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Abstract: About 75% of dogs worldwide are free to roam and reproduce, thus creating locally overabundant populations. Problems caused by roaming dogs include diseases transmitted to livestock and humans, predation on livestock, attacks on humans, road traffic accidents, and nuisance behavior. Nonsurgical fertility control is increasingly advocated as more cost-effective than surgical sterilization to manage dog populations and their impact. The aims of this review were to 1) analyze trends in numbers of scientific publications on nonsurgical fertility control for dogs; 2) illustrate the spectrum of fertility inhibitors available for dogs; 3) examine how differences between confined and free-roaming dogs might affect the choice of fertility inhibitors to be used in dog population management; and 4) provide a framework of criteria to guide decisions regarding the use of nonsurgical fertility control for dog population management. The results showed that the 117 articles published between 1982 and 2011 focussed on long-term hormonal contraceptives, such as gonadotropin-releasing hormone agonists, immunocontraceptives, and male chemical sterilants. The number of articles published biennially increased from one to five papers produced in the early 1980s to 10 to 20 in the past decade. Differences between confined dogs and free-roaming dogs include reproduction and survival as well as social expectations regarding the duration of infertility, the costs of sterilization, and the responsibilities for meeting these costs. These differences are likely to dictate which fertility inhibitors will be used for confined or free-roaming dogs. The criteria regarding the use of fertility control for dog population management, presented as a decision tree, covered social acceptance, animal welfare, effectiveness, legal compliance, feasibility, and sustainability. The review concluded that the main challenges for the future are evaluating the feasibility, effectiveness, sustainability, and effects of mass nonsurgical sterilization campaigns on dog population size and impact as well as integrating nonsurgical fertility control with disease vaccination and public education programs. [Copyright &y& Elsevier]

Highlights: [•] A vaccine to prevent adrenal cortical disease (ACD) in domestic ferrets is proposed. [•] GonaCon immunocontraceptive vaccine prevented ACD by causing production of antibodies to GnRH. [•] ACD was reduced in ferrets treated with GonaCon compared to untreated ferrets. [•] Subcutaneous vaccination with GonaCon is recommended to prevent onset of ACD in domestic ferrets. [ABSTRACT FROM AUTHOR]

This manuscript provides an overview of past wildlife contraception efforts and discusses the current state of research. Two fertility control agents, an avian reproductive inhibitor containing the active ingredient nicarbazin and an immunocontraceptive vaccine, have received regulatory approval with the Environmental Protection Agency and are commercially available in the USA. OvoControl G Contraceptive Bait for Canada Geese and Ovo Control for pigeons are delivered as oral baits. An injectable immunocontraceptive vaccine (GonaCon Immunocontraceptive Vaccine) was registered with the Environmental Protection Agency for use in female white-tailed deer in September 2009. An injectable product (GonaCon Immunocontraceptive Vaccine) is registered for use in female white-tailed deer. Both products are labeled for use in urban/suburban areas where these species are overabundant. Several other compounds are currently being tested for use in wildlife in the USA, Europe, Australia and New Zealand that could have promise in the future. The development and use of reproductive inhibitors for resolving human–wildlife conflicts will depend on a number of factors, including meeting the requirements of regulatory agencies for use in the environment and on the biological and economical feasibility of their use. Use will also be dependent on health and safety issues and on public acceptance of the techniques. [ABSTRACT FROM AUTHOR]

Problem An effective, single-injection, multi-year, GnRH contraceptive agent is needed to control reproduction in overabundant white-tailed deer populations. Method of study Two GnRH conjugates, GonaCon™ (GnRH–KLH) and GonaCon-B™ (GnRH–blue protein), were prepared in emulsion form as one-injection and two-injection immunocontraceptive vaccine formulations. In addition, the GnRH–KLH protein conjugate was lyophilized and suspended in AdjuVac™ adjuvant to produce a fifth vaccine formulation. Each formulation was administered to a group of five captive adult female white-tailed deer. Reproductive performance of treated female deer was monitored for 5 years to determine the comparative efficacy of the various treatments. Results The longevity of the contraceptive response (2–5 years) was strongly influenced by the design of the conjugate antigen, the adjuvant used, and the delivery form of the vaccine. Conclusion One-injection and two-injection formulations of GonaCon™ and GonaCon-B™ produced multi-year contraception in adult female white-tailed deer. GonaCon-B™ provided a longer lasting contraceptive effect. [ABSTRACT FROM AUTHOR]

The development of nonsurgical contraceptives for cats may facilitate population control of the species. The purpose of this study was to investigate the utility of GnRH for immunocontraception of male cats. Male cats (n=12) were divided into groups of three and were immunized once with 0 (sham), 50, 200, or 400 μg synthetic GnRH coupled to keyhole limpet hemocyanin and combined with a mycobacterial adjuvant to enhance immunogenicity. GnRH antibody titer, serum testosterone concentration, and scrotal size were determined monthly. At 6 months, semen was collected by electroejaculation and testes were examined histologically. GnRH antibodies were detected in all cats receiving GnRH vaccine by 1 month post-treatment and persisted throughout the study. No dose effect of GnRH was observed; titers were not different among cats treated with 50, 200, or 400 μg GnRH (P=0.5). Six of nine treated cats were classified as responders based on high GnRH antibody titers (>32,000). By 3 months post-treatment, responder cats had undetectable testosterone concentrations and testicular atrophy. Nonresponder cats had GnRH titers of 4000–32,000 and testosterone concentrations intermediate between responder and sham-treated cats. At 6 months, total sperm counts were similar for sham-treated cats (3.1±1.8×106 sperm) and nonresponder cats (3.4±1.6×106 sperm; P=0.7). Only one of the six responder cats produced sperm, none of which were motile. Combined testicular weights of responder cats (1.3±0.1 g) were lower than sham-treated controls (5.3±1.3 g; P=0.02) and nonresponder cats (2.9±0.3 g; P=0.02). Histologic evaluation of the testes revealed that in responder cats, the interstitial cells that were present were pale and shrunken compared to the plump, polyhedral eosinophilic cells in sham-treated cats. GnRH responder cats had marked tubular atrophy with vacuolated Sertoli cells and a paucity of germ cells. Single-dose GnRH treatment resulted in testosterone concentrations and semen quality consistent with immunocastration in a majority of cats treated. [Copyright &y& Elsevier]

