Getting bitten by a dog can be a scary experience, especially if the dog’s rabies vaccination status is unknown. Rabies is a deadly virus that is spread through the saliva of infected animals. If rabies is left untreated in humans, it is almost always fatal. Luckily, rabies is preventable if treated right after exposure before symptoms start.
What is rabies?
Rabies is a viral disease that affects the central nervous system of mammals, including dogs, cats, bats, raccoons, skunks, and foxes. It is spread through infected saliva, usually through bites. Rabies causes inflammation of the brain and spinal cord, leading to symptoms like aggression, excessive salivation, paralysis, and hallucinations. Eventually, it leads to death if left untreated.
Rabies affects over 59,000 people worldwide each year, causing tens of thousands of deaths. In the U.S., rabies in humans is rare thanks to widespread vaccination of domestic animals and availability of post-exposure treatment. Only 1-3 cases of human rabies are reported each year in the U.S.
The rabies virus has an incubation period that can last anywhere from 1-3 months before symptoms start. This means a bite from a rabid animal may not show symptoms right away. But once they do start, rabies is almost always fatal within a few days, as there is no cure once clinical signs appear.
What are the chances a dog bite will transmit rabies?
The likelihood of getting rabies from a dog bite depends on several factors:
- Vaccination status of the dog – Unvaccinated dogs are more likely to have rabies.
- Location of the bite – Rabies is more common in some parts of the world.
- Health status of the dog – Dogs showing clinical signs of rabies are more likely to transmit it.
- Type of exposure – Bites are more dangerous than scratches.
- Site of the bite – Bites to the head, neck, and hands have shorter incubation periods.
Estimates suggest:
- Less than 50% of dog bite cases involve dogs vaccinated for rabies.
- Around 15% of reported rabid animal cases in the U.S. occur in dogs.
- Less than 1% of dog bites require rabies post-exposure treatment.
Even though the chances of getting rabies from a dog bite are low overall, especially in countries like the U.S., getting treated is still crucial if the dog’s rabies status is unknown.
What should you do if bitten by a dog?
If you are bitten by a dog, here are some steps you should take:
- Wash the wound – Thoroughly rinse the wound with lots of soap and water to reduce the risk of infection. This can also help remove any rabies virus that may be present.
- Get medical attention – See a doctor to determine if you need antibiotics, stitches, or a tetanus shot.
- Talk to the owner – Try to find out if the dog is up-to-date on rabies vaccinations. Get contact details for follow up.
- Report the bite – Notify animal control officials, especially if the dog’s vaccine status is unknown or if the dog was acting strangely.
- Get post-exposure treatment – If the dog is unvaccinated, of unknown status, or showing signs of rabies, immediately start rabies post-exposure treatment.
Taking these steps right after a dog bite can help prevent rabies infection and other health complications.
What is rabies post-exposure treatment?
Rabies post-exposure treatment consists of:
- Wound cleansing – Thoroughly washing the bite site with soap and water, and a virucidal agent like povidone-iodine.
- Vaccination – A series of 4 rabies vaccine shots over 14 days. The first dose should be given as soon as possible after exposure.
- Rabies immune globulin (RIG) – A single injection of antibodies against the rabies virus, given at the same time as the first vaccine dose.
This combination is extremely effective at preventing the rabies virus from infecting the body if given properly within the recommended timeframe. RIG provides immediate short-term immunity, while the vaccines stimulate the body’s production of antibodies against rabies.
The treatment may be adjusted if the person has been previously vaccinated against rabies. But it’s still crucial to get medical assessment after any potential rabies exposure.
What are the timeframes for rabies treatment?
For rabies post-exposure treatment to be effective, it must be started as soon as possible after a bite occurs:
- Immediately – The wound should be washed thoroughly with soap and water for at least 15 minutes as soon as it occurs.
- Within 24 hours – The first dose of rabies vaccine should be given.
- Within 72 hours – Rabies immune globulin (RIG) should be given for maximum effectiveness.
- Within 7 days – The full course of 4 vaccine doses should be started.
These timeframes are critical. If treatment is delayed beyond the recommended windows, the risk of developing rabies increases substantially.
Rabies Post-Exposure Prophylaxis Timeline
| Time after exposure | Treatment guidelines |
|---|---|
| Immediately | Clean wound thoroughly with soap and water |
| Within 24 hours | Administer first dose of rabies vaccine |
| Within 72 hours | Infiltrate rabies immune globulin (RIG) around the wound |
| Within 7 days | Begin full 4-dose vaccine series over 14 days |
Sticking to these recommended timelines is the best way to prevent rabies virus from infecting the central nervous system before an immune response can take effect.
What are the side effects of rabies vaccine and RIG?
The rabies vaccines and RIG used today are extremely safe. Most side effects, if they occur, tend to be minor and temporary.
