Hormonal, clinical, and survival outcomes in horses and ponies diagnosed with pituitary pars intermedia dysfunction...

Variables associated with hormonal, clinical, and survival outcomes of equids with pituitary pars intermedia dysfunction (PPID) are incompletely investigated.

Evaluate the effect of initial hormone concentrations, clinical signs, treatment, and owner-related variables on outcomes in horses and ponies with PPID.

Medical records from 213 horses and ponies diagnosed with PPID by 2 university-based primary care practices.

Analytical observational cohort study. Variables associated with adrenocorticotropic hormone normalization, clinical improvement, and survival after diagnosis were assessed with Fisher's exact tests or Mann-Whitney U tests. Stepwise backward multivariable logistic regression models were performed to determine variables independently associated with outcomes of interest with report of odds ratios (ORs) and 95% CIs.

Age at diagnosis (OR: 0.90 [95% CI, 0.84-0.97]; P = .003) and number of months between tests (OR: 0.96 [95% CI, 0.92-0.99]; P = .003) were associated with hormonal normalization after diagnosis. A body condition score (BCS) between 4 and 6/9 at diagnosis (OR: 15.07 [95% CI, 2.17-238.5]; P = .004) and median household income in the county of residence/1000 (MHI, OR: 1.17 [95% CI, 1.02-1.42]; P = .02) were associated with clinical improvement after diagnosis. Age at diagnosis (OR: 0.91 [95% CI, 0.85-0.98]; P = .01) and MHI (OR: 1.04 [95% CI, 1.01-1.07]; P = .02) were associated with survival after diagnosis.

Diagnosis at a younger age, frequent monitoring, a healthy BCS, and the owner's financial means were associated with improved outcomes in horses managed for PPID.