Hemodialysis Successfully Saves Horse from Maple Toxicosis

A Quarter Horse mare has been saved from silver maple toxicosis through hemodialysis for the first time. The horse arrived at the Ohio State University clinic approximately 12 hours after beginning to show symptoms of maple poisoning. The wilting leaves of certain maple trees, such as red, sugar, and silver, contain toxins that impact the hemoglobin in red blood cells, inhibiting their oxygen transport capabilities. Additionally, the toxins cause the destruction of red blood cells and subsequent waste buildup which can harm the kidneys.

Common symptoms of this condition include lethargy, elevated heart and respiratory rates, dark red gums, and coffee-colored urine. With standard supportive care, including intravenous fluids and sometimes blood transfusions, about half of the horses affected by maple leaf toxicity manage to survive hospital discharge. Acute kidney injury is a significant risk of maple leaf toxicity, and there have been no prior reports of effective hemodialysis treatment for adult horses experiencing this complication. Erin Pinnell, DVM, noted that after stabilizing the mare with medications and a blood transfusion, her elevated kidney values prompted the consideration of hemodialysis.

This procedure, which filters waste from the blood when kidneys fail to function properly, has been traditionally rare in equine practice. It has been utilized successfully in foals but is uncommon in adult horses. With guidance from small animal specialists, the Ohio State team facilitated the mare’s two hemodialysis treatments. Initially sedated yet comfortable, the mare was able to eat hay during the six to eight-hour procedures without any complications. Following the second treatment, the mare’s kidney values showed significant improvement to near normal levels, negating the need for a third treatment. This successful case suggests that hemodialysis may be a feasible treatment for horses with acute kidney injury.

However, Pinnell cautioned that this approach is not suitable for horses with chronic kidney disease at this time. The findings were published in the Journal of Veterinary Internal Medicine in April 2024.