Bad Behavior and Possible Neck Pain in Mares 

At the Kester News Hour during the 2023 AAEP Convention, Amy Johnson, DVM, DACVIM-LAIM, of the University of Pennsylvania’s New Bolton Center, discussed a study on hormone profiles submitted for 2,914 mares with owner-reported behavioral abnormalities to the diagnostic lab at the University of California, Davis.  

Johnson said 86% of the mares did not have hormone problems indicative of a potential granulosa cell tumor. Based on this result, she suggested if a mare is bucking, bolting, kicking, rearing, spooking, biting, and/or vocalizing, don’t just blame it on hormones.  

Another potential cause of behavioral problems is neck pain from conditions such as osteoarthropathy, foraminal stenosis, or cervical nerve root compression (radiculopathy). Johnson described a study in which researchers used ultrasound guidance to inject 1.5 ml iodinated contrast/latex into the cervical nerve roots of five anesthetized mares. This technique was found to be accurate (resulting in direct contact) 75% of the time. The study authors stressed that inadvertent injection of arteries, spinal cord, or vertebral canal can be life-threatening. In summary, ultrasound guidance is not always a guarantee of success.  

References

• Huggins, L.; Norris, J.; Conley, A. et al. Abnormal mare behavior is rarely associated with changes in hormonal markers of granulosa cell tumors: A retrospective study. Equine Vet J 2023. htps://doi.org/10.1111/evj.13967 
• Fouquet, G.; Abbas, G.; Johnson, JP. et al. Ultrasound-guided injection technique of the equine cervical nerve roots. Front Vet Sci 2022 Oct 26:9:992208. htps://doi:10.3389/fvets.2022.992208