Nutritional Considerations When Dealing with an Obese Adult Equine

Owner-reported health and disease in U.S. senior horses

BACKGROUND

Information on health care and health status of U.S. senior horses (≥15 years of age) is currently sparse.

OBJECTIVES

(A) Provide an overview of owner-reported (1) medical conditions, (2) management/treatment practices for equine metabolic syndrome and pituitary pars intermedia dysfunction (PPID), (3) frequencies of routine health care practices and (4) supplement and pharmaceutical use in U.S. senior horses (≥15 years of age). (B) Evaluate potential risk factors for certain medical conditions and for low routine health care.

STUDY DESIGN

Online survey.

METHODS

Descriptive and inferential analysis (binomial logistic regression and ANOVA) of 2717 questionnaires from owners of U.S. senior horses.

RESULTS

The most common owner-reported veterinary-diagnosed medical conditions were osteoarthritis (30%), dental disorders (15%), lameness (14%), PPID (12%) and ocular disorders (6%). Advancing age was found to be a risk factor for PPID (odds ratio [OR] [95% confidence interval, CI] = 1.14 [1.10-1.18]), dental (OR [95% CI] = 1.18 [1.15-1.22]) and ocular (OR [95% CI] = 1.05 [1.01-1.10]) disorders. Only 36% of horses were free of owner-reported veterinary-diagnosed medical conditions at the time of the survey. During the year prior to the survey, most routine healthcare practices (i.e., veterinary health care, dental care and anthelmintic treatment) were typically undertaken one to two times per year, while farrier visits occurred mostly every 5-6 weeks. Retired senior horses had a higher risk of no health care visits (OR [95% CI] = 2.1 [1.38-3.06]), no dental care (OR [95% CI] = 2.0 [1.31-3.00]) and low farrier attendance (i.e., ≤4 times/year) (OR [95% CI] = 2.4 [1.57-3.63]) compared with senior horses used for pleasure riding. The most frequently administered drug was firocoxib (18%) and joint supplements were the most provided supplements (41%).

MAIN LIMITATIONS

Potential recall, response and sampling bias. Risk factor analyses do not establish causal relationships.

CONCLUSIONS

Medical conditions are highly prevalent in U.S. senior horses. Retired senior horses have an increased risk of low routine health care.

Tracking the Track: The Impact of Different Grazing Strategies on Managing Equine Obesity

Horses evolved to live in herds, continuously moving and foraging. Domestic horses often have limited social contact and movement, with high calorific intake, contributing to obesity. "Track grazing" is an increasingly popular management system, but evidence of its impact on weight management, behaviour, and welfare is limited. Horses (n = 19) resident at HorseWorld (UK) were observed July to October 2023, monitoring bodyweight (kg), Body Conditions Score (BCS), hoof health, behaviour, and welfare indicators. Horses on track grazing systems lost significantly more bodyweight (kg) (F(1,15) = 8.752, p = 0.010) than their restricted grazing counterparts, although this was not supported by BCS findings which may be ineffective for subtle body weight changes. Horses on track grazing systems lost (mean ± S.D.) 10.67 ± 9.9 kg from their starting weight, whereas those on the traditional paddock systems gained 6.8 ± 13.7 kg. Hoof health and general welfare assessment scores were maintained. More behaviours in "positive", "negative", and "neutral" categories were observed in paddock system horses than those on the track grazing system, although these differences were not statistically significant. These findings suggest that horses prone to bodyweight gain can be managed effectively using track grazing systems whilst maintaining health and welfare.

Prevalence of insulin dysregulation in the non-obese stock-type horse and relationship with morphometric neck measurements

Insulin dysregulation (ID), core to equine metabolic syndrome, may present without obesity. Testing for ID risk is commonly based on breed and obese phenotype but might be valuable for non-obese stock-type horses. This study aimed to determine the prevalence of ID in non-obese stock-type horses and evaluate if morphometric neck measurements (MNM) correlate with ID. Sixty-two, non-obese (BCS 5, range 2.5-6/9) stock-type horses were assessed for MNM: neck circumference at 25%, 50% (NC50), and 75% (NC75) length, and crest height. An oral sugar test (OST; 0.15 mL/kg BW corn syrup) was performed with blood taken pre- and 60 min post-OST for insulin (PREI, POSTI) and glucose (PREG, POSTG). Insulin dysregulation was defined as insulin concentration > 45 µIU/mL POSTI. Three of 62 horses were ID (4.8%; 95% CI 1.0%-13.5%). Horses with ID had greater PREG (121.0 ± 7.56 vs. 105.3 ± 1.72 mg/dL; LS means ± SEM; P = 0.04) and PREI (15.7 ± 2.63 vs. 10.5 ± 0.59 µIU/mL; P = 0.05) than normal responders. Mares had greater PREI than geldings (11.7 ± 0.76 vs. 9.4 ± 0.89 µIU/mL; P = 0.04). Stepwise regression indicated a weak relationship with crest height and POSTG (y = 51.27 + (0.88 x NC50); R2 = 0.09; P = 0.02). Post-glucose correlated with NC50 (r = 0.30; P = 0.04) and NC75 (r = 0.29; P = 0.03). This study showed 4.8% of non-obese horses had ID, warranting testing irrespective of phenotype, but only a weak association between MNM and POSTG was found.

