Theriogenology

Theriogenology is a specialized branch of animal science focused on reproduction, veterinary obstetrics, the physiology of animals’ reproductive organs and systems, and the illnesses and disorders that can affect them. Its professional practitioners are known as theriogenologists and primarily concentrate on domesticated animals such as dogs, cats, horses, poultry, and livestock. However, the field’s scope extends to all animals treated by veterinarians, domesticated and wild, including exotic species.

In the United States, two professional organizations support theriogenologists and their work—the American College of Theriogenologists (ACT) and the Society for Theriogenology. The ACT is recognized by the American Veterinary Medical Association (AVMA) and works to establish and advance postgraduate education and training standards. The Society for Theriogenology is an international information-sharing forum on emerging field-specific research.

Background

In 1954, the organization now known as the Society for Theriogenology held its first meeting. Led by a small number of veterinary colleagues, the society initially focused exclusively on scientific techniques for determining and improving the reproductive viability of bulls. The organization was chartered under Colorado law in 1961 and underwent a period of rapid growth during the early 1960s, absorbing similar regional societies based in California, Texas, Montana, the Missouri Valley, and the Southeastern United States. At this time, the organization was known as the American Society for the Study of Breeding Soundness.

By the late 1960s, the society had formed an organizing committee, which approached the AVMA seeking to establish a recognized veterinary medicine specialization focused on animal reproduction. The committee also aimed to create an accompanying term for the proposed specialization supplied by University of Wisconsin professor Herbert M. Howe (1912–2010). Howe applied his knowledge of the ancient Greek and Latin languages to coin the term theriogenology, drawing from root words including therio meaning “animal” or “beast,” genesis meaning “creation,” and -ology meaning “the study of.” The word theriogenology began appearing in unabridged English dictionaries in the early 1970s. In 1974, the American Society for the Study of Breeding Soundness officially changed its name to the Society of Theriogenology.

Since the 1970s, theriogenology has been recognized as an animal science specialization uniquely focused on the diagnosis and medical management of reproductive system disorders affecting male and female animals of all species covered by practitioners of veterinary medicine. Its subfields include animal andrology and gynecology, urology, obstetrics, perinatology and neonatology, endocrinology, and the epidemiology and pathology of reproductive diseases and conditions in animals. Theriogenology also deals with the study, development, and application of assisted reproductive techniques and the reproductive management of animal herds.

Overview

Though theriogenology is a specialized branch of veterinary medicine, its scope covers many concentrated subfields, which combine to define the purview of the field. These include animal andrology and gynecology, which focus on diagnosing, treating, and managing injuries, diseases, and chronic conditions affecting male and female animals’ reproductive and urinary tracts. Veterinary urologists, who deal with the medical and surgical management of urinary tract diseases and disorders in animals, are also considered specialist theriogenologists. Animal endocrinology—the study of hormones and the endocrine systems that produce them—also falls under veterinary concentrations within theriogenology.

In practice, theriogenology’s obstetric, perinatal, and neonatal orientations represent one of the field’s most impactful applications. Veterinary obstetricians specialize in managing animal pregnancies, addressing complications, guiding animal births, and offering postpartum care to mother and baby animals. Perinatology concentrates more specifically on the periods immediately preceding, during, and after birth, while veterinary neonatology covers the medical care of newborn animal babies, especially those born prematurely and those with birth defects or congenital illnesses.

Beyond serving the owners of individual pets, theriogenologists assist animal breeders, ranchers, and animal agriculturalists. Dog and cat breeders routinely consult animal reproductive specialists when seeking to increase their commercial purebred stock assets, while equine breeders often retain their services when selectively creating pedigree show animals and racehorses. In some cases, theriogenologists deploy assisted reproductive techniques to help animals with particularly appealing pedigrees overcome reproductive problems or limitations and create offspring.

The reproductive management of animal herds represents another key commercial application of theriogenology. In this capacity, theriogenologists work to optimize the reproductive efficiency (pregnancy rate) of herd animals such as cattle, using their specialized medical knowledge to guide calving-to-conception intervals toward peak productivity and draw on existing scientific cattle breeding practices. According to veterinary manuals, this process encompasses nine distinct steps—(1) identifying the male and female members of the herd to be used in breeding programs based on their genetics, fertility characteristics, and other aspects of their physical and temperamental profiles; (2) maintaining detailed records, tracking pregnancy rates, culling rates, the breeding success of male animals, and offspring mortality and morbidity rates; (3) implementing nutritional programs that optimize fertility and breeding success; (4) creating strategic programs to replace female breeding partners as they age; (5) managing the reproductive health of male breeding partners; (6) creating immunization and vaccination programs for the herd as a whole as well as the animals identified as breeders; (7) tracking spontaneous abortion and reproductive failure rates among male and female animals; (8) maintaining facilities that optimize the reproductive health of resident animals; and (9) providing neonatal care to newborn animals.

Though theriogenology is recognized as a vital and commercially valuable veterinary specialization, associated educational resources began a downward trend in the early 2000s. According to a report published in the Journal of Veterinary Medical Education, the number of board-eligible theriogenology specialists working at veterinary colleges in North America and the Caribbean remained stable between 1995 and 2005. However, the number of such professionals on the faculties of accredited veterinary colleges declined at more than 57 percent of surveyed institutions.

Bibliography

“American College of Theriogenologists.” American College of Theriogenologists, 2021, www.theriogenology.org. Accessed 10 Mar. 2021.

Christensen, Bruce W. Theriogenology, An Issue of Veterinary Clinics of North America: Small Animal Practice. Elsevier Health Sciences, 2018.

DeCramer, Kurt G. M., and Sooryakanth Sasidharan. Dog Breeding: A Complete Reference Book. Kejafa Knowledge Works, 2019.

Presicce, Giorgio. Reproductive Technologies in Animals. Academic Press, 2020.

Root Kustritz, and Margaret V. The Dog Breeder's Guide to Successful Breeding and Health Management. Cambridge Scholars Publishing, 2019.

Root Kustritz, Margaret V., Ahmed Tibary, and Peter J. Chenoweth. “Availability of Theriogenology Training at North American and Caribbean Veterinary Colleges.” Journal of Veterinary Medical Education, vol. 33, no. 1, 2006, pp. 140–144. doi.org/10.3138/jvme.33.1.140. Accessed 20 May 2024.

Statham, Jonathan. “Overview of Management of Reproduction: Cattle.” Merck Sharpe & Dohme Corporation, Mar. 2023, www.msdvetmanual.com/management-and-nutrition/management-of-reproduction-cattle/overview-of-management-of-reproduction-cattle. Accessed 20 May 2024.

“Society for Theriogenology.” Society for Theriogenology, www.therio.org. Accessed 20 May 2024.