Physiological effects of gonadotropin-releasing hormone immunocontraception on white-tailed deer

Authors

Paul D. Curtis, Cornell UniversityFollow
Milo E. Richmond, USGS-BRD, New York Cooperative Fish and Wildlife Research Unit, Cornell University, Ithaca, NY
Lowell A. Miller, USDA/APHIS/Wildlife Service’s National Wildlife Research CenterFollow
Fred W. Quimby, Rockefeller University

Document Type

Article

Date of this Version

5-1-2008

Comments

Published in Human–Wildlife Conflicts 2(1):68–79, Spring 2008.

Abstract

Before immunocontraceptives can be considered safe to use on wildlife species, potential health risks should be assessed. Gonadotropin-releasing hormone (GnRH) immunocontraceptive has successfully reduced fertility of white-tailed deer (Odocoileus virginianus); however, associated deer physiology has rarely been examined. We conducted gross necropsy examinations, histology, and blood chemistry comparisons on euthanized deer previously vaccinated with immunogenic GnRH (n = 18 females and n = 4 males), or left as untreated controls (n = 7 females and n = 6 males). Granulomas were found at injection sites of most deer, even 3 years post-treatment. There were no significant differences in ovary (F_2,22= 0.31, P = 0.73), or pituitary weights (F_2,22 = 0.30, P = 0.75) between treatment groups. Ovaries from control females had significantly more secondary follicles (F2,21 = 20.56, P ≤ 0.001), but not Graafi an follicles (F_2,22= 2.22, P = 0.13). Immunized males had significantly lower mean testes weights, a number of morphologic abnormalities, and varying degrees of aspermatogenesis with fewer mature spermatozoa. We do not recommend treating male deer with anti-GnRH immunocontraceptive vaccines.