Rabies

Feral Cats and Effective Rabies Control

Rabies is an acute viral infection of the central nervous system. Of all the zoonotic diseases, it is one of the most feared and misunderstood even though its threat to humans is very small in the U.S. Although there is a low incidence of rabies among the human population, the virus causes acute encephalitis and is invariably a fatal disease. Media accounts tend to sensationalize and reinforce popular misconceptions about rabies. Much unnecessary anxiety and fear could be avoided by understanding that rabies in the U.S. is primarily a disease of wildlife, that the disease can be controlled, and that the threat to humans and companion animals can be minimized. In Asia and Africa, animal rabies is found primarily in dogs. The disease usually infects humans through a bite from a rabid animal.

For the past 40 years rabies has been reported more frequently in wildlife than in domestic animals. According to the Centers for Disease Control (CDC), 49 states, the District of Columbia, and Puerto Rico reported 7,967 cases of rabies in animals in 2002. Three humans contracted rabies. One had killed a bat in his home, although during treatment he denied that he had had any contact with a bat. Another teenager had released a bat into the woods, and died of bat rabies 2 weeks later. A third man had been bitten by a dog twelve days before being admitted to hospital with rabies symptoms. The dog was ruled out as a possible cause. The man died from the bat rabies variant.

The total number of reported cases in the contiguous United States increased by 7.2% from the 7,436 cases in animals and one in a human in 2001.

Wildlife managers, public health officers, animal agencies, and the animal protection community face important decisions on how to control this disease. All too often, feral cats are caught in the middle of well-meaning but ill-conceived efforts to protect humans by exterminating healthy feral and stray animals. Efforts to eliminate rabies by killing animals are not only cruel, but also are ineffective, costly, and difficult to implement. Nonlethal control has proven to be more effective over the long term.

Research has shown that population reduction often causes wildlife populations to expand rather than decline, as the remaining animals will quickly breed to the previous numbers. Others will enter from different areas, and these may not have the immunity of local populations. Scientific evidence confirms the long-term viability of nonlethal population and disease control through sterilization, birth control, and oral vaccines for wildlife. These methods represent a more humane and effective approach to the prevention of rabies.

What To Do If You Are Bitten

All animal bites should be immediately flushed and cleansed with soap and water. Wash the wound for five minutes – this is very important. Unfortunately, bites from bats are difficult to detect. Rabies is treatable through effective post-exposure treatment that must be started before symptoms appear.

First and most important – use the correct equipment – do not pick up feral kittens until you have tamed them. If the bite becomes infected see a doctor or go to the emergency room for antibiotics – cat bites can become infected very quickly. Keep the cat confined for 2 weeks. Rabies quarantine is essential and rabid cats usually die within 4 to 6 days.

Make sure your tetanus vaccination is current. This vaccination lasts for ten years, but each time you are bitten, its potency is depleted.

If you are trapping ferals, you should have the preexposure rabies shots. These are available from your local Department of Public Health. The series of 3 injections usually costs $50 each – maybe more, depending on your area.

If an unknown animal has bitten you and the animal cannot be quarantined, you will need post-exposure shots. You will need: one dose of immune globulin, then 5 doses of rabies vaccine over a 28 day period (days 0,3,7,14,28) after the first vaccination. The shots in the arm are almost painless – the shots previously administrated in the stomach are no longer given!

Rabies and Wildlife

Rabies has been a part of wildlife ecology since prehistoric times and is present throughout the world with the exception of Antarctica, Australia, Britain, and islands such as Hawaii. The primary carriers in the U.S. (in descending order) are raccoons, skunks, bats, and foxes. Infection is nearly non-existent in rodent populations. Around 93 percent of rabies in animals is found in wildlife and several distinct virus variants have been identified.

Within wildlife populations the disease usually follows a self-limiting pattern. The outbreak of an epidemic is characterized by a peak that stabilizes and then declines over a cycle of approximately five years. Increased population immunity follows infection, thus limiting further outbreaks.

During the progression of the disease, infected animals exhibit behavioral changes such as restlessness, excitability, and severe aggression, often attacking and biting any approaching animal or human. Wildlife seen during the day, seemingly unafraid of humans, or displaying strange behavior, should be suspected of being rabid. Do not attempt to approach or handle these animals. Carefully back away and immediately report the incident to local animal or public health officials.

