The Danger of Rabies
Rabies is one of the best known of all the viruses. Rabies is a disease (caused by the rabies virus) primarily of animals, including both wild and domestic animals and human beings.
Iin the U.S. rabies today is more likely to be found in cats then in dogs!
Rabies is a disease caused by a virus found in the saliva of infected animals and is transmitted to pets and humans by bites, or possibly by contamination of an open cut. Treatment of an infected person as critical. Untreated, rabies causes a painful death.
Most animals can be infected by the virus and can transmit the disease to man. Infected bats, raccoons, foxes, skunks, dogs or cats provide the greatest risk to humans. Rabies may also spread through exposure to infected domestic farm animals, groundhogs , weasels and other wild carnivores. Squirrels, rodents and rabbits are seldom infected.
Cats, dogs and cattle account for nearly 90 percent of rabies cases in domestic animals, with horses, mules, sheep, goats and ferrets making up the remaining cases. Among wild animals, the disease is most often reported in skunks and raccoons. Other wild species in this country in which rabies is commonly found include bats, foxes, and rodents.
The rabies virus, present in the saliva of an infected animal, is usually spread by a bite or scratch that punctures the victim's skin. The virus has a strong affinity for cells of the nervous system. It enters nerve cells at the site of the wound, travels to the brain, and then follows other nerve pathways to muscles and organs that are especially affected by rabies.
There are at least two other ways in which humans have been known to have contracted rabies, both extremely rare. Two people were exposed by breathing the air in caves inhabited by rabid bats. And six people contracted rabies following implants of corneas from donors who had undiagnosed rabies. The virus concentrates in the salivary glands, which explains why it is usually spread by bites. It also invades and damages the muscles involved in drinking and swallowing. Most human victims, and apparently lower animals as well, suffer excruciating pain on swallowing liquids. Though they suffer from thirst, animal and human rabies victims can be terrified by the sight of water, hence another name for the disease, hydrophobia.
|In the United States, the mountain states have the lowest incidence of humans contacting animals with rabies. When you hit the Plains, the Midwest, and Texas the striped skunk is the big carrier. As you work your way to the east, raccoons become important carriers. Fox and bats also cause some human exposures, but very rarely, especially the bat who gets blamed more than it should. If the squirrel or rabbit in the back yard bites you, do not panic, there has never been a reported case of someone contracting rabies from one of these species.|
Who is at risk?
People that work closely with wildlife, veterinarians, and travelers are at the highest risk of exposure. Fortunately, there is a vaccine that is available to protect high-risk people. Animals that come into contact with wildlife and are not vaccinated are at a higher risk of infection. While the risk of coming into contact with the virus is very low, it nevertheless does exist.
Transmission of the disease
The transmission of the disease almost always occurs as a result of an infected animal biting a non-infected animal. There have been a few reported cases of infection resulting from aerosolization occurring in caves where large quantities of infected bats reside. Rabies virus does not live very long outside the host and remains viable in the carcass of an infected animal for less than 24 hours. The rabies virus is shed at high levels in saliva. However, being bitten by a rabid animal does not necessarily mean that the bitten animal (or human) will become infected. It has been speculated, that only around 15% of exposed people will contract the disease. Humans, cats, and dogs are only mildly susceptible to the disease unlike skunks, raccoons, foxes, and bats that are much more susceptible to the virus.
After coming in contact with the virus, the bitten animal may go through one or all of several stages. If the bitten animal is a skunk it may not show any symptoms at all but could become a lifelong carrier. With most animals, however, the virus will spread through the nerves of the bitten animal towards the brain. The virus is relatively slow moving and the average time of incubation from exposure to brain involvement is between 3 to 8 weeks in dogs, 2 to 6 weeks in cats, and 3 to 6 weeks in people. However, incubation periods as long as 6 months in dogs and 12 months in people have been reported. After the virus reaches the brain it then will move to the salivary glands where it can be spread through a bite. After the virus reaches the brain the animal will show one, two, or all of the three different phases.
The first is the prodromal phase and usually lasts for 2-3 days in dogs. Apprehension, nervousness, anxiety, solitude, and a fever may be noted. Friendly animals may become shy or irritable and may snap, whereas, aggressive animals may become affectionate and docile. Most animals will constantly lick the site of the bite. In cats, the prodromal phase lasts for only 1-2 days and they usually develop more fever spikes and erratic behavior than dogs.
From the prodromal phase, animals may enter the furious stage; cats are particularly prone to developing this phase. The furious stage of the disease in dogs usually lasts for 1 to 7 days. Animals become restless and irritable and are hyperresponsive to auditory and visual stimuli. As they become more restless, they begin to roam and become more irritable and vicious. When caged, dogs may bite and attack their enclosures. Animals progress to become disoriented and then have seizures and eventually die.
