This is a difficult question to answer because we just don't have the knowledge to do it.

The dramatic rise may be because his loss of dopaminergic neurons has reached a critical level - or it may be because your pergolide is not up to potency.

We don't know what would happen if a horse on pergolide controlled the rest of the year was allowed to just weather out the seasonal rise with no dosage adjustment when good IR management of exercise and diet is in place, as it is with Lad.  We do know though that allowing ACTH to get out of control makes it more difficult to rein it back in again.  We also know that diet and exercise alone might not be enough to prevent  laminitis in the face of a high ACTH.

Since he's totally asymptomatic though, what you might try is putting him on 2 weeks of Prascend at 5 mg then retesting.  If there is a dramatic difference, your pergolide is the problem.

If you are already on Prascend, I would be inclined to titrate your dose up even though you have no symptoms. If you don't, the first symptom you get is likely to be laminitis.

Eleanor in PA
www.drkellon.com
EC Co-owner
Feb 2001