| Since its founding in 1984 the Ohio Wildlife Center has: • Treated over 50,000 injured or orphaned wildlife, • Provided educational experiences to 950,000 children and adults, • Responded to over 550,000 wildlife hotline calls. This has all been made possible by the donation of 500,000 hours of dedicated volunteer work. |
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Wildlife Research - Rabies Revisited Donald Burton, DVM Rabies is an ancient curse dating back to 2300 B.C. when it was described as a fatal disease acquired by humans from the bite of a mad dog. Fear and superstition have fueled some of the most fantastic stories and misperceptions surrounding rabies. Many of these stories concern the clinical signs common to humans with terminal rabies. Symptoms include: severe pain in the bite area; difficulty swallowing, especially with fluids (hydrophobia); restlessness; muscle spasms; convulsions; coma and death. Bizarre behavior associated with agitation, aggression, and crying and shouting all day and night, have been reported. In the United States, rabies has historically been associated with dogs until the early 1960's. Humans were commonly exposed by their close association with their canine companions. Upon development of effective rabies vaccine protocol for pets combined with local leash laws, canine rabies has been largely controlled. As the number of domestic animal cases began to decline, there began a rise in the reported cases of rabies in wildlife species. Since 1976, greater than 85% of all rabies cases reported have been found in wild animals. In the 1990's, greater than 92% of all cases occurred in wildlife. The principal reservoirs are skunks, raccoons, bats, and foxes. Raccoons emerged as a common host starting in 1979 as the Mid-Atlantic states rabies epizootic was beginning to be recognized. The first case of raccoon rabies outside the southeastern endemic zone was reported from West Virginia near the Virginia state line in 1977. More than three thousand raccoons captured in southeastern states and transported to Mid-Atlantic states for recreational hunting purposes are thought to have first introduced rabies into this new area. Rabies has spread from this epicenter northward at the rate of more than 25 miles per year. Rabies was first confirmed in New York in 1990 and since then 7851 animal cases have been identified (6637 in raccoons). The Mid-Atlantic state rabies epizootic spread southward and converged with the southeastern states epizootic in North Carolina in early 1995, forming a continuous east coast raccoon rabies infected area. Ohio was protected to some extent by geographic barriers, to our south by the Ohio River, and on our eastern border, the Allegheny mountain range. Ohio has only recently recognized confirmed rabies cases in raccoons. In May 1996, one raccoon and one cat were the first indigenous cases of rabies confirmed near the village of Poland in northeastern Ohio. On April 5, 1997, raccoon rabies was again confirmed in Poland, Ohio. Since then and continuing into September 1997, 51 raccoons, 2 cats, and a skunk have been found positive for raccoon rabies in Trumball, Mahoning, and Columbiana counties. This cluster of raccoon rabies cases has prompted swift response from a number of local, county, state and federal health agencies, as well as the Ohio Division of Wildlife. Currently, state and local health agencies have initiated a rabies prevention protocol utilizing enhanced active surveillance for raccoon rabies, promoting public awareness through education programs, advocating rabies immunizations of pet dogs and cats, and distributing an oral vaccination, Raboral (Rhone Merieux), to immunize wild raccoons. Vaccines have been distributed over 695 square miles by helicopter and by hand through vehicle transported ground teams into areas judged as raccoon populated. A total of 101,309 vaccine baits were distributed with 78,277 by hand and 20,880 by helicopter. In a post vaccine dispersal study, 34.5% of raccoons randomly trapped and blood tested, demonstrated rabies serum neutralizing antibodies, indicative of vaccine bait consumption. Vaccine bait distribution continued this fall with a proposed 250,000 being distributed over 1,150 square miles. This was done as an effort to create an immune barrier approximately 10 miles wide, extending from Lake Erie on the north to the Ohio River. Further vaccine distribution is planned for spring of 1998. Together with raccoon rabies, cases of bat rabies have generated a great deal of media exposure, especially in the Columbus and central Ohio area. To date, 34 documented cases of rabies have been diagnosed in bats statewide. In the Columbus, Ohio area, cases of bat rabies have been documented in pairs in the Upper Arlington, Reynoldsburg, and west side Columbus areas. Each