-Intestinal Microbiota in Equines and Its Role in Health and Disease: The Black Box Opens.

Horses are large non-ruminant herbivores and rely on microbial fermentation for energy, with more than half of their maintenance energy requirement coming from microbial fermentation occurring in their enlarged caecum and colon. To achieve that, the gastro-intestinal tract (GIT) of horses harbors a broad range of various microorganisms, differing in each GIT segment, which are essential for efficient utilization of feed, especially to use nutrients that are not or little degraded by endogenous enzymes. In addition, like in other animal species, the GIT microbiota is in permanent interplay with the host's cells and is involved in a lot of functions among which inflammation, immune homeostasis, and energy metabolism. As for other animals and humans, the horse gut microbiome is sensitive to diet, especially consumption of starch, fiber, and fat. Age, breeds, stress during competitions, transportation, and exercise may also impact the microbiome. Because of its size and its complexity, the equine GIT microbiota is prone to perturbations caused by external or internal stressors that may result in digestive diseases like gastric ulcer, diarrhea, colic, or colitis, and that are thought to be linked with systemic diseases like laminitis, equine metabolic syndrome or obesity. Thus, in this review we aim at understanding the common core microbiome -in terms of structure and function- in each segment of the GIT, as well as identifying potential microbial biomarkers of health or disease which are crucial to anticipate putative perturbations, optimize global practices and develop adapted nutritional strategies and personalized nutrition.

Exploring human behavior change in equine welfare: Insights from a COM-B analysis of the UK's equine obesity epidemic.

While equine obesity is understood by equine professionals to be a serious and widespread welfare problem, thus far approaches to reducing the prevalence of obesity in the UK's leisure horses have mainly been limited to educating owners about the dangers of obesity in their horses. In human health, approaches to behavior change encourage holistic thinking around human behavior, recognizing the importance of the connection between the individuals' knowledge, attitudes, habits, and the social and physical environments. This study used qualitative data from interviews with horse owners and professionals, open-access discussion fora and focus groups in order to collate extensive information about the factors shaping the UK's equine obesity crisis. The data were initially analyzed using a grounded theory method to determine the common themes, and were then analyzed using the COM-B model of behavior change, in order to identify areas where human behavior change might be better supported. The analysis highlighted the importance of a holistic approach to behavior change, since all areas of the COM-B were important in limiting owners' recognition of, and response to, equine obesity. For example, environments and social norms limited the likelihood of owners proactively managing horse weight, and owners also found it difficult to identify overweight horses, and evaluate the risks of long-term health issues as a result of weight, with short-term negative impacts of weight management. While interventions often aim to educate owners into changing their behavior, this analysis highlights the importance of creative and holistic approaches which work alongside the owners' motivations, while shaping the social and physical environments.

Are Horse Owners Able to Estimate Their Animals' Body Condition Score and Cresty Neck Score?

Simple SummaryObesity and overconditioning are becoming more prevalent in horses and could be the cause behind various diseases. Evaluation of body condition scores (BCS) and cresty neck scores (CNS) are important tools used to assess the risk of obesity, and owners and caretakers should be able to correctly evaluate their animals. The aim of this study was to compare the ability of owners to correctly assess the BCS and CNS of their animals, comparing them with the scores given by an experienced examiner. In our population, overconditioning was present in 29% and 24% of horses according to the owners and the vet, respectively, while obesity was detected by the owners and the vet in 2% and 1% of cases, respectively. Agreement between the owners and the vet was slight for both body condition score and cresty neck score, and it was influenced by age, breed, gender, and activity of the horse. Education of owners and caretakers to correctly assess their animals is important to prevent the development of obesity and overconditioning and related diseases.Obesity and overconditioning are becoming more prevalent in horses, and are influencing the animal’s health, activity, and reproductive efficiency. Body condition score (BCS) and cresty neck score (CNS) have been correlated with the development of various diseases. Many of the papers in the literature evaluate the prevalence of obesity and overconditioning in horse populations considering BCS given by owners. The aim of this study was to evaluate the validity of the owners’ estimation of the degree of equine obesity or overconditioning by comparing BCS and CNS provided by each owner and a board-certified vet to a cohort of 259 horses and their agreement based on age, breed, sex, and activity of the animals. Overconditioning was present in 29% and 24% of horses according to the owners and the vet, respectively, and obesity in 2% and 1%, respectively. Agreement between BCS and CNS given by the owners and the vet was slight, with owners scoring horses either lower or higher than the vet. Agreement between the owners and the vet assessment was also influenced by age, breed, sex, and activity of the animals. Education of owners and caretakers to correctly assess BCS and CNS and regular evaluation of the animals throughout the year is important to prevent the development of obesity and overconditioning and related diseases.

