One-year reproductive effects of anti-GnRH and rabies vaccination in female pet cats.
5 affiliations
- 1Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agricultural, Food & Environment, The Hebrew University of Jerusalem , Rehovot, Israel.
- 2Kimron Veterinary Institute, Ministry of Agriculture , Rishon Lezion, Israel.
- 3Nature & Parks Authority , Jerusalem, Israel.
- 4USDA APHIS Wildlife Services, National Wildlife Research Center , Fort Collins, Colorado, USA.
- 5Advanced Academic Programs, Krieger School of Arts and Sciences, Johns Hopkins University , Baltimore, Maryland, USA.
Abstract
Overpopulation of domestic cats poses risks to public health, biodiversity, and animal welfare. Surgical sterilization is widely used but has substantial limitations. Gonacon, an anti-GnRH vaccine, provides a nonsurgical alternative; however, data are lacking for owned queens living in natural habitats and for simultaneous vaccination against rabies. We evaluated the 1-year immunogenicity, safety, and efficacy of simultaneous Gonacon-rabies vaccination in pet queens and compared responses between indoor and outdoor cats. In a prospective field study, 36 intact queens (≥6 months) received Gonacon-rabies vaccination (Gonacon-Rabies, n = 30) or ovariohysterectomy with rabies vaccination (Ovx-Rabies, n = 6). Queens remained under their owners' care and were monitored at 0, 3, 6, and 12 months. Twenty-five queens completed the follow-up (22 Gonacon-Rabies, 3 Ovx-Rabies). Injection-site nodules were observed only following Gonacon vaccination (13.6 vs 0%; P = 0.0564). Anti-GnRH seropositivity was detected in 68.2, 31.8, and 27.3% of Gonacon-Rabies queens at 3, 6, and 12 months, respectively. Among responders (n = 15), 53.3% were positive only at 3 months, 6.7% remained positive up to 6 months, and 40% remained positive throughout the study. All Gonacon-vaccinated nonresponders were outdoor queens (outdoor: 7/13; 53.8%; indoor: 0/9; P = 0.0167). The duration of anti-GnRH immunity was shorter in outdoor queens (2.1 ± 0.9 vs 8.3 ± 1.5 months; P = 0.0005). Reproductive events (estrus or pregnancy) occurred in 76.9% of outdoor vs 11.1% of indoor Gonacon-Rabies queens (P = 0.0075). AMH concentrations were inversely correlated with anti-GnRH levels (r = -0.53; P < 0.0001). Rabies antibodies remained protective (≥0.5 IU/mL) but were lower in outdoor vs indoor queens (P = 0.0490). Owner satisfaction was higher for Gonacon-Rabies indoor queens and those without reproductive events. Simultaneous Gonacon-rabies vaccination was safe and partially effective over 1 year, with better responsiveness in indoor queens.Lay summary
Domestic cats are highly prolific, contributing to overpopulation that negatively affects animal welfare, wildlife biodiversity, and public health. Although surgical sterilization is widely used to prevent reproduction in cats, it has important practical, economic, and ethical limitations. We studied the safety, immune response, and reproductive effects of a contraceptive anti-GnRH vaccine (Gonacon) administered concurrently with a rabies vaccine in female pet cats living under normal home conditions. The combined vaccination was generally safe, and most queens maintained protective immunity against rabies. However, the contraceptive effects varied considerably among animals. Indoor queens developed stronger, longer-lasting immune responses and experienced fewer signs of estrus and fewer pregnancies than outdoor queens. In contrast, many outdoor queens showed weaker and shorter-lasting immune responses. These findings suggest that combined vaccination may provide a practical nonsurgical approach to controlling reproduction in some pet cats, but living conditions can strongly influence its effectiveness.
