Five mg of Prascend (or more) for a horse with PPID seems extreme, doesn’t it?

The recommended dosage of pergolide is 0.002 mg (2 µg) per kilogram of body weight, once daily. For a 500-kilogram horse, this equates to one milligram tablet. Therefore, with a five-milligram dose, the horse would literally receive five tablets. This is already a substantial amount, but what if the horse still does not respond adequately to the medication?

Individual variation

In these exceptional cases, some veterinarians do not base their treatment solely on the recommended dosage but rather on the individual horse’s condition. They argue that the correct dosage is the one that normalises ACTH levels, even if it exceeds the manufacturer’s maximum recommended dose.

Finally, like all animals, horses exhibit significant physiological variation. A dosage that works well for one horse may not be equally effective for another. The manufacturer sets the maximum dosage based on average cases. While it is indeed exceptional, there may be horses that require this extremely high dosage.

Monitoring

If side effects and treatment efficacy are closely monitored and the dosage is adjusted downwards as soon as possible, there is no inherent harm in administering with such a high dose. There is no definitive threshold at which pergolide will always be effective. Moreover, the Prascend package insert recommends monitoring even before reaching the limit of five pills. Furthermore, there is no evidence of adverse effects on tissues (particularly nerves and the pituitary gland) with long-term use of high doses. There is also no clinical experience with other or more severe side effects at such high doses.

Do not experiment with dosage

It goes without saying that you should never adjust the dosage without consulting your veterinarian. Together, you have a greater knowledge and understanding than either of you alone. You know your horse and see the effects of the treatment daily. Your veterinarian not only has the clinical experience to compare your horse to other cases but also the specialised knowledge of medication and how to use it safely and effectively.

So, now you want to know everything about PPID?

Get access to even more science-based knowledge, insights and advice on PPID in general and treatment options in particular. Read ‘The PPID Book‘.