Management of pituitary pars intermedia dysfunction in practice: A clinical audit.

ABSTRACT

In horses/ponies with pituitary pars intermedia dysfunction (PPID), pergolide mesylate treatment, with monitoring of therapeutic response, is recommended by contemporaneous literature and equine endocrinologists. However, it is unknown whether these recommendations are adhered to in private practice. This clinical audit aimed to compare treatment and monitoring of PPID cases in veterinary practice against available recommendations. Case data and basal plasma adrenocorticotropic hormone (ACTH) concentrations from all equids tested for PPID between 2012 and 2016 from a single veterinary practice in the UK were obtained. Records were reviewed and information on treatment and monitoring over the subsequent 2-6 years was extracted and compared with published recommendations. After exclusions, the audit population was 480 animals (median age, 20 years). The most common presenting signs were laminitis and/or historical laminitis (51.2%) and hypertrichosis and/or delayed coat shedding (24.5%). Based on seasonally adjusted reference intervals for basal ACTH concentration, 51.7% (n = 248) of animals were classified as positive, 37.1% (n = 178) as negative and 11.3% (n = 54) as equivocal for PPID. Records were available for 459 animals; of which pergolide treatment was initiated in 78.7% (n = 185/235) of positive cases, 19.2% (n = 10/52) of equivocal cases and 6.4% (n = 11/172) of cases classified as negative. Overall, 87.2% (n = 129/148) of cases commenced treatment as per recommendations. Only 77.7% (n = 160/206) of pergolide-treated animals had documented PPID monitoring and of these, only 48.1% (n = 77/160) had follow-up basal ACTH testing in the first 1-3 months following diagnosis. The findings confirm that management of PPID in veterinary practice fell below contemporaneous recommendations, especially for monitoring.