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BibTeX
@article{novak2026oneyear,
title = {{One-year reproductive effects of anti-GnRH and rabies vaccination in female pet cats.}},
author = {Shiri Novak and Boris Yakobson and Roni King and Lauren Jaebker and Douglas C Eckery and Tal Raz},
journal = {Reproduction \& fertility},
year = {2026},
month = oct,
doi = {10.1530/raf-26-0102},
url = {https://europepmc.org/article/MED/42832253},
note = {CC BY},
}
RIS
TY - JOUR
TI - One-year reproductive effects of anti-GnRH and rabies vaccination in female pet cats.
AU - Shiri Novak
AU - Boris Yakobson
AU - Roni King
AU - Lauren Jaebker
AU - Douglas C Eckery
AU - Tal Raz
PY - 2026
DA - 2026/10/01
JO - Reproduction & fertility
DO - 10.1530/raf-26-0102
UR - https://europepmc.org/article/MED/42832253
AB - Overpopulation of domestic cats poses risks to public health, biodiversity, and animal welfare. Surgical sterilization is widely used but has substantial limitations. Gonacon, an anti-GnRH vaccine, provides a nonsurgical alternative; however, data are lacking for owned queens living in natural habitats and for simultaneous vaccination against rabies. We evaluated the 1-year immunogenicity, safety, and efficacy of simultaneous Gonacon-rabies vaccination in pet queens and compared responses between indoor and outdoor cats. In a prospective field study, 36 intact queens (≥6 months) received Gonacon-rabies vaccination (Gonacon-Rabies, n = 30) or ovariohysterectomy with rabies vaccination (Ovx-Rabies, n = 6). Queens remained under their owners' care and were monitored at 0, 3, 6, and 12 months. Twenty-five queens completed the follow-up (22 Gonacon-Rabies, 3 Ovx-Rabies). Injection-site nodules were observed only following Gonacon vaccination (13.6 vs 0%; P = 0.0564). Anti-GnRH seropositivity was detected in 68.2, 31.8, and 27.3% of Gonacon-Rabies queens at 3, 6, and 12 months, respectively. Among responders (n = 15), 53.3% were positive only at 3 months, 6.7% remained positive up to 6 months, and 40% remained positive throughout the study. All Gonacon-vaccinated nonresponders were outdoor queens (outdoor: 7/13; 53.8%; indoor: 0/9; P = 0.0167). The duration of anti-GnRH immunity was shorter in outdoor queens (2.1 ± 0.9 vs 8.3 ± 1.5 months; P = 0.0005). Reproductive events (estrus or pregnancy) occurred in 76.9% of outdoor vs 11.1% of indoor Gonacon-Rabies queens (P = 0.0075). AMH concentrations were inversely correlated with anti-GnRH levels (r = -0.53; P < 0.0001). Rabies antibodies remained protective (≥0.5 IU/mL) but were lower in outdoor vs indoor queens (P = 0.0490). Owner satisfaction was higher for Gonacon-Rabies indoor queens and those without reproductive events. Simultaneous Gonacon-rabies vaccination was safe and partially effective over 1 year, with better responsiveness in indoor queens.Lay summary Domestic cats are highly prolific, contributing to overpopulation that negatively affects animal welfare, wildlife biodiversity, and public health. Although surgical sterilization is widely used to prevent reproduction in cats, it has important practical, economic, and ethical limitations. We studied the safety, immune response, and reproductive effects of a contraceptive anti-GnRH vaccine (Gonacon) administered concurrently with a rabies vaccine in female pet cats living under normal home conditions. The combined vaccination was generally safe, and most queens maintained protective immunity against rabies. However, the contraceptive effects varied considerably among animals. Indoor queens developed stronger, longer-lasting immune responses and experienced fewer signs of estrus and fewer pregnancies than outdoor queens. In contrast, many outdoor queens showed weaker and shorter-lasting immune responses. These findings suggest that combined vaccination may provide a practical nonsurgical approach to controlling reproduction in some pet cats, but living conditions can strongly influence its effectiveness.
SN - 2633-8386
ER -