The main response to rabies control in the U.S. in the past has been to try to reduce the vector species by killing groups of animals. This effort has proven totally ineffective, hastening the spread of the disease by removing healthy animals and thus creating territorial “vacuums” for other animals of those species to enter.

Rabies in U.S. Border Countries

In 2002 Canada reported 343 cases of rabies in animals, a 21.6% decrease from 445 in 2001. Rabies in skunks decreased during 2002, though rabies in bats accounted for 32.1%, an increase of 8.7%. Canada reported no cases in humans.

Mexico reported 331 cases of rabies in animals, a decrease of 6.5% from 2001. Dogs accounted for 31.7% of rabies cases. This was a decrease from 523 in 1997. Mexico confirmed 2 cases of rabies in humans, the source: bats.

This, however, was a decrease from 1997 when 23 people contracted rabies in Mexico.

Lethal Solutions Vs. Nonlethal Solutions

In Western Europe, the very successful oral vaccine (vaccinia-glycoprotein—V-RG) developed in the U.S., has proven to be an effective, economical, and humane control for rabies. Wildlife vaccination via food bait has blocked the spread of the disease and prevented small outbreaks from becoming major epidemics by maintaining healthy populations of key vector species as immune barriers.

Vaccines placed in baits ensure very high immunization rates. Field tests on over 40 species of animals have demonstrated the vaccine’s safety.

Scientific experts stated long ago that killing populations to control rabies might actually aggravate the spread of the disease. In 1973, The National Academy of Sciences stated: "Persistent trapping or poisoning campaigns as a means to rabies control should be abolished. There is no evidence that these costly programs reduce either wildlife reservoirs or rabies incidence."

Unfortunately, many government agencies and conservation groups took a long time to grasp this concept, and millions of animals needlessly lost their lives.

Finally, in 1997, veterinarians and wildlife biologists at the Cornell University College of Veterinary Medicine stated that vaccination barrier zones could halt the spread of raccoon rabies.

Cornell’s Dr. Donald Lein called for congressional action to appropriate funds through the government’s Animal Damage Control (ADC) unit of the USDA-APHIS, to use for oral vaccination programs.

The V-RG vaccine has been used in several "drops" across parts of the eastern U.S. for raccoons and in Texas for coyotes and gray foxes. Approximately 355,000 doses of the vaccine were distributed over 1,500 square miles in four counties in Ohio in 1998. Since the programs were initiated, a total of 8.6 million doses of the vaccine have been distributed over 140,000 square miles. So far the results have been excellent, with markedly reduced rabies cases reported in the targeted areas.

Solution for the U.S.: Kill the Virus, NOT the Animals

Rabies can be controlled and its threat to human health minimized. Local, state, and federal agencies responsible for wildlife management and public health have been reluctant to adopt nonlethal disease control alternatives in the past. This has resulted in the spread of rabies, the deaths of countless animals, and a needless risk to human health.

Other states are now using vaccine-laced bait: Ohio, Florida (Pinellas County), Massachusetts (Cape Cod), New Jersey (Cape May), New York (upstate), Vermont, and parts of Texas. The Texas Department of Health originally hoped that the oral vaccine would only contain the rabies virus in animals. They now believe that the vaccine appears to eliminate rabies over large areas.

During 2002 multiple state agencies, the CDC and the USDA, continued to expand an immune barrier from Lake Erie, PA and New York that will eventually reach the Gulf of Mexico in Alabama.

Other Countries

Many countries in Western Europe have eliminated rabies by using the oral vaccine. This has caused the World Health Organization (WHO) to state that rabies can eventually be eradicated worldwide. This is indeed good news for many developing countries. India and parts of Africa still have thousands of people dying from rabies each year. WHO reports that between 35,000 and 60,000 people die annually from rabies. Most of the cases are found in Asia, but Africa has a large number of rabies cases as well. Because it is very difficult to collect data in poorer countries, many rabies deaths go unreported.

Bat Rabies

Rabies acquired from bats has been the main cause of rabies deaths in humans in the U.S. Even then this incidence is very low—just a few each year.

