Horses with PPID have documented lower bone mineral density of non-weight-bearing lumbar vertebrae in the back. Researchers came to this conclusion in a 2021 study. PPID stands for pituitary pars intermedia dysfunction. Cushing’s disease in another name for PPID.

That study was titled, “Lumbar vertebral bone density is decreased in aged horses with pituitary pars intermedia dysfunction.”

This research was initially presented at the 2021 ACVIM Forum. It was also presented in 2023 at the 5th Global Equine Endocrine Symposium (GEES), brought to you by Boehringer Ingelheim.

Authors of this research were A.C. Colbath, J.S. Fortin, C. Panek, F.B. Vergara-Hernandez, T.N. Johnson, C.M. Burglass, C.A. Robison, A.A. Logan, N.A. Nelson, B.D. Nielsen, H.C. Schott II.

Horses With PPID Research Results

Following euthanasia, the lumbar spine was removed from seven aged (29 ± 6 years) horses with hypertrichosis (excess hair growth) and thyrotropin (TRH) stimulation test results supportive of pituitary pars intermedia dysfunction. It was also removed in six aged horses (26 ± 5 years) without hypertrichosis and nonsupportive TRH stimulation test results.

Computed tomographic (CT) scans were performed. The images were used for study and measurement.

Body mineral density of the lumbar spine was lower in PPID-positive than PPID-negative horses.

“In conclusion, these data support a loss of bone mineral density in horses with PPID that could make PPID-affected horses at increased risk of fracture, especially of non-weight-bearing bones.”

Owners of aged horses with pituitary pars intermedia dysfunction horses should be aware of this issue and discuss the ramifications with their veterinarians.

Further Reading

  • Kimberly S. Brown
    Kimberly S. Brown is an award-winning writer and publisher. She is the Editorial Director for My Senior Horse. Brown spent 10 years at Equine Network, parent company of My Senior Horse. Prior to that she worked for three years in equine nutrition after she retired from nearly 30 years working at The Blood-Horse. Brown spent the last 15 years of her time at that organization creating and developing The Horse and TheHorse.com.
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