Use of a deslorelin implant to induce estrus in coyotes (Canis latrans)

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Reproduction in Domestic Animals







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Subcutaneous deslorelin implants have been used in wolves (Canis lupus) and domestic dogs (C. l. familiaris) to induce estrus, which is often necessary when planning artificial inseminations. An induction protocol can also serve to synchronize estrus in females, if more than one is to be inseminated. The objective of this study was to determine if a subcutaneous, time-released deslorelin implant would induce estrus in coyotes (C. latrans). Deslorelin implants (2.1 mg, OvuplantÒ; Peptech Animal Health Pty Limited, NSW, Australia) were placed subcutaneously in the inguinal region of six, sexually mature female coyotes located at the National Wildlife Research Center’s Predator Research Facility in Utah, USA, on January 3, 2012. Six female coyotes housed at the same facility did not receive implants and were monitored as controls. Sixteen days later, serum progesterone concentrations, measured by chemiluminescent microparticle immu- noassay, were elevated above baseline (>2.0 ng/ml; range of 1.0– 40.5 ng/ml, median = 12.3 ng/ml) in five of six treated females compared with an elevation in 1 of 6 females in the control group (range of 0.3–3.8 ng/ml, median = 0.9 ng/ml). Serum progesterone concentrations were log-transformed and analyzed by two-sample t- test, binary data (elevated v. not elevated) were analyzed by fisher’s exact test. Coyotes receiving implants had higher serum progesterone concentrations than control coyotes (p < 0.05) and treated animals had elevated serum progesterone levels over baseline compared to control animals (p = 0.08). Vaginal cytological evaluation in the treated females revealed cells consistent with estrogen influence. To our knowledge, this is the first report of induction and synchronization of estrus in coyotes. This technique may be valuable in breeding management, especially using semen from males not located at the same facility