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Physiological effects of gonadotropinreleasing hormone immunocontraception on white-tailed deer

Curtis, P.D., Richmond, M.E., Miller, L.A., Quimby, F.W.
Human-wildlife conflicts 2008 v.2 no.1 pp. 68
Odocoileus virginianus, deer, contraception, contraceptives, gonadotropin-releasing hormone, vaccination, adverse effects, animal pathology, granuloma, injection site, blood chemistry, reproductive system, females, bucks
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 signifi cant differences in ovary (F2,22 = 0.31, P = 0.73), or pituitary weights (F2,22 = 0.30, P = 0.75) between treatment groups. Ovaries from control females had signifi cantly more secondary follicles (F2,21 = 20.56, P <or= 0.001), but not Graafi an follicles (F2,22 = 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.