Newsdate: Friday, April 14 2023 - 8:00 am
Location: TEMPE, Arizona
In 2022, we were delighted to announce preliminary findings of very favorable responses to canagliflozin (Invokana®) in severely laminitic horses with hyperinsulinemia unresponsive to the usual diet and drug therapy. Kellon and Gustafson (2022)
Illustration of what happens to horse's foot anatomy in severe case of laminitis
The war against hyperinsulinemia to prevent laminitis rages on.
© 2020 byJoAnne Rissanen New window.
Things were progressing smoothly for the first two years until a horse was noted to be hyperlipidemic (high blood triglycerides). The horse was hospitalized as a suspected colic but continued to be bright and eating well with triglycerides coming down rapidly with therapy and off the drug.
We immediately informed owners and their treating veterinarians of the risk of hyperlipidemia/hypertriglyceridemia and advised screening both before therapy and serially after starting therapy. We have found that the vast majority of horses on canagliflozin or ertugliflozin develop high triglyceride levels. Detailed information on these cases has been recently published. Kellon and Gustafson (2023)
Except for mild to moderate weight loss, these horses showed no evidence of the life-threatening hyperlipemia syndrome reported in donkeys, ponies, and miniature horses. We also found that animals in those high-risk groups for hyperlipemia did not develop more severe hypertriglyceridemia with these drugs. We believe the hypertriglyceridemia is in response to an energy shortage caused by the loss of glucose in the urine, similar to what occurs with fasting/starvation and during endurance exercise.
While our 2023 paper was under review, Sundra, et al. (2022) reported on responses to ertugliflozin in horses in Australia. They found similar triglyceride elevations without symptoms. This is consistent with the report of Dunkel, et al. (2013)where it was noted horses with metabolic disorders may be hyperlipidemic for many years, including with liver enzyme elevations, yet show no obvious ill effects.
Nevertheless, because of the potential for development of fatty liver we recommend diets be liberalized to free-choice safe hay and 1 to 2 lbs of beet pulp daily for full-size horses. This allows for an increase in safe calories and the acetate from fermentation of beet pulp and hay can substitute directly for glucose. Other dietary measures are also being investigated.
We wish to especially recognize the members and volunteers of the ECIR Group Inc. for their contribution of time, resources, and data, without whom help for metabolic equines would not be possible.
REFERENCES
Kellon EM, Gustafson KM. (2022) Use of the SGLT1 inhibitor canagliflozin for control of refractory equine hyperinsulinemia and laminitis. Open Vet J. 12:511-518.
Kellon EM, Gustafson KM. (2023) Hypertriglyceridemia in equines with refractory hyperinsulinemia treated with SGLT2 inhibitors. Open Vet J. 13:365-375.
Sundra, T., Kelty, E. & Rendle, D. (2022) Preliminary observations on the use of ertugliflozin in the management of hyperinsulinaemia and laminitis in 51 horses: A case series. Equine Veterinary Education, 00:1– 10.
Dunkel B, Wilford SA, Parkinson NJ, Ward C, Smith P, Grahame L, Brazil T, Schott HC 2nd. (2014) Severe hypertriglyceridaemia in horses and ponies with endocrine disorders. Equine Vet J. 46:118-22.
About ECIR Group Inc.
Started in 1999, the ECIR Group is the largest field-trial database for PPID and EMS in the world and provides the latest research, diagnosis, and treatment information, in addition to dietary recommendations for horses with these conditions. Even universities do not and cannot compile and follow long term as many in-depth case histories of PPID/EMS horses as the ECIR Group.
In 2013 the Equine Cushing’s and Insulin Resistance Group Inc., an Arizona nonprofit corporation, was approved as a 501(c)3 public charity. Tax deductible contributions and grants support ongoing research, education, and awareness of Equine Cushing’s Disease/PPID and EMS.
THE MISSION of the ECIR Group Inc. is to improve the welfare of equines with metabolic disorders via a unique interface between basic research and real-life clinical experience. Prevention of laminitis is the ultimate goal. The ECIR Group serves the scientific community, practicing clinicians, and owners by focusing on investigations most likely to quickly, immediately, and significantly benefit the welfare of the horse.
Press release by Nancy Collins