Native porcine zona pellucida (PZP) has been shown to be highly effective as an immunocontraceptive in white-tailed deer. However, the immunogenicity of PZP extracted from pig ovaries may vary from lot to lot and the extract has the potential of containing either viral or pathogenic material. Determination of the immunocontraceptive epitopes of PZP would allow portions of the molecule to be synthesized or inserted into a recombinant system for production of a consistent and safe vaccine. In this study, epitopes of PZP were selected and tested by in vitro binding, immunogenicity in rabbits, immunogenicity and immunocontraception in deer.Sera from PZP immunocontracepted deer were tested on ELISA plates containing immobilized peptides from ZP1 and ZP3α. Peptides with which sera from infertile deer reacted (six peptides from ZP1 and six peptides from ZP3α) were selected, synthesized and tested for immunogenicity in rabbits. Deer were then immunized with combinations of peptides from either the ZP1 or ZP3α groups. ZP3α peptides induced high immune titers against native PZP, but did not induce infertility in the deer. Although ZP1 peptides induced lower titers, deer immunized with two ZP1 peptides exhibited multiple estrus events and infertility, typical of that for deer immunized with native PZP vaccine. Competitive inhibition assays using the ZP1 peptides demonstrated that the peptide comprising pins 10–16 was most effective in blocking binding by the serum antibody of native PZP immunized deer. This peptide was used to immunocontracept deer, resulting in a significant reduction in fawning for 1 year. [Copyright &y& Elsevier]

Presents information on a study which examined the contraceptive and health effects of porcine zona pellucida immunocontraception on white-tailed deer. Methodology; Results of the study; Discussion.

Presents information on immunocontraception, a concept of wildlife management for conflicts between humans and animals. Historical background; Details on contragestion, a process of causing infertility by interfering with gestation; Discussion on contraceptive vaccines; Impact of immunocontraception on wildlife management.

Abstract: The uncontrolled reproduction of free-roaming feral cats contributes to overpopulation and associated concerns regarding their welfare and impact on public health and the environment. Nonsurgical fertility control that could be administered to feral cats in the field would be a powerful tool for cat population control. The objective was to test the efficacy and duration of activity of a single-dose GnRH immunocontraceptive vaccine (GonaCon™) on the fertility of adult female laboratory cats. Vaccinated cats (n = 15) received a single injection of vaccine containing a GnRH-KLH conjugate (200 μg) emulsified in a mycobacterial and oil adjuvant on study Day 0. Sham-treated cats (n = 5) received a single injection containing all vaccine components except the GnRH-KLH conjugate. A breeding trial started on study Day 120. Vaccinated cats had a longer time to conception (median 39.7 mo) compared to sham-treated cats (4.4 mo; P < 0.001). A total of 93% of vaccinated cats remained infertile for the first year following vaccination, whereas 73, 53, and 40% were infertile for 2, 3, and 4 y, respectively. At study termination (5 y after a single GnRH vaccine was administered), four cats (27%) remained infertile. The GnRH antibody titers declined more rapidly in short-term responding cats with < 2 y of infertility (n = 4), compared to long-term responding cats that experienced fertility control for >2 y (n = 11) (P < 0.05). Non-painful but persistent late-onset granulomatous injection site masses appeared 2 y after initial vaccination in five cats. We concluded that GnRH immunocontraception is an ideal candidate for further development for feral cat control. [Copyright &y& Elsevier]

Abstract: White-tailed deer (n =14 treated, n =7 control) were examined postmortem to identify any possible pathophysiology resulting from PZP immunocontraception vaccination. Deer were treated twice in 1997; given a booster in 1998, with six being revaccinated in September 2000. Granulomas were found at injection sites of most deer, even 2 years post-treatment. Eosinophilic oophoritis occurred in 6 of 8 (75%) deer vaccinated in 1998, and 3 of 6 (50%) revaccinated in 2000. The 2000 revaccinates without oophoritis, had significantly fewer normal secondary follicles than control females (P =0.03), and deer in the1998 treatment group (P =0.04). PZP immunocontraceptive vaccine elicited ovarian pathologies in deer similar to those observed in other species. [Copyright &y& Elsevier]

Abstract: Parenteral vaccination campaigns are integral to the elimination of canine rabies. To maximize herd immunity in dogs, immunocontraception provided at the time of rabies vaccination should reduce fecundity and dog abundance. GonaCon™ has been used successfully as an immunocontraceptive in a variety of mammals, and by inference, the dog would be an ideal candidate for testing. As an initial step in evaluating a combination-vaccination program, we assessed the effects of GonaCon™ on rabies virus neutralizing antibody production in dogs after administration of a veterinary rabies vaccine. Eighteen feral/free ranging dogs were included in this initial study: six were given GonaCon™ only, six were given rabies vaccination only, and six received GonaCon™ and rabies vaccination. Antibody levels were evaluated over 82 days. The use of the immunocontraceptive GonaCon™ did not affect the ability of dogs to seroconvert in response to the rabies vaccine. Thus, GonaCon™ provides a potential immunocontraceptive for use in combination with rabies vaccine to increase herd immunity and address dog population over abundance to better manage rabies. [Copyright &y& Elsevier]