Are warmblood breeds prone to endocrine disorders, such as pituitary pars intermedia dysfunction (PPID) and insulin dysregulation (ID)? Researchers say yes.

At the 5th Global Equine Endocrine Symposium (GEES), presented by Boehringer Ingelheim, Rachel Lemcke, MS, of Amwell Data Services LLC, in New Jersey, shared findings from research she conducted with Steve Grubbs, DVM, PhD, DACVIM, and Kelly Graber of Boehringer Ingelheim Animal Health USA. Their retrospective analysis on veterinarian-provided data from 2016-2020 in the U.S. compared rates of endocrine disorders among nine warmblood breeds. The study included 1,485 warmbloods with suspected endocrine disorders (primarily PPID).

In addition to comparing rates of endocrine disorders, the researchers also examined the frequency of endocrine-associated clinical signs in three specific warmblood breeds (Dutch Warmblood, Hanoverian, and Oldenburg) versus non-breed-specific warmbloods. 

The study identified endocrine disorders such as PPID and ID in 55-85% of specific warmblood breeds versus 69% of non-breed-specific warmbloods. Within the study population, the rate of warmbloods diagnosed with PPID only was significantly lower than the rate of warmbloods diagnosed with ID or no identifiable endocrine disorder. There was no significant difference in endocrine disorder prevalence among any warmblood breed evaluated. 

Signs of Endocrine Disease in Warmbloods

Of the three warmblood breeds compared to non-breed-specific warmbloods, regional adiposity was the only statistically significant endocrine-associated clinical sign. Oldenburgs had a lower rate of regional adiposity regardless of endocrine classification versus non-breed-specific warmbloods. 

Among all warmblood breeds evaluated, regional adiposity rates were highest in horses with PPID and ID versus horses with PPID alone. Rates of decreased athletic performance and laminitis were not statistically associated with any endocrine classification.

“Rates of regional adiposity were lowest in PPID-only horses instead of horses without identified endocrine disorders, as was expected, further highlighting the need for dynamic testing,” the researchers stated. “Hair coat changes were statistically associated with horses with PPID as well as those without endocrine disorders. This suggested that many horses in this study may have undiagnosed PPID.”

Final Words

Endocrine testing is crucial when managing older warmbloods, especially for those working as schoolmasters. Senior warmblood owners should be on the lookout for both PPID and ID. Veterinarians should use dynamic testing methods to confirm a diagnosis.

Author’s note: Since the testing primarily used static testing instead of dynamic testing (i.e., TRH stimulation tests and oral sugar tests), the estimates are likely low. In addition, the sample populations were skewed (not fully representative of the breeds) since the study was trying to identify horses with at least one endocrine-associated clinical sign and looking for PPID-suspected horses.

You can access the full Proceedings of the 5th GEES Symposium here.

Further Reading

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  • Kimberly S. Brown and Jewell

    Kimberly S. Brown is an award-winning writer and publisher. She founded My Senior Horse for Equine Network and Linda Mars in her retirement, and now she is an editor of the brand. Brown previously had spent 10 years at Equine Network. 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 award-winning The Horse and TheHorse.com.

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