Association Between Adrenocorticotropic Hormone Concentration and Clinical Signs of Pituitary Pars Intermedia Dysfunction in Swiss and Austrian Equids.
Authors: Fouché Nathalie, Doras Camille, Schüpbach-Regula Gertraud, Scherer Alexandre, Freudenschuss Barbara, Gerber Vinzenz
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary Pituitary pars intermedia dysfunction (PPID) remains challenging to diagnose in its earlier stages, partly because the relationship between clinical presentation and plasma ACTH concentration—the primary diagnostic marker—hasn't been well characterised. This Swiss and Austrian study examined 280 equids with suspected PPID during autumn months, using detailed clinical examinations and online veterinary questionnaires to correlate specific clinical signs with measured ACTH concentrations. Advanced PPID features (abnormal hair coat, laminitis, and supraorbital fat deposits) were significantly associated with elevated ACTH, alongside a metabolic syndrome phenotype that also linked to higher hormone levels, though notably these associations were strongest in older animals. The research revealed that early-stage clinical presentations clustered distinctly from advanced disease in statistical analysis, suggesting that the clinical signs we currently rely upon may miss PPID in its initial progression. These findings highlight a concerning diagnostic gap: practitioners may need to suspect PPID and recommend testing in cases showing equine metabolic syndrome features alone, even when classical PPID signs remain absent, whilst the profession should prioritise development of more sensitive biomarkers to enable earlier intervention.
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Practical Takeaways
- •Advanced clinical signs (hair coat changes, laminitis, supraorbital fat) should prompt ACTH testing; however, absence of these signs does not rule out early PPID—more sensitive diagnostic biomarkers are needed.
- •Equids presenting with metabolic syndrome features alongside elevated ACTH require early intervention; the association suggests these phenotypes share underlying endocrine dysfunction.
- •Clinical assessment should evaluate sign combinations rather than isolated findings, as aggregated clinical patterns better predict high ACTH concentrations than individual observations.
Key Findings
- •Hair coat abnormalities, laminitis, and supraorbital fat were univariably associated with high ACTH concentrations in 280 equids with suspected PPID.
- •Multiple correspondence analysis identified three distinct clinical phenotypes: equine metabolic syndrome, early-stage PPID, and advanced PPID.
- •Advanced PPID phenotype and metabolic syndrome phenotype were both significantly associated with elevated ACTH levels, but early-stage PPID clinical signs were not.
- •Age and specific clinical sign combinations were stronger predictors of high ACTH than individual signs alone, suggesting composite clinical assessment improves diagnostic inference.