Paralytic (dumb) phase
Animals may develop the paralytic phase either after the prodromal or furious stage. The paralytic phase usually develops within 2 to 4 days after the first signs are noted. Nerves affecting the head and throat are the first to be involved and animals may begin to salivate as a result of their inability to swallow. Deep labored breathing and a dropped jaw may result as the diaphragm and face muscles become increasingly paralyzed. Animals may make a choking sound and many owners think that there is something lodged in the dog's throat.
The current way to diagnose rabies in animals is to submit the brain for microscopic examination. Some new testing techniques utilizing skin and or blood samples are being studied and used in a few research settings and show promise as a way of testing potentially exposed humans and animals. They are not routinely being used at this time.
There is no treatment. Once the disease develops in humans, death is certain. There have been several reported cases of dogs surviving the infection, but they are very rare.
Vaccination and prevention
Vaccination is the best way to prevent infection and properly vaccinated animals stand very little chance of contracting the disease. While rabies vaccination for dogs is mandatory for all states, it is estimated that up to half of all dogs are not vaccinated. Some communities are also requiring cats to be vaccinated, which is very important because there are currently more cases of cat rabies than dog rabies.
It was estimated that less than ten percent of the cat population is vaccinated thus leading to the high incidence of rabies in cats.
The standard vaccination protocol is to vaccinate cats and dogs at three or four months and then again at one year of age. A year later, a three-year rabies vaccination is recommended. The three-year shot has been tested and shown to be very effective. A few counties, states, or individual veterinarians require yearly or once every two-year vaccination for a variety of reasons that need to be explored more closely.
There is a three-shot series of Human Diploid Cell vaccine that can be used to vaccinate people at high risk. There are some vaccines available for large animals also. The question of vaccinating exotic animals is a common one. There are no approved products for most exotics, however, canine vaccine is used on some species to offer some protection. Vaccinating exotics or wolf hybrids should be dealt with individually in cooperation with your local veterinarian. Keeping a wild animal that is at high risk of being a carrier such as a skunk or raccoon is never recommended.
If an animal bites a human, the animal will be either quarantined or observed for a period of at least ten days to ensure that it does not have rabies. Whether or not the animal was currently vaccinated the community that you live in will dictate the requirements of the quarantine. People that do become exposed to a rabid animal can be given a five-shot post exposure series of Human Rabies Immune Globulin to protect them against being infected.
All warm-blooded animals are at risk for contracting rabies, however, some species are much more resistant than others. Transmission of the virus is almost always through a bite from a rabid animal. There are a variety of different symptoms and once contracted there is no cure, and death is almost always the outcome. The disease is very preventable through vaccination. While relatively rare in humans, the risk of contracting it, and the outcome of the disease make taking precautions with wild animals and vaccination of domestic ones essential.
How Can You Prevent Rabies?
• Have your pets vaccinated against rabies. Any pets which come in contact with wild animals are at risk. Many local health departments conduct public vaccination clinics for dogs and cats. Your veterinarian can also vaccinate your pet against rabies. D uring recent years, confirmed cases of rabies in cats have exceeded the reported cases in dogs in some parts of the United States making vaccination and booster shots critical to your health and that of your pets.
• If your cat or dog has been bitten or attacked by a wild animal or has bites or scratches of unknown origin, call your local health department or animal control officer to report the incident.
• If your cat or dog has bitten a person, call your local health department or animal control officer to report the incident.
• If your cat or dog is sick, seek the advice of your veterinarian.
• Protect your pets from stray or wild animals. Keep your pets from running loose.
• Report stray animals to your local health department so an animal control officer can investigate. Handling stray cats or dogs can be dangerous.
• Do not feed or handle wild animals especially those that appear aggressive or sick. Never keep a wild animal as a pet.
• A wild animal such as a bat, raccoon, fox, skunk, or groundhog which has bitten a person or domestic animal should be sacrificed immediately. Its head (or in the case of a bat, the entire bat) should be submitted to your state or county testing laboratory for examination. Rabies prophylaxis vaccinations may depend on your physician along with laboratory results.
What To Do If Bitten
1. If you are bitten....
....by a wild animals: an animal control officer should sacrifice the animal. All biting wild animals should be tested for rabies as soon as possible.
....By a cat or dog: obtain information about the pet animal. Include a description of the animal and licensing number or identification, owner's name, address and telephone number and the rabies vaccination status whenever available.
2. Immediately cleanse the wound thoroughly with soapy water.
3. Get medical attention. Go to your family doctor or nearest emergency room. DO NOT DELAY CALLING. YOU MAY NEED TREATMENT.
4. Report all bites to your local health department or animal control agency.
REMEMBER, PREVENTION IS YOUR BEST DEFENSE AGAINST RABIES!!!