time, the media coverage has fueled what may be termed irrational public fears. At least one case, fumigation and extermination of a local bat colony in an unoccupied residential home, was followed by subsequent building demolition. Bat rabies was first recognized in Florida, in 1953. Since then, bats have been found rabies positive in 31 of 43 species in all of the contiguous lower 48 states. Unlike most hosts, infected bats rarely demonstrate clinical signs of aggression, but instead become paralyzed. Additionally, colonies do not experience outbreaks as many terrestrial species do. Usually, only one in one thousand bats becomes infected with rabies. Despite previous reports, bats do not become healthy infected carriers. Rabid bats may show abnormal behavior such as activity during daylight hours, paralysis, or become grounded. Transmission of rabies from an infected bat to a human occurs usually as the result of a bite. Under exceptional circumstances, in a bat cave, bat rabies was highly suspected of being transmitted through an aerosol mode to humans, and has been proven in laboratory animal studies. It is very rare to contract rabies by merely entering a bat roost, unless direct contact with an infected bat occurs. The best advice to home owners in the prevention of bat rabies, is not to handle bats and to keep their homes in good repair by caulking and plugging cracks or holes greater than one quarter inch. Bats can be effectively excluded by good building maintenance. If a bat enters a home and it is certain it has not had direct contact with humans or pets, it can be released outside by opening doors and windows, and encouraging the bat to leave passively. If that fails, with gloved hands, using a coffee can, or similar container, cover the bat while sliding cardboard under the can as a lid; the bat can be captured and released outside. Other methods employing a one way bat check-valve, allowing bats to leave with no re-entry can help evict bats from an attic or other area, after plugging all but one of the entry ports. This process should only be used outside of the breeding season, which extends from May to August. Widespread or local bat roost extermination or killing is unnecessary, ecologically unsound, inhumane as well as ineffective. As long as the habitat remains unchanged, bats will find their way back. Because bat bites are more difficult to recognize than bites of larger animals, post exposure treatment should be considered for any physical contact with a bat when a bite, scratch or contamination of any open wound or mucous membrane (eye, nose, or mouth) cannot be ruled out. when possible, the offending bat should be collected without damaging its head and submitted to the Ohio Department of Health (ODH) for rabies testing. If the testing results are positive or the bat cannot be captured and brought to the ODH laboratory, post exposure treatment should be administered. Rabies is a disease which has been known for thousands of years and continues to evade total eradication. Wildlife have become and probably will continue to be the primary reservoirs for maintaining the rabies virus. With continued surveillance, wide-scale rabies vaccination of high-risk individuals, effective wound management and post exposure prophylaxis along with common sense, the actual threat of becoming infected with rabies is very small. However, those of us who handle potential rabies vector species, should continue to respect the possibility of rabies in the next animal admitted. Reference: Raccoon Rabies Update, September 1997, ODH, Kathleen Smith, DVM
Clinical Signs in Raccoons with Rabies/Canine Distemper The clinical signs of raccoons infected with rabies virus or canine distemper virus must be considered indistinguishable as both diseases are progressive debilitating neurological diseases. The range of clinical manifestation can include literally no overt or obvious signs to convulsions, coma, and death. The terminal signs are so incapacitating that they render the animal unable to resist any restraint effort. The gamut of signs proceeding the terminal events may appear as increased aggression (33 - 47%), lack of fear of humans, wandering into open garages, buildings, etc. and inability to find a way out, increased wondering, activity in daytime hours, increased probability of hit by car (3-6%), turning whole body in tight circles, self mutilation, chewing limbs and feet or scratching head and signs of face, dullness, lethargy, ataxia, uncoordinated, paralysis, inability to climb, attempts to lead to falling, and / or increased salivation. 1997 Ohio Rabies
The dramatic decrease in the number of positive raccoons in the last few months of the year indicates that the ODH vaccine bait program is effective. 
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