During the last century, the number of human deaths in the U.S.attributed to rabies decreased from 100 or more per year to an average of one to two each year.

It has not always been clear how humans acquire rabies from bats. In many cases the fact that those people who died from rabies had contact with a bat was established only after the death of the person. It may be that the bite wounds are so small that they have not been noticed.

As a precaution, if anyone ever encounters a sick bat, you should call a wildlife rehab. center for advice and do not handle the bat. If a bat dies or bites a human, rabies tests should be done immediately on the bat. If rabies is confirmed, post-exposure treatment should be started right away.

Remember that bats are a vital part of the environment. A lot of misinformation and many myths surround bats. For instance, they will not get tangled in your hair! They are one of the most beneficial creatures on earth. They help to keep diseases down by consuming vast quantities of insects, and for this alone they should be treated with a great deal of respect. The number of rabid bats found is indeed very small.

Feral Cats and Rabies

First, no cat has infected a human with rabies for over 4 decades.

Cats are less susceptible to rabies than many other animals. When cats do get rabies, they usually get the "furious" type; they stop eating, become very aggressive, and make unprovoked attacks on other animals and humans. Rabid cats usually die within four to eight days.

Generally the CDC recommends 10-day rabies quarantine for cats. Some health departments, such as the one in Maryland, insist on a six-month quarantine.

Although not natural vectors of rabies, feral cats can become exposed to the virus by attacks from infected wildlife. Since ferals often live in close proximity to humans and wildlife, animal control officials may try to eliminate colonies in ill-conceived efforts to control the disease to protect human health. However, if colonies are destroyed, other cats soon move in to fill the vacated territory.

The best means to protect both feral cats and human health is to vaccinate all cats and maintain up-to-date, accurate records.

This solution requires legislators, regulatory agencies, public health departments, wildlife managers, and animal control personnel to become educated about the advantages, effectiveness, and necessity of implementing this safe, ecologically sound, and humane response to the rabies epidemic.

Even though much is made of the fact that more rabid cats are found in the U.S. now than rabid dogs, still the figures are very low – 300 rabid cats in 1997. Cats are not considered a vector species. There is no "cat" rabies. Rabid cats are reported by states experiencing epizootics of rabies in raccoons, followed by states with rabid skunks and finally by states with rabid foxes.

2003 Human Rabies Update

During the first 9 months of 2003, 3 humans in the U. S. contracted rabies, and one person in Canada. The Canadian man died from rabies caused by a bat. A 25-year-old man in Fairfax County, Virginia, died from rabies in March. This rabies infection was found to be the Raccoon variant, the first time that has ever happened in the country. No exposure to a rabid raccoon, or any history of an animal bite could be found. In June a Puerto Rican died from rabies caused by the dog/mongoose type. He had been bitten by a dog. And in September a man died in California from rabies contracted from a bat. A bat had bitten the man 6 weeks earlier.

Since 1990 thirty-eight people have died in the U.S. from rabies. Thirty-one of these cases were caused by rabies indigenous to the U.S. –29 by bats. The other 8 cases were people who acquired rabies outside of the country.

The History of Rabies in the U.S.

Ellen Perry Berkeley, in her article "The Truth about Rabies" in I Love Cats magazine, shares this interesting synopsis of rabies in the United States:

Comprehensive nonlethal Rabies control program based on three primary initiatives:

  1. Implement widespread oral-vaccine immunization barriers for key wildlife vector species, primarily raccoons and skunks.
  2. Educate the public on steps to minimize human risk from wildlife rabies, including vaccination of outdoor cats and dogs and reporting sick bats to wildlife groups—bats are not to be killed.
  3. Recognize and support the vaccination and nonlethal management of feral cat colonies as an effective and important part of a comprehensive control program.

Preventing Rabies in Feral Cats

The most effective means of stabilizing and reducing populations, controlling rabies, and protecting human health, is to sterilize and return healthy vaccinated cats back to their supervised colonies. This helps to reduce roaming for mates, searching for food, and fighting. Vaccinated colonies also act as a buffer zone between humans and wildlife.

In areas where rabies remains endemic, colony management may require retrapping for periodic booster vaccinations. Two other steps are crucial to the enterprise: individual members of the colony must be made recognizable in the future by an immediate ear-tipping of the left ear, and colony health must be monitored by continued supervision of all colony members.

