Last Updated on February 21, 2022 by Allison Price
Older horses continue to be plagued by the pituitary paras intermedia dysfunction (equine Cushing’s disease), PPID is the most common hormonal or endocrine disease affecting older horses. It affects about 20% of horses who are over 15. Thankfully, there is an FDA-approved treatment that treats PPID. It appears to be quite effective: Pergolide Mesylate.
If the disease is not controlled and treated promptly, there will be an excessive release of mediators and proteins. These potent mediators are then released from the hypothalamus’ damaged neurons. They also affect other brain regions that secrete an excess of hormones and mediators. This can cause serious damage to the horse’s health.
PPID can be characterized by lethargy, poor athleticism, reduced performance, muscle atrophy along with delayed shedding and excessive hair growth.
Pergolide can be given at a dose of 2 mg/kg daily to equine with PPID. The medication works by blocking the dopamine receptors in the hypothalamus, which reduces the production of hormones.
Pergolide’s FDA status is not a guarantee of its safety. However, there are still many questions about its inner workings (pharmacokinetics, pharmacodynamics). In a study*, pergolide was administered at 4 mg/kg body weight daily to horses diagnosed with PPID using the thyrotropin-releasing hormone stimulation test. The blood levels of pergolide in the horses was then measured. These were the key findings:
- Pergolide is fast in action, suppressing intermedia pars activity in just a few hours after oral administration.
- Horses don’t accumulate pergolide and stable levels are achieved within three days after starting treatment.
- Pergolide is quickly eliminated from the system with a half-life of less than 12 hours.
- Horses with PPID may find it more beneficial to take pergolide twice daily (i.e., split the total dose into morning and evening doses).
Horses with PPID often have poor hoof, skin, or coat health. To support these vital structures, you might consider offering BIO-Bloom PS ( Bio-Bloom HHF in Australia). Bio-Bloom PS is high in methionine and zinc and can be top-dressed with horse’s feed.
Pergolide is considered a controlled medication by some governing bodies. Horse owners should consult a veterinarian before using it in competition horses.
