What is Cushing’s Disease?
· An incurable, but manageable, progressive disorder common among aged and geriatric horses. Results in an over secretion of several hormones, primarily cortisol (stress hormone) from the pars intermedia (PPI) portion of the pituitary gland. For this reason, the official name is Equine Pars Pituitary Intermedia Disorder (PPID).
Clinical Signs
· Abnormal shedding/long haircoat
· Abnormal fat distribution
· Persistent sweating
· Laminitis
· Weight loss/muscle wasting (loss of topline)
Diagnosing The Disease
· Some horses can be diagnosed on clinical signs alone.
· In the early stages, blood testing can be used to determine course of disease and treatment
o Endogenous ACTH
§ Normal levels below 30 pg/mL, may not be elevated in early stages of disease and can be falsely high during laminitic episodes.
§ Natural increase during the fall season (September through October) so interpretation of ACTH should be done carefully.
Treatment
· Pergolide Mesylate: Prascend
Most effective at 1-3 mg by mouth once daily
Cost $2 to $6.75 daily
o May take 6-8 weeks to see clinical response and lifelong treatment is required
· Repeated blood testing every 6-12 months to monitor degree of hormonal control.