Case-control study of risk factors for pasture-and endocrinopathy-associated laminitis in North American horses

Abstract

OBJECTIVE To investigate risk factors for the development of pasture- and endocrinopathy-associated laminitis (PEAL) in horses and ponies in North America. DESIGN Case-control study. ANIMALS 199 horses with incident cases of PEAL and 351 horses from 2 control populations (healthy horses [n = 198] and horses with lameness not caused by laminitis [153]) that were evaluated in North America between January 2012 and December 2015 by veterinarian members of the American Association of Equine Practitioners. PROCEDURES North American members of the American Association of Equine Practitioners were contacted to participate in the study, and participating veterinarians provided historical data on incident cases of PEAL, each matched with a healthy control and a lameness control. Conditional logistic regression analysis was used to compare data on PEAL-affected horses with data on horses from each set of controls. RESULTS Horses with an obese body condition (ie, body condition score ≥ 7), generalized or regional adiposity (alone or in combination), preexisting endocrinopathy, or recent (within 30 days) glucocorticoid administration had increased odds of developing PEAL, compared with horses that did not have these findings. CONCLUSIONS AND CLINICAL RELEVANCE The present study identified several risk factors for PEAL that may assist not only in managing and preventing this form of laminitis, but also in guiding future research into its pathogenesis.

Incidence and risk factors for recurrence of endocrinopathic laminitis in horses

“…Prospective (longitudinal) cohort studies of laminitis are uncommon, but 2 recently completed prospective studies of disease incidence confirmed the importance of endocrinopathies and hyperinsulinemia in laminitis occurrence. It is important to note that the current study was not designed to evaluate the incidence of endocrinopathic laminitis.…”

“…A relationship between season and the incidence of laminitis has been described previously, with most studies indicating that spring and summer are associated with the greatest risk of disease . Also, the greatest proportion of cases in the current cohort of animals occurred in spring .…”

“…There is insufficient epidemiological data on endocrinopathic laminitis . Currently, due to a lack of dedicated studies, the rate of recurrence of endocrinopathic laminitis is poorly defined.…”

Phenotypic, hormonal, and clinical characteristics of equine endocrinopathic laminitis

“…Of these endocrinopathies, EMS was the most prevalent underlying disease occurring in 82% of cases, whereas PPID was present in ~38% of the animals. Unsurprisingly then, both generalized and regionalized adiposity were evident in the cohort, with the findings of increased BCS and CNS consistent with the use of these phenotypic markers in the diagnosis of EMS, and with a recent study that found increased adiposity to be a risk factor for endocrinopathic laminitis . These data are important as recognition of an underlying endocrinopathy might enable the timely implementation of management (EMS) or treatment (PPID) strategies.…”

“…Endocrinopathic laminitis is associated with hyperinsulinemia and is a frequent sequelae to 2 common equine endocrinopathies: equine metabolic syndrome (EMS) and pituitary pars intermedia dysfunction (PPID) . Increased adiposity (generalized or regional, or both) is also a risk factor for the disease . Pasture‐associated cases of laminitis are associated with hyperinsulinemia (without any accompanying signs of inflammatory processes, such as diarrhea) and therefore are also likely to often fall under the umbrella of endocrinopathic laminitis …”