As horses age, their needs evolve—and so should our understanding of how to care for them. This September, Equine Guelph is shining a spotlight on eye health in senior horses as part of their annual Senior Horse Education Month. Horse owners are invited to explore this year’s theme, ‘A Clearer View,’ through two resources: the free Senior Horse Challenge and a Senior Horse online short course with expert instructor Dr. Bettina Bobsien, from Sept 29 – Oct 10 2025.
Horse's eye with signs of chronic uveitus.
The Senior Horse Challenge tool is a free, interactive resource that helps horse owners assess their knowledge of common age-related health concerns, including ocular issues
© 2032 by Dr. Rana Bozorgmanesh New window.
“Often mistaken for behaviour issues, senior horses can experience a range of age-related eye issues,” says Bobsien. “From cataracts to equine recurrent uveitis (ERU), these conditions can impact a horse’s comfort, confidence, and safety.”
ERU—also known as moon blindness—is one of the leading causes of blindness in horses worldwide. This autoimmune condition causes painful, recurring inflammation in one or both eyes, which can lead to scarring, cataracts, and vision loss over time.
In some cases, vision problems in senior horses may be more than just age-related. Pituitary Pars Intermedia Dysfunction (PPID), a common endocrine disorder in older equids, has been associated with several ocular complications, including conjunctivitis, corneal ulcers, and even blindness in advanced stages.
A 2023 review of clinical guidelines noted that corneal ulceration, while not a primary diagnostic sign, is among the ocular conditions observed in horses with PPID. Although the evidence is rated as ‘very low’ in terms of direct association, the presence of such signs in older horses should prompt consideration of endocrine testing.
The Senior Horse Challenge tool is a free, interactive resource that helps horse owners assess their knowledge of common age-related health concerns, including ocular issues. It also offers practical tips for spotting early signs of trouble, such as:
- Tearing, squinting, or cloudiness in the eye
- Changes in corneal color or the appearance of spots
- Hesitation in low light or difficulty navigating obstacles
After completing the free tool, horse owners and care givers can deepen their understanding and gain ‘a clearer view’ of their aging equids needs by enrolling in the upcoming Senior Horse online short course, running from Sept 29 – Oct 10, 2025. Designed for busy equine caregivers, the course offers practical, evidence-based learning on topics ranging from nutrition and mobility to vision care and pain management.
“Recognizing symptoms early can lead to faster diagnosis and treatment, reducing the risk of permanent damage,” says Bobsien “And the good news is, horses often adapt well to changes in vision—especially when their caregivers are informed and proactive.”
“There are several simple ways owners can assess whether their horse might be experiencing vision issues,” says Dr. Wendy Cullen from the Caradoc Animal Clinic, who recently examined an Equine Guelph staff member’s senior horse, Lucky, for a suspected eye condition. “Watch how your horse navigates obstacles, especially in changing light conditions. If they seem startled when approached or show differences between eyes, it could indicate a problem.”
Dr. Cullen recommends a few easy at-home tests: Try covering one eye at a time using a fly mask and gauze, then lead your horse over a garden hose or across surfaces with abrupt colour changes—like grass to asphalt. Hesitation may signal vision impairment. You can also perform a simple menace test by waving your hand about six inches from each eye (with the opposite eye covered). A normal eye should blink or flinch—just be careful not to create air currents that could skew the result.
Veterinary research has shown that horses with PPID may experience decreased corneal sensitivity, which can impair healing of eye injuries and increase the risk of chronic discomfort. Elevated cortisol levels in the tears of PPID-affected horses may further delay corneal wound healing, underscoring the importance of early diagnosis and management of this condition.
Horse owners should learn the signs of potential metabolic issues and consider endocrine screening as part of their senior horse care routine. The Senior Horse Challenge tool and Senior Horse Course include resources to help identify signs that may warrant further investigation beyond laminitis, fat pads, weight loss and changes to the hair coat.
“As horses are living longer, maintaining their health and well-being is imperative for their quality of life,” says Randy Trumpler, Equine Business Unit Director at Boehringer Ingelheim. “This online tool and The Senior Horse course offered by Equine Guelph are great resources that provide practical ways to prepare for your horse’s golden years.”
Equine Guelph thanks Boehringer Ingelheim Animal Health Canada for sponsoring both of its senior horse online resources – the free tool and Senior Horse online course.
Take the Challenge: Senior Horse Challenge
Register Now: Senior Horse online short course – Sept 29 – Oct 10, 2025
References:
Menzies-Gow, N. J., Banse, H. E., Duff, A., Hart, N., Ireland, J. L., Knowles, E. J., McFarlane, D., & Rendle, D. (2024). BEVA primary care clinical guidelines: Diagnosis and management of equine pituitary pars intermedia dysfunction. Equine Veterinary Journal, 56(2), 220-242. https://doi.org/10.1111/evj.14009
Beech, J., Boston, R. C., & McFarlane, D. (2017). Recommendations for the diagnosis and treatment of pituitary pars intermedia dysfunction (PPID). In D. McFarlane (Ed.), Equine Endocrinology Group Guidelines. Retrieved from https://www.bicanadaequine.ca/ppid/ppid-symptoms
Equine Guelph is the horse owners’ and care givers’ Centre at the University of Guelph in Canada. It is a unique partnership dedicated to the health and well-being of horses, supported and overseen by equine industry groups. Equine Guelph is the epicentre for academia, industry and government – for the good of the equine industry as a whole. For further information, visit www.equineguelph.ca.
Press release by Amy Sales - Story by: Jackie Bellamy-Zions