Contact Information: 

Dr. Douglas Eckery

NWRC Headquarters

4101 LaPorte Avenue 

Fort Collins, CO 80521

Phone: (970) 266-6164

FAX: (970) 266-6157

douglas.c.eckery@aphis.usda.gov

www.aphis.usda.gov/wildlife_damage/

nwrc/

Major Cooperators:

• Australia’s Invasive Animal 

Cooperative Research Centre

• Colorado State University

• Florida Department of Agriculture 

and Consumer Services

• Florida Power and Light Company

• Innolytics, LLC

• National Park Service

• United Kingdom’s Food and 

Agricultural Research Agency

• U.S. Air Force (Avon Park, Florida)

• University of Pittsburg

Wildlife Services

Protecting People rotecting People

Protecting Agriculture rotecting Agriculture

Protecting Wildlife rotecting Wildlife

FY 2012

National Wildlife Research Center

United States Department of Agriculture

Animal and Plant Health Inspection Service

National Wildlife Research Center Scientists Study Wildlife Contraception

Wildlife Services’ (WS) National Wildlife Research Center (NWRC) is the only Federal 

research organization devoted exclusively to resolving confl icts between people and 

wildlife through the development of effective, selective, and socially responsible methods, 

tools, and techniques.

Research on the reproductive management of various avian and mammalian species 

that cause damage or threaten public health and safety is a high priority for WS. The 

severity of human-wildlife confl icts often is directly related to wildlife population density; 

many problems are exacerbated as wildlife populations become larger. In many urban and 

suburban settings, for example, overabundant deer create safety hazards for motorists, 

consume ornamental shrubs, harbor and transmit diseases and parasites (e.g., Lymedisease-bearing ticks), and degrade habitat quality in public parks and other locations. 

Rodents carry a variety of diseases (e.g., plague, hantavirus) and damage rangelands and 

crops, resulting in the loss of millions of dollars in agricultural production. Overabundant 

feral horses in several western states degrade the quality of the habitat and create 

ecological and political problems. Stray dogs in many countries pose a potential public 

health risk, primarily due to bite injuries and the spread of rabies. 

The goal of NWRC’s wildlife contraceptive research is to develop injectable and oral 

contraceptives to manage overabundant wildlife populations. In 2009, APHIS successfully 

registered with the U.S. Environmental Protection Agency the fi rst immunocontraceptive 

vaccine for wildlife. The single-shot, multi-year vaccine called GonaConTM 

Immunocontraceptive Vaccine (GonaCon) was initially registered for use in female whitetailed deer, especially in urban and suburban areas where traditional lethal options are 

limited. Research has shown GonaCon to be an effective reproductive inhibitor in many 

other mammal species including elk, feral horses, bison, prairie dogs, ground squirrels, 

and feral dogs, and cats. Future NWRC research with GonaCon likely will involve studies 

to support expanded registration to other species, to develop oral delivery systems, and 

to prevent transmission of wildlife diseases. Wildlife contraceptives, such as GonaCon, 

can be used in conjunction with other tools in an integrated program to manage local, 

overabundant wildlife species.

Applying Science and Expertise to Wildlife Challenges

Use of GonaCon on Wild Horses—Overpopulation of wild horses and burros is a 

signifi cant concern in the Unites States, as these animals can overgraze native plant 

species and compete with livestock and local wildlife for food and habitat. The Bureau 

of Land Management (BLM) estimates that approximately 31,500 horses and 5,800 

burros are roaming on BLM-managed rangelands in 10 Western States. The estimated 

current free-roaming population exceeds by nearly 11,000 the number that the BLM has 

determined can exist in balance with other public rangeland resources and uses. Current 

management options are limited with the majority of actions involving the removal of 

horses and burros from the range and either putting them up for adoption or holding them 

indefi nitely in captivity. Wildlife offi cials need additional nonlethal methods to manage 

populations of wild horses. Administering immunocontraceptive vaccines to control 

the fertility of free-ranging horses is a potential option to manage overabundant local 

populations. In January 2013, GonaCon’s registration was expanded to include its use to 

manage fertility in wild and feral horses and burros. The vaccine is available for use by 

employees of APHIS’ WS and Veterinary Services programs, the U.S. Bureau of Land 

Management, the U.S. Fish and Wildlife Service, the U.S. National Park Service, the U.S. 

Department of Defense, Federally-recognized Indian tribes, State agencies responsible for 

wild or feral horse and burro management, public and private wild horse sanctuaries, or 

persons working under their authority. Delivery of the product is by hand injection, jab stick, 

or darting.

Contraceptive Technologies for Use in Wildlife ontraceptive Technologies for Use in Wildlife 

Population and Disease Management opulation and Disease Management 

Groups Affected by These Problems:

• Airports, airlines, airline passengers

• Electric utility companies

• Farmers 

• Landscapers

• Motorists, pedestrians

• Natural resource managers

• Pet owners

• Ranchers/Livestock producers

• Urban and suburban residents
Experimental Use Permit for GonaCon in Bison—Preliminary 

laboratory data indicate that GonaCon not only is an effective 

contraceptive in bison, but also potentially retards the spread of 

brucellosis, an infectious disease that affects bison, elk, cattle, 

and many other mammals. Consequently, WS and Veterinary 

Services initiated a joint fi eld study in southern Colorado to 

evaluate the contraceptive effi cacy and duration of GonaCon 

in bison under free-ranging conditions. The study complements 

an ongoing study in Montana that tests GonaCon as a means 

of slowing the spread of brucellosis in bison. If these studies 

demonstrate that GonaCon is effective in bison, APHIS will likely 

pursue a product registration from EPA.

