Related Experiment Video
Updated: May 5, 2026
08:31
Place and Response Learning in the Open-field Tower Maze
Published on: October 28, 2015
10.4K
Long-Term Response of Equids With Pituitary Pars Intermedia Dysfunction to Treatment With Pergolide
Harold C Schott1, Julie R Strachota1, Judith V Marteniuk1
1Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA.
Journal of Veterinary Internal Medicine
|May 3, 2025
Summary
Long-term pergolide treatment for pituitary pars intermedia dysfunction (PPID) in equids shows sustained clinical improvement in most animals. Some equids achieve normalized endocrine results, and many respond well to the initial pergolide dose.
Area of Science:
- Equine endocrinology
- Veterinary pharmacology
- Longitudinal clinical studies
Background:
- Pituitary pars intermedia dysfunction (PPID) is a common endocrine disorder in equids.
- Limited data exists on the long-term efficacy and safety of pergolide for PPID in horses and ponies.
Purpose of the Study:
- To evaluate the long-term clinical response, medical issues, and owner satisfaction in equids with PPID treated with pergolide over 14 years.
- To assess the impact of pergolide dosage on treatment outcomes in PPID-affected equids.
Main Methods:
- Thirty client-owned equids diagnosed with PPID were enrolled in an extended treatment study following an initial efficacy trial.
- Horses and ponies received either 2 μg/kg or 4 μg/kg of pergolide orally every 24 hours.
- Regular clinical re-evaluations and owner interviews were conducted over a 14.5-year period.
Main Results:
- The median survival time for treated equids was 3.6 years, with 24 of 30 animals euthanized during the study.
- Sustained clinical improvement was reported in 13 surviving equids after 5.5 years, with normalized endocrine test results in 75% at this time point.
- Long-term endocrine normalization varied, with only two of six surviving equids showing normal results after 9.5 years.
Conclusions:
- Long-term pergolide treatment effectively manages PPID in equids, leading to clinical improvement in nearly all cases.
- While some equids experience normalized endocrine function, this is not universal long-term.
- The study suggests that many equids can achieve favorable long-term responses with their initial pergolide dosage, without requiring dose escalation.
