Hi Lynne -
Welcome to the group, and thank you for your interest in this horse.
The alfalfa may or may not be an issue. What is the issue is that this horse is responding to the seasonal rise of ACTH - the main hormone involved with PPID. ACTH rises in all equines starting late summer/early fall, to prepare them for the winter months ahead. In PPID horses, that rise may be excessive, and it often shows up as laminitis in the time frame you mention.
This horse may be doing well on pergolide the rest of the year, but definitely needs an adjustment upward in dose starting in the summer. Many times it may 3-4 times the amount that is needed in spring/summer...sometimes even more.
To help you understand this issue better, you may want to review our educational website, and then if something "hits" you, provide that info the owner. Ten years is a long time for a horse to deal with seasonal rise laminitis, when it's usually preventable with correct pergolide doses.
Please ask any questions that may help you help this owner...
EC Primary Response