The Canadian Veterinary Medical Association (CVMA), Federation of Veterinarians of Europe (FVE), and American Veterinary Medical Association (AVMA) recently endorsed the World Veterinary Association (WVA) Position Statement on Use of Horses for Production of Biologics and Therapeutics1 in recognizing that compliance with the cited recommendations for the care of horses used in these industries is necessary to ensure their good welfare. These recommendations, published in two articles in the peer-reviewed journal Animals in 2019 and 2021, and authored by members of the WVA and FVE Animal Welfare Committees2,3, include important considerations for horses used in the production of Pregnant Mare Serum Gonadotropin (PMSG) also known as equine chorionic gonadotropin (eCG).
PMSG/eCG, is a complex glycoprotein hormone obtained from the serum of pregnant mares. It is secreted at 40 to 130 days gestation from fetal-origin trophoblastic epithelial cells that form the endometrial cups of the pregnant mare. It is found circulating in blood but is not excreted in the mare’s urine; therefore, blood collection is a necessity in the production process. Ultimately, PMSG/eCG is used to increase reproductive performance in various areas of animal use including food animals, laboratory animals and in zoological conservation efforts.
The main geographic locations for collection of blood from pregnant mares for production of PMSG/eCG have historically been South America, Asia and Iceland. However, irrespective of the location of the production unit, animal welfare must be the highest priority. Following media attention, concerns have been raised regarding the welfare of mares used for blood collection in this industry.
Industries using animals as part of product development should adhere to guidelines and recommendations, such as those cited in the WVA Position Statement on Use of Horses for Production of Biologics and Therapeutics or similar standards that are scientifically based and that also consider societal expectations for the use of animals for human purposes. In the collection of blood for PMSG/eCG, there is a need for standard setting, guideline development, and audit programs, as well as a need for improved transparency, to ensure that blood is obtained from pregnant mares by methods that comply with animal welfare standards as outlined in the WVA Position Statement.
The FVE, CVMA, and AVMA align with the WVA in calling for the welfare of animals under human care to be given the highest priority. To that end, protecting the welfare of donor horses must be a major consideration in the production of PMSG (eCG), and continued research into the development of effective alternatives, including synthetic analogs, should be prioritized.
1 WVA Position Statement on Use of Horses for Production of Biologics and Therapeutics, World Veterinary Association, 14 April 2022, https://worldvet.org/policies/wva-position-statement-on-the-use-of-hors… (accessed 02 August 2023).
2 Manteca-Vilanova X, Beaver B, Uldahl M, Turner PV. Recommendations for ensuring good welfare of horses used for industrial blood, serum, or urine production. Animals 2021; 11(5):1466, doi:10.3390/ani11051466
3 Manteca-Vilanova X, De Briyne N, Beaver B, Turner PV. Horse welfare during equine chorionic gonadotropin (eCG) production. Animals 2019; 9(12):1053, doi:10.3390/ani9121053.