Horses diagnosed with pituitary pars intermedia dysfunction life expectancies

Horses diagnosed with pituitary pars intermedia dysfunction do not have shorter life expectancies but experience more medical events during their lifetime
Emma Stapley DVM, DACVIM , Caroline Gillespie-Harmon DVM, MS, DACVS, Sarah Waxman DVM, MS, DACVS, Amanda Farr DVM, DABVP, and François-René Bertin DVM, PhD, DACVIM XT

Abstract
Objective
The frequency of comorbidities in horses with pituitary pars intermedia dysfunction (PPID) in first-opinion practice is unknown. It is hypothesized that horses with PPID would have more frequent medical events and be euthanized at a younger age.

Methods
This was a case-control retrospective study. Medical records ranging from 1996 to 2024 including 132 horses diagnosed with PPID and 274 controls matched by age and breed were reviewed. Variables associated with PPID were evaluated with a Fisher exact or Mann-Whitney U test followed by conditional logistic regression. Results were reported as median (IQR) and percentage of total.

Results
Horses diagnosed with PPID were not euthanized at a younger age (median of 26 years [IQR, 22 to 31 years] vs median of 24 years [IQR, 21 to 29 years]). Factors independently associated with a diagnosis of PPID were poor healing, dental issues (including missing tooth or diagnosis of equine odontoclastic tooth resorption and hypercementosis), hyperinsulinemia-associated laminitis, and being prescribed NSAIDs.

Conclusions
The use of NSAIDs and occurrence of poor healing, hyperinsulinemia-associated laminitis, and dental issues were independently associated with a diagnosis of PPID.

Clinical Relevance
Horses diagnosed with PPID did not have shorter life expectancies but experienced more medical events during their lifetime compared to horses not diagnosed with PPID.