[question name="Lori"] I was wondering if, in addition to the various topics that you discussed as possible causes of equine seizures ("AAEP Answerline: Seizures" in the November 1999 issue of The Horse, online at TheHorse.com/10386), Cushing’s syndrome is a contributing factor. My gelding has the start of it, and exhibited an episode of shaking, colic, then a seizure. Is this part of Cushing’s?
Cushing’s and Seizures?
Could Cushing’s syndrome be a possible cause of seizures?
ACushing’s disease is caused by a tumor or hyperplasia of part of the pituitary gland. Sometimes the pituitary gland becomes enlarged, but often it is not physically enlarged, just producing larger amounts of hormones than usual. (A complete summary of Cushing’s is online at TheHorse.com/12534.)
Seizures are rare in the horse, and adult horses especially have a high seizure threshold. Cushing’s disease can cause seizures, but they are very rarely seen with this disease. It is hard to say for sure why some Cushing’s horses have seizures, but it might be from associated liver disease (sometimes seen with Cushing’s), hyperglycemia (high blood sugar, which is common in Cushing’s), or from the pituitary gland becoming enlarged with the tumor and compressing other structures of the brain (as mentioned above, not normally seen with Cushing’s). I have worked with a number of horses with Cushing’s, and none had seizures.