Common vaccine side effects:
- Soreness, redness, swelling at injection site
- Headache
- Fever
- Nausea
- Muscle aches
These usually resolve within a few days on their own.
RIG side effects:
- Pain or tenderness at injection site
- Localized skin reactions
- Low-grade fever and headaches
Severe allergic reactions are possible but very rare with current vaccines and RIG products. Symptoms like facial swelling, hives, and difficulty breathing should be immediately reported to a doctor.
What happens after getting rabies treatment?
After receiving the full post-exposure rabies treatment regimen:
- Most people develop immunity against rabies virus within 7-10 days.
- No further vaccine doses are required, even if exposed again.
- Blood tests can confirm adequate rabies antibody levels around 2-4 weeks after vaccination.
- The CDC recommends getting another 2-dose vaccine series if exposed again after more than 2 years.
It’s very reassuring that rabies treatment is extremely effective when administered promptly after a bite from a potentially rabid animal. And immune memory persists for at least a couple years after completing the vaccine series.
What if I’m bitten by a vaccinated dog?
If a dog is up-to-date on rabies vaccinations, the risk of rabies transmission from a bite is very low. However, it’s still wise to take some precautions:
- Wash the wound thoroughly with soap and water.
- Get medical care to assess if antibiotics or stitches are needed.
- Notify animal control and have the dog quarantined for 10 days to watch for any signs of rabies.
- Consult a doctor about whether post-exposure treatment is recommended based on wound severity.
Since no vaccine is 100% effective, a small risk of rabies can’t be completely ruled out even from vaccinated pets. Speaking with a doctor can provide more clarity if post-exposure treatment is needed after a bite from a vaccinated animal.
What are the first symptoms of rabies in humans?
The early symptoms of rabies can be nonspecific and flu-like. They typically start 2 to 12 weeks after a bite or exposure. Early signs can include:
- Fever
- Chills
- General weakness
- Headache
- Nausea
- Vomiting
- Loss of appetite
- Fatigue
As the infection progresses, more specific neurologic symptoms arise:
- Irritability
- Anxiety
- Confusion
- Agitation
- Hyperactivity
- Difficulty swallowing
- Hydrophobia (fear of water)
- Insomnia
- Partial paralysis
Once clinical signs of rabies appear, it is nearly 100% fatal. That’s why early post-exposure treatment is so critical after suspect bites before any symptoms emerge.
What happens in the final stages of human rabies?
If rabies is not treated before symptoms arise, the disease progresses to the final fatal stage within 3-7 days after initial neurologic signs appear. This stage consists of:
- Fever spikes – Body temperature soars as high as 107°F (41.7°C).
- Hallucinations – People may see, hear or sense things that aren’t real.
- Agitation and bizarre behavior – People may feel very anxious, fearful, agitated or exhibit erratic behavior.
- Partial paralysis – Jerking muscles and convulsions occur, with partial paralysis setting in.
- Difficulty swallowing – Spasms in the throat make swallowing painful and difficult.
- Excess saliva – Uncontrolled drooling occurs due to an inability to swallow.
- Hydrophobia – Painful spasms occur if fluids are consumed, making people fear water.
- Cardiac and respiratory arrest – The brainstem becomes inflamed leading to critical organ failure.
Death usually occurs within 3 to 4 days after these severe neurologic signs appear. Rabies ultimately causes death by impairing critical brainstem functions like breathing, heart rate, and blood pressure control.
How is rabies diagnosed in humans?
Several tests are used to diagnose rabies in humans:
- Viral antibody tests – Blood, skin, corneal and saliva samples are tested for rabies virus antibodies.
- Skin biopsy – Examining skin samples under the microscope for presence of rabies virus.
- PCR tests – Detecting viral genetic material from saliva, skin or CSF samples.
- Viral culture – Isolating the live rabies virus from saliva, urine, or brain tissue.
These tests can confirm rabies, especially in the later stages when antibodies and viral load are high. However, no test can rule out rabies infection during the early incubation period. That’s why post-exposure treatment is initiated based on exposure risk rather than diagnostic testing.
Key Points
- Rabies is highly fatal if treatment is delayed until after symptoms start.
- Seek immediate medical care for risk assessment and treatment after any potential rabies exposure.
- Post-exposure treatment with rabies vaccine and immunoglobulins prevents the disease if given in time.
- Rabies treatment has minimal side effects and provides long-lasting immunity.
- Rabies remains rare in humans due to animal control and post-exposure prophylaxis.
Conclusion
Rabies is a serious but preventable viral disease that can spread to humans through the bite of an infected animal. If a dog’s rabies vaccination status is unknown, immediate medical assessment is crucial after a bite to determine if post-exposure treatment is warranted. Timely administration of rabies vaccine and immunoglobulins has proven extremely effective in preventing the disease. But prompt action is key, as rabies is almost always fatal once clinical symptoms start. Thankfully with proper treatment, rabies infection and its potentially terrifying health consequences can be avoided.