A retrospective study of laminitis was carried out to identify risk factors associated with this disease on an East Anglian farm with approximately 1000 animals living in an area of 1000 acres. Medical records between January 1997 and May 2000 and between April 2005 and March 2008 were reviewed, and the age, sex, weight (kg), height (inches [in] and hands [H]) and weight‐to‐height ratio (kg/in) was recorded. The prevalence, incidence and seasonality of laminitis were determined and their relationship to the monthly temperature, rainfall and hours of sunshine was evaluated. Averaged over the six years, the highest prevalence (2.6 per cent) and incidence (16 cases/1000 animals) of laminitis occurred in May. The findings of a multivariate analysis revealed that females (P=0.007, odds ratio [OR] 1.46, 95 per cent confidence interval [CI] 1.1053 to 1.9646) and light animals (P≤0.001, OR=0.995, 95 per cent CI =0.9932 to 0.9963) had the greatest risk of developing laminitis. A positive association was found between hours of sunshine and incidence (P=0.007, relative risk [RR] 1.009, 95 per cent CI 1.001 to 1.012) and prevalence (P=0.002, RR 1.008, 95 per cent CI 1.003 to 1.012) of laminitis. The data suggest that there is a relationship between season, sex of the animal and the development of laminitis.

Background: Quantifying risk factors for laminitis development requires improvement. Objectives: To identify the most useful physical examination, metabolic and management factors to predict laminitis development in client‐owned, nonlaminitic ponies. Study design: Prospective cohort study. Methods: Physical examination, metabolic and management data were collected from a pony cohort 6 monthly for up to 4 years. Ponies were monitored for the development of laminitis. Metabolic data included basal plasma concentrations of ACTH ([ACTH]), adiponectin ([adiponectin]), triglycerides and glucose. Serum insulin concentrations ([insulin]) were measured in the unfasted basal state ([insulin]T0) and 60 minutes ([insulin]T60) after administration of corn syrup (0.3ml/kg). Separate multivariable Cox proportional‐hazards models were developed for physical, management/signalment and metabolic data and later combined into two final models. Low‐, medium‐ and high‐laminitis risk categories were defined based on basal or T60 [insulin]. Results: Overall, 374 ponies (age 5‐32 years) and 891 pony‐years were included in the main analysis. Laminitis incidence (95% confidence interval (CI)) was 4.8 (3.5‐6.5) cases/100 pony‐years. Laminitis development was associated with numerous univariable factors. Significant ( P < .05) factors retained in the final multivariable models included [insulin]T0, [insulin]T60, [adiponectin] and divergent hoof growth. [ACTH] was not independently associated with laminitis. Based on [Insulin]T0, low‐ (45.2 µIU/ml) categories encompassed 70, 20 and 10% of the population and had estimated 4‐year laminitis incidences (95%CI) of 6 (2‐9)%, 22 (10‐33)% and 69 (48‐82)% respectively. Based on [Insulin]T60 the low‐ (<53.4 µIU/ml), medium‐ (53.4‐153 µIU/ml) and high‐risk (≥153 µIU/ml) categories comprised 60, 30 and 10% of the population and had estimated 4‐year laminitis incidences (95%CI) of 3 (0‐6)%, 20 (10‐29)% and 73 (52‐84)% respectively. Main limitations: Results may not apply to different insulin assays, geographical regions, breeds or management types. Conclusions: [Insulin]T0 or [insulin]T60 best quantify the risk of future laminitis development in nonlaminitic ponies.