Assessing The Risk of Rabies From Dog Bites

Important Factors in Determining Exposure and First Aid Procedures

Nov 29, 2009 Mistie Shaw

The pain of a dog bite is extended for a month if rabies vaccinations are required. After a bite, seek medial attention to determine the necessity of rabies shots.

Thanks to the efforts of Louis Pasteur (1822 – 1895), the fear of rabies no longer needs to paralyze people. Building on the work of a colleague, Pasteur created a vaccine that effectively combats the fatal disease. According to the American Centers for Disease Control and Prevention (CDC), animal bites are the most common method of transmitting rabies. However, the possible rabies exposure is a secondary concern in the treatment of a bite. The first step is to provide first aid.

Regardless of the size or severity of a bite, even if it does not appear to have broken the surface of the skin, the area should be washed with soap as soon as possible. Animal studies have shown that immediate and thorough cleansing of a bite wound dramatically reduces the likelihood of rabies. After washing the wound, a health care professional should examine the bite.

The possibility of having been exposed to rabies is considered a medical urgency, not an emergency. That means the course of action regarding treatment needs to be decided quickly, but ambulance lights-and-siren rides are not necessary.

General Information About Rabies

The Rabies virus resides in body tissue and excretions except urine, feces and blood. The spread of rabies most commonly occurs when the saliva of an infected animal enters the bloodstream of another animal via a bite, an open wound or through the mucous membranes of the eyes or mouth.

The rabies virus cannot live very long outside of a body. Environmental conditions determine how long the virus is dangerous, but generally speaking, if virus-infected material is dry, it is not considered to be a threat.

Qualified medical personnel should evaluate any possibility of exposure. There are two types of exposure:

• bite – defined as when skin is penetrated by the teeth. A bite can occur without any noticeable bleeding. Skin has two layers, the epidermis and the dermis. The epidermis can be penetrated and little or no bleeding will occur. However, all bites have the potential to be at risk, even when the wound appears superficial.
• non-bite – Scratches are the most common non-bite wound but transmission of rabies can occur through contamination of a previously injured break in the skin or through the mucous membranes.

Rabies shots given after an animal bite are called post-exposure prophylaxis (PEP).

Dog Bites – After First Aid, What Happens Next?

The answers to several questions will determine what happens next:

• Where did the exposure take place? In any country where rabies vaccinations for animals is widespread, information about the animal is required to make a decision. Rabies in many developing countries is rampant and PEP is mandatory.
• What type of exposure resulted? Rabies exposure is usually transmitted through a bite. When deciding on the necessity of PEP, severity and location of the wound or wounds is not as important as other factors. Any likely contamination by the rabies virus is usually sufficient cause to begin PEP.
• Pertinent information – species, behavior, vaccination, health, current location – about the animal. If the dog is wild or runs loose, is not known to have been vaccinated, attacked unprovoked, appears ill or is unable to be found, PEP is usually required. Any incident involving food is considered to be provoked. Animals who have been given the rabies vaccine are unlikely to have acquired rabies.

Once PEP has been started, it should not be discontinued for localized or minor drug reactions. The series may be stopped if testing of the animal shows that it was not rabid.

Rabies Treatment: Getting the Rabies Shot Series

In humans, rabies incubation may take up to a year. Normally, PEP should be started within 24 hours after the possible exposure; however, it may be started any time before rabies symptoms actually appear. Patients who were not vaccinated prior to the exposure are usually given both the human rabies immune globulin (HRIG) and the rabies vaccine on the first day. It is a painful experience.

The vaccine is administered in a series with the number of rabies shots dependent on the type of vaccine and the manufacturing location. Usually there are five injections given according to the following schedule:

• day 0, the first rabies shot,
• day 3,
• day 7,
• day 14, and
• day 28.

Possible Rabies Exposure in Developing Countries – Differences in Medical Response

According to the CDC website, the HRIG and first rabies vaccine shot should never be given in the place on the body or in the same injection, but this does not seem to be a practice always adhered to in developing countries. Anecdotal information on the Internet states that doctors in Mexico, South America and China recommend abstaining from exercise, caffeine and alcohol during the entire month of rabies treatment.

The best way to avoid the necessity of going through the trauma of getting rabies shots is to avoid animals that may carry rabies. Do not pet or feed stray dogs. Contracting rabies in developing countries is still a major risk, so avoid interaction with unknown animals. Remember the Benjamin Franklin's sage advice, “an ounce of prevention is worth a pound of cure.”

This article does not take the place of medical treatment. For any animal bite, seek advice from a qualified medical professional. Contact the CDC via e-mail at cdcinfo@cdc.gov.

Source:

American Centers for Disease Control and Prevention

The copyright of the article Assessing The Risk of Rabies From Dog Bites in General Medicine is owned by Mistie Shaw. Permission to republish Assessing The Risk of Rabies From Dog Bites in print or online must be granted by the author in writing.

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Dec 1, 2009 6:24 AM

Guest :

First aid for dogs, just like first aid for humans, is an effective combination of knowledge, supplies and skills, put into action for the benefit of your four-legged friend.

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