Raccoon Strain Rabies

Raccoon-strain rabies was first diagnosed in the early 1950s in Georgia and Florida. It was not detected anywhere else except in those two states. In 1978, an outbreak of raccoon-strain rabies began in northern Virginia, probably due to the translocation of raccoons by hunters from the Georgia/Florida area. From 1978 on, raccoon-strain rabies spread along the eastern seaboard, eventually occurring from Florida to Maine. The disease then began spreading in a westerly direction across New York, Pennsylvania, and into Canada.  In 1997, the disease reached northeastern Ohio. Data for rabies cases in the United States in 1997 showed that 50 percent of all animal rabies was associated with raccoons.  Raccoons continue to be the most frequently reported rabid wildlife species.

The United States Department of Agriculture's Wildlife Services (USDA/WS) agency and affected states (including Ohio) have undertaken a comprehensive terrestrial rabies control program involving oral vaccination of raccoons. This complex and expensive program is highly regarded by the residents of affected states because of it's proactive nature.  Today, the USDA/WS and m ultiple state and local agencies continue their cooperation in maintaining an "immune barrier" spanning from Ohio, Pennsylvania and New York, intending to reach the Gulf of Mexico in Alabama in order to stop the spread of raccoon rabies. Agencies involved with this outbreak have also utilized extensive educational programs for citizens of their states and encouraged pet and livestock vaccination programs. Michigan has benefited from these efforts, as raccoon-strain rabies has not yet been detected here. 

The actual number of reported cases of rabies represents only a small percentage of the total cases that occur each year since many rabid animals are never observed and therefore remain untested. However there has been increased surveillance performed by state health departments and the USDA Wildlife Services in critical geographic areas.

BIOLOGICAL IMPACTS

Raccoons are capable of transmitting rabies, canine distemper, and parvovirus to domestic dogs and rabies and roundworms (Baylisascaris) to humans.  Disease is most prevalent in populations that become too great to be supported by available food and habitat. 

Raccoons occur in all counties in Michigan.  They are most abundant in the Lower Peninsula, particularly in the southern half, where many raccoon populations are at or approaching carrying capacity.  Population densities generally decline from the southern one third of the State to the Upper Peninsula due to habitat quality, food abundance and availability, and winter severity.  Densities reported in the literature range from one raccoon per acre to one per 150 acres.  High densities are usually found along river bottoms or agricultural areas that are well interspersed with woodlands and waterways, and range from one animal per 10 acres to one per 16 acres.  Lower population densities are typical of evergreen forests.  In residential areas where food may be abundant and cover is plentiful, raccoons may approach even greater densities. 

Raccoons have few natural predators.  Therefore, hunters and trappers have been the primary means of population control.  There are an estimated 2-3 million raccoons in Michigan at the time that hunting and trapping seasons begin each year.  Statewide management goals are directed toward maintaining current levels of raccoon harvests.  Hunters and trappers have harvested 200,000-300,000 animals annually during the past decade. Raccoon hunting with hounds is very popular in Michigan. Raccoon hunters take approximately two-thirds of the raccoons harvested in Michigan each year. Trappers also harvest thousands of raccoons annually by using a variety of traps and trapping techniques. Many raccoons are killed by vehicles while crossing highways, particularly in the spring when young disperse, and males search for mates.

This page is maintained by the Michigan Department of Natural Resources