Equine obesity: Vet client communication

Equine obesity: Vet client communication

Fecal extract from obese horses induces an inflammatory response by murine macrophages in vitro.

To compare the inflammatory response of murine macrophages exposed to the enteric microbiome of obese horses versus nonobese horses. Fecal samples from 12 obese horses (body condition score ≥ 7/9) and 12 nonobese horses (body condition score 4 to 5/9) with similar dietary management. Fecal supernatant was prepared from frozen fecal samples. RAW 264.7 macrophage cells were exposed to the fecal extract. Inflammatory cytokine (interleukin-1β, tumor necrosis factor-α, and interleukin-6) gene expression was quantified via real-time quantitative reverse transcription PCR assay, and cytokine concentration was quantified via ELISA. Lipopolysaccharide was evaluated in fecal extract via chromo-limulus amoebocyte lysate assay. Compared with fecal extracts from nonobese horses, fecal extracts from obese horses presented higher concentrations of lipopolysaccharide and induced a heightened expression of the proinflammatory cytokines interleukin-1β, tumor necrosis factor-α, and interleukin-6 from macrophages. The increased levels of inflammatory markers induced in murine macrophages by the microbiome of obese horses in vitro suggested important differences in the enteric microbial composition of these horses, compared with nonobese horses. Overall, this study showed that the microbiome may play a role in mediating an inflammatory response within the gastrointestinal tract of obese horses. Mechanisms of obesity in the horse have not been fully elucidated. Improved understanding of the pathophysiology of disease will guide future research into potential diagnostic and therapeutic interventions for equine obesity.

Time for action on equine obesity

Time for action on equine obesity

Equine obesity and the role of the veterinary nurse

Equine obesity is defined as a medical disease in which excess body fat has accumulated to such an extent that it has an adverse effect on the general health of the horse. Obesity is a cause for concern, with one-third of the equine population in the UK being regarded as obese, although owner recognition of obesity in horses is an inherent problem, with many underestimating the body condition or weight of their horse. This is further complicated by the fact that with larger framed horses, or horses that are already overweight, assessing body condition is more difficult. There are a number of ways to assess body condition and the most practical means of regular assessment is body condition scoring, although this is regarded as subjective. As with many diseases and disorders, the cause of obesity is multifactorial. However, the most common reason for a horse to become obese is overfeeding, coupled with a lack of exercise. Obesity can be addressed with client education and veterinary nurses can provide advice on weight management programmes. However, these need to be tailored to the individual horse and owners need to recognise that they are entering into a long-term commitment.

