Background: Ponies have been shown to have high rates of endocrine disorders (ED), but ED and endocrine-associated clinical sign (EACS) frequencies among pony breeds are poorly understood.
Hypothesis/
Objectives: The objective was to compare PPID and ID status and frequency of EACS within pony breeds. Animals: Ponies (n=3,231) with EACS were tested for ED by their veterinarian.
Methods: A retrospective analysis was performed on a 2016-2023 study of ponies with suspected ED. Ponies enrolled before 2021 were considered PPID positive if spring basal, spring post-TRH-stimulated, or fall basal ACTH levels were >35, >110, or >50 pg/mL, respectively; if enrolled after 2020, cutoffs were >30, >110, or >100 pg/mL, respectively. Ponies were considered ID positive if basal insulin levels >20 uIU/mL. Frequencies of PPID, ID, laminitis, hair coat changes, regional adiposity, decreased athletic performance/lethargy, and recurrent infections were analyzed using chi-square or two-way ANOVA.
Results: Two thirds of each pony breed had at least one ED, with both PPID and ID identified in more than 25 percent of each breed. ID was more prevalent than PPID in all pony breeds. PPID and ID rates were highest in Hackneys and Shetlands at 62.22 and 79.12 percent, respectively, while Haflingers had the lowest rate of either ED at 32.76 and 61.49 percent, respectively. EACS rates were not statistically significantly different among pony breeds (p >0.9999), but all signs evaluated were statistically associated with endocrine classification (p=0.0024 to < 0.001).
Conclusion/Clinical Importance: These observations demonstrate the need for in-depth endocrinology testing and management for ponies.