Finally, pre-exposure rabies vaccinations are vital for all those who handle feral cats: veterinarians, technicians, animal control officers, and those involved in trapping. Call your local health department for information on how to obtain the vaccination.

Further measures for colonies in areas where rabies has occurred include feeding only during the day and providing only enough food for immediate consumption. This minimizes contact with nocturnal wildlife.

Feeding areas should be kept clean and, where possible, other nearby food sources should be eliminated.

More Rabies Facts

Since 1990, 38 people have died in the U.S. from rabies. Thirty-one caused by bats. The World Health Organization reports that approximately 50,000 to 60,000 humans die from rabies each year worldwide.

Frequent rabies boosters in cats can cause fibrosarcomas that can be fatal. Therefore annual rabies vaccinations are no longer recommended. A three-year vaccination plan is now advocated.

After vaccinating domestic cats, it is normal for a lump to appear at the injection site for a few days. However, you should check the vaccination site for lumps a few weeks later, and if one appears at that time, report this to your veterinarian immediately.

If anyone comes into contact with a sick bat, it is strongly recommended that a quarantine or rabies test be considered for the bat. Only 3 of the 29 cases of people who died from the bat rabies variants showed any bite wounds. This may be because the wound left by a bat is very small. Remember that bats are beneficial to the environment and they keep insects under control. Many bat populations are endangered. There would be far more diseases if bats were exterminated. Cats with rabies usually die within four to eight days, thus a quarantine period of two weeks, as recommended by the CDC, is usually adequate.

Pre-exposure rabies vaccinations are available from your local Department of Public Health. The series of three injections usually costs $50 each, depending on the area. Post-exposure shots: one dose of immune globulin, then five doses of rabies vaccine over a 28-day period after the first vaccination (days 0,3,7,14,28). The shots are now given in the arm—shots in the abdomen have been discontinued.

The National Academy of Sciences stated as long ago as 1973 that: "Persistent trapping or poisoning as a means to rabies control should be abolished. There is no evidence that these costly programs reduce either wildlife reservoirs or rabies incidence. The money can be better spent on research, vaccination, compensation to stockmen for losses, education, and warning systems."

Minimize Your Risk

If you feed feral colonies, remove food sources after dark:

Need for Education

The wildlife rabies epidemic can effectively be controlled and represents a very minor threat to public health. And this minor threat can be further minimized with a few simple precautions, mentioned in this article.

According to the CDC, long-term lethal control (sustainable population reduction) has not been successful in North America or elsewhere.

What You Can Do

Contact state and federal agencies responsible for wildlife management and public health, encouraging immediate implementation of comprehensive nonlethal wildlife rabies control programs using the V-RG oral vaccine.

These agencies include: state game commissions, local animal control authorities, and federal, state, and local health departments.

Field programs in Europe and Canada using oral vaccines have had promising results. Switzerland was declared rabies-free status in 1998, after using oral vaccinations in wildlife populations. France is close to being rabies free. Southern Ontario is close to eliminating rabies in red foxes. In Texas, the oral vaccine is showing great promise in eliminating rabies in gray foxes and coyotes. For the first time, through the use of oral immunization, a method for the elimination of rabies is available that is effective, safe, inexpensive, and practical.

L.G. Schneider, World Health Organization Center for Rabies Surveillance and Research

Bibliography:

"U.S. Rabies ‘Experts’ Need A Dose of Own Medicine," by Bill Clark, Action Line, the Friends of Animals , Winter 1992.

"Control of Rabies in Wildlife," by William Winkler and Konrad Bogel, Scientific American, June 1992.

Booklet on Wildlife Rabies, published by the Wistar Institute–Philadelphia, PA

"Rabies Surveillance in the United States during 1997," Journal of the American Veterinary Medical Association (JAVMA), Vol. 213, No. 12, Dec 15, 1998.

"The Truth About Rabies,"by Ellen Perry Berkeley, I Love Cats, March/April 1995.

"Rabies surveillance in the U.S. during 2002," by John W. Krebs, MS; John T. Wheeling, BS; James E. Childs, ScD . JAVMA, Vol 223, No12, December 15, 2003

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