Combined Rabies-Contraceptive Vaccines for Raccoons—

NWRC scientists conducted preliminary tests to evaluate the 

feasibility of a combined rabies-GonaCon vaccine for use 

in raccoons. WS operations biologists vaccinate hundreds 

of raccoons and other medium-sized mammals annually in 

response to localized rabies outbreaks. However, in areas 

where raccoon populations are high, the risk remains high that 

rabies will continue due to the production of susceptible young. 

NWRC scientists investigated whether immunocontraception 

is feasible for controlling raccoon population densities while 

sustaining a high immune status within adult populations in 

urban areas where the risk of rabies is high. Thirty-two raccoons 

were inoculated with either GonaCon, the rabies vaccine 

IMRAB® or both vaccines to simulate trap-vaccinate-release 

procedures used by the WS Oral Rabies Vaccination Program. 

Results show GonaCon prevents pregnancy in raccoons without 

interfering with the development of rabies antibodies stimulated 

by IMRAB®. To comply with registration requirements, NWRC 

scientists are conducting a breeding experiment as a second 

method to evaluate the contraceptive. They also plan to evaluate 

if GonaCon is as effective in young-of-the-year raccoons as it 

appears to be in adult raccoons.

GonaCon Use in Black-Tailed Prairie Dogs—Management 

of prairie dogs includes toxicants, fumigants, barriers, and 

relocation. Nonlethal methods that allow the existence of 

prairie dogs but help to minimize damage related to population 

growth are preferred, especially in urban and suburban areas. 

Researchers evaluated the immune responses and health 

effects of captive and wild black-tailed prairie dogs injected with 

GonaCon vaccine. No adverse effects of GonaCon were noted 

on the animals’ weight or blood chemistry. The antibody titers 

recorded in the animals indicate that GonaCon has the potential 

to contracept prairie dogs for 1 year or more in the fi eld.

Selected Publications:

GIONFRIDDO, J. P., A. J. DENICOLA, and K. A. FAGERSTONE. 

2011. Effi cacy of GnRH immunocontraception of wild white-tailed 

deer in New Jersey. Wildlife Society Bulletin 35:142-148. 

GIONFRIDDO, J. P., A. J. DENICOLA, L. A. MILLER, and K. A. 

FAGERSTONE. 2011. Health effects of GnRH immunocontraception of wild white-tailed deer in New Jersey. Wildlife Society Bulletin 35:149-160. 

LEVY, J. K., J. A. FRIARY, L. A. MILLER, S. J. TUCKER, and 

K. A. FAGERSTONE. 2011. Long-term fertility control in female 

cats with GonaConTM, a GnRH immunocontraceptive. 

Theriogenology 76:1517-1525.

MASSEI, G., D. P. COWAN, J. COATS, F. BELLAMY, R. QUY, 

S. PIETRAVALLE, M. BRASH, and L.A. MILLER. 2012. Longterm effects of immunocontraception on wild boar fertility, 

physiology and behaviour. Wildlife Research 39:378-385.

SANDERS, D. L., F. XIE, R. E. MAULDIN, J. C. HURLEY, L. A. 

MILLER, M. R. GARCIA, R. W. DEYOUNG, D. B. LONG, and 

T. A. CAMPBELL. 2011. Effi cacy of ERL-4221 as an ovotoxin 

for feral pigs (Sus scrofa). Wildlife Research 38:168-172. 

YODER, C. A., B. A. MAYLE, C. A. FURCOLOW, D. P. 

COWAN, and K. A. FAGERSTONE. 2011. Feeding of grey 

squirrels (Sciurus carolinensis) with the contraceptive agent 

DiazaCon tm: effect on cholesterol, hematology, and blood 

chemistry. Integrative Zoology 6:409-419. 

YODER, C. A., and L. A. MILLER. 2010. Effect of GonaConTM

vaccine on black-tailed prairie dogs: immune response and 

health effects. Vaccine 29:233-239. 

The U.S. Department of Agriculture is an equal opportunity employment provider and employer

Major Research Accomplishments:

 APHIS was granted an EPA registration for the use 

of the GonaConTM Immunocontraceptive Vaccine to 

manage fertility in wild and feral horses and burros. 

WS continues to conduct research to expand the 

vaccine’s registration to other species. 

 WS is investigating the use of GonaCon in conjunction 

with the rabies vaccine on raccoons and feral or 

stray dogs. The immunocontraceptive could reduce 

populations of these animals in certain areas, thus, 

decreasing the potential spread of the disease. 

 WS requested an Experimental Use Permit from 

the EPA to conduct contraceptive research on freeroaming dogs on tribal reservations in the United 

States.

 WS found GonaCon to be effective at reducing fertility 

in black-tailed prairie dogs.