Hidden in Plain Sight: Uncovering the Obesogenic Environment Surrounding the UK’s Leisure Horses

ABSTRACT Equine obesity is a major welfare concern in the UK, and the problem is thought to be increasing. Leisure horses are known to be most at risk of obesity, yet despite plenty of conjecture, the reasons for this are unknown. This study, therefore, aimed to establish the social and environmental factors which owners considered might contribute to levels of obesity in leisure horses in order to address the problem. This project used qualitative research methods to bring together data from interviews with 28 horse owners and 19 equine professionals, two focus groups, two years of field notes, and 17 threads from equine discussion fora. The data were analyzed using a grounded theory approach. This study determined that the environment around the UK’s leisure horses is “obesogenic”; that is, the environment is structured in numerous ways that make obesity a likely outcome. This is a result of multiple factors related to the changing relationships between humans and their horses in recent decades, which has led to horses being kept for their companionship rather than for their physical abilities as work or competition animals. In addition, commercial environments have been developed to cater for these leisure horses, including livery yards which often have inflexible rules and rich grasses, a heavily moralized feed and equine care industry, and lack of options for “safe” exercise. In these obesogenic environments, horse owners often find it difficult to make changes to their horses’ condition.

How human behaviour change science can help us manage obesity in horses

Equine obesity is one of the biggest welfare concerns facing our leisure horses today. As a preventable issue, with many serious consequences, obesity should be simple to fix (by reducing energy input and increasing exercise) – yet this issue remains one of the most complex and pervasive problems for the UK's horses. Despite many campaigns to raise awareness and improve owner education, levels of obesity in horses are thought to be as high as ever. In this article, we unpick some insights gained from the fields of psychology, sociology and human behaviour, which will help practitioners to find ways to buck the trend and encourage the equine community to manage horses' weight proactively.

Exploring horse owners' understanding of obese body condition and weight management in UK leisure horses.

Equine obesity is considered one of the most serious welfare concerns in UK leisure horses, yet little is known about how horse owners conceptualise their horse's weight as part of its health, or how they plan and carry out weight management. This study aimed to further our understanding of leisure horse owners' perceptions of equine health and awareness of excess fat in order to clarify our understanding of successful strategies for managing equine weight. This study used a qualitative research methodology. Data comprised 16 threads from online UK equine discussion fora, 28 individual interviews with leisure horse owners, 19 interviews with equine professionals such as vets and nutritionists, and two focus groups with a further 21 horse owners. Data were anonymised and analysed using a grounded theory approach. Awareness of excess fat was a complex issue, with owners finding it difficult to differentiate equine obesity from the shape they thought the horse was "meant to be", particularly if the horse was a heavier breed such as a native pony or cob. Owners were not necessarily "aware" or "unaware" of fat, but instead equine body fat was constructed as an integral part of the equine body. For example, owners might say that they thought their horse was an ideal weight yet describe their horse's overall body shape as "like a Thelwell". When owners became aware of fat as a changeable part of the horse's body, and/or a threat to health, the presence of fat was articulated as a strong-willed adversary, and weight management was considered a "battle" or "war". Owners found weight management difficult because they perceived that it had immediate negative welfare implications for the horse, and this therefore interfered with their preferred ownership practices and the horse-human relationship. Interview data are self-reported, and people may not always do what they say they do. This study has provided valuable insight into how owners conceptualise weight and weight management, yielding important information about communicating with owners about weight, tailoring weight management strategies, and promoting positive welfare.

Equine metabolic syndrome: evolution of understanding over two decades: a personal perspective

There has been a marked increase in the incidence of equine obesity globally, especially in countries where there has been a shift away from the horse having an economically essential working role. This change in its core role, plus the increasing numbers of individual horse owners without access to traditional knowledge of animal and land management, have helped fuel this equine obesity ‘epidemic’. Other important potential contributory factors include increased availability of good grazing and/or forage, as well as supplementary feeds. Obesity now presents a major welfare issue for horses and ponies, not only because of the direct weight-associated effects, but also due to the increased risk it poses for certain clinical conditions, in particular laminitis. For many owners and veterinarians, obesity and the equine metabolic syndrome are synonymous, but this is not necessarily the case. Furthermore, as we understand more about this syndrome and the causes of endocrinopathic laminitis, the emphasis has shifted from tissue or peripheral insulin resistance to insulin dysregulation. The present paper outlines how our knowledge of equine metabolic syndrome arose and continues to develop, as well as the authors’ personal involvement in some of these advances.