Confidence does not mediate a relationship between owner experience and likelihood of using weight management approaches for native ponies

Native ponies are at increased risk of obesity and metabolic perturbations, such as insulin dysregulation (ID), a key risk factor for endocrinopathic laminitis. Management and feeding practices can be adapted to maintain healthy body condition and support metabolic health, but owners may inadvertently provide their ponies with inappropriate management leading to obesity and exacerbating risk of metabolic disease. Adoption of preventative weight management approaches (WMAs), including regular monitoring of body condition, providing appropriate preserved forage, promoting seasonal weight loss, and using exercise accordingly, are key in supporting native ponies' metabolic health. The factors influencing the adoption of WMAs, such as owners' experience and confidence, require exploration. The aim of the current study was to understand factors influencing owners' likelihood to undertake certain WMAs, to develop our understanding of suitable intervention targets. A total of 571 responses to an online cross-sectional questionnaire were analysed. Mediation analysis revealed that whilst long term (≥20 years) experience caring for native ponies was associated with owners increased, self-reported confidence in identifying disease and managing their native ponies, this did not translate to an increased likelihood of implementing WMAs. Conversely, respondents who managed ponies with dietary requirements related to obesity, laminitis, or equine metabolic syndrome were more likely to use WMAs related to feeding, seasonal weight management and exercise. Owner confidence was assessed and rejected as a mediator of the relationship between experience and WMA use. These results highlight the need for further work that elucidates the pathways leading owners to undertake action against obesity without the need for ponies to develop overt disease, as well as suggesting a need for long term managers of native ponies to update management practices with preventative care as the focus.

Where Are We Now? Feeds, Feeding Systems and Current Knowledge of UK Horse Owners When Feeding Haylage to Their Horses

Despite our improved understanding of equid digestive health and accurate rations formulations, obesity in the UK horse population remains high. Study aims: (1) to determine how owners are feeding their horses and what influences their choices, (2) to understand owners' knowledge of haylage and (3) to identify key areas that require additional education. Data were collected in 2020 from 1338 UK horse owners via two online surveys. Survey 1 was on general feeding practices, and Survey 2 was specifically on the feeding of haylage. Data were processed using chi square analyses + Bonferroni tests, with a significance p < 0.05. Equal numbers of leisure and performance horse owners completed both surveys. For Survey 1, 67% fed hay as the only forage, 30% fed forage (hay/haylage) + balancer, 36% fed haylage and hay to manage energy intake, 84% added a cube or coarse mix, 88% did not do forage analyses, 74% did not see the need for it and 16% did not know analyses could be done. In Survey 2, those who were not feeding haylage, 66% were not sure how to feed it, 68% worried about aerobic spoilage and 79% said the bale size was unsuitable. Body weight measurements (Survey 1 and Survey 2) were rarely performed (11%). Aspects of ration formulations, the value of feed analyses and how to interchange hay and haylage require additional education to owners for improved ration compilation.

Body Condition Score in Danish Horses Related to Type, Use, and Training Level: Patterns, Risk, and Protective Factors

Body condition in horses is a growing concern that has different patterns of development in horses that are above and below the ideal range. This study used professional and para-professional evaluators (veterinarians, farriers, trainers, Danish Equestrian Federation (DEF) officials) who were trained and certified in the use of a modified Henneke scoring system to assign a body condition score (BCS) on a scale of 1–9. Scores of 5–6 are regarded as ideal, and 78.6% of the evaluated horses were in these groups. Only 4.8% of horses were below ideal BCS but 16.5% were above ideal BCS, and this was influenced by type, age, and training. A significant protective effect towards above ideal BCS was shown for horses trained at higher intensities. Cold-blooded horses and traditional ponies had increased risk for being above ideal BCS. Although BCS increased with age, a large proportion of geriatric horses were both above and below ideal BCS. Discipline was not related to BCS. Patterns of BCS distribution for horses attended by different professionals were investigated. Veterinarians attended more horses with BCS above and below ideal values, farriers mostly saw horses that were above ideal BCS, and officials at competitions mainly saw horses with ideal BCS.

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

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.