Do I need tetanus shot after dog bite?

Getting bitten by a dog can be a scary experience. While most dog bites are relatively minor, they do carry a risk of infection, including with the bacteria that causes tetanus. This raises the question – do you need to get a tetanus shot after being bitten by a dog? Here we’ll look at some quick answers to this question, and then dive into more details.

Quick Answers

In most cases, yes, you should get a tetanus booster shot after being bitten by a dog, especially if:

  • The bite broke the skin and caused bleeding or puncture wounds
  • You haven’t had a tetanus shot in the past 5 years
  • You’re unsure of when you had your last tetanus shot
  • The dog bite resulted in a deep or contaminated wound

However, if the bite was minor and didn’t break the skin, and you’re up to date on tetanus vaccinations, a booster shot may not be needed. When in doubt, contact your doctor.

What is Tetanus?

Tetanus is a serious bacterial infection caused by Clostridium tetani. It’s also called lockjaw because one of its classic symptoms is painful tightening of the muscles, usually first felt in the jaw muscles. Tetanus infection occurs through broken skin, usually when wounds become contaminated with dirt, saliva, or feces.

Tetanus bacteria are present worldwide, and can infect all mammals including dogs and humans. The bacteria produce a toxin that travels through the body affecting the nervous system. Without treatment, tetanus can lead to very painful muscle spasms, breathing difficulty, seizures, and even death in up to 10-20% of cases.

Tetanus and Dog Bites

Dog bites pose a risk for tetanus infection because their mouths contain many different bacteria, including sometimes C. tetani. Dog bites almost always break the skin barrier, allowing bacteria to enter tissues they normally wouldn’t infect.

About 20-30% of dog bite wounds become infected. Common infections from dog bites are pasteurella, capnocytophaga, streptococci, staphylococci, and anaerobic bacteria. Though less common, tetanus is a potentially life-threatening risk.

Some dogs may be more likely to carry C. tetani bacteria, especially those that:

  • Spend time outdoors and have access to soil where the bacteria live
  • Have not been vaccinated against tetanus
  • Have puncture wounds or abscesses themselves

However, any dog bite can potentially transmit tetanus, so precautions are important even after minor nips and bites.

Tetanus Vaccine Recommendations for Dog Bites

The tetanus vaccine provides important protection against the potentially deadly tetanus toxin. Because of widespread vaccination, tetanus is now rare in many countries.

Doctors recommend the following for the tetanus vaccine after a dog bite:

  • Clean the wound immediately and thoroughly with soap and water. This removes bacteria and reduces infection risk.
  • Assess when you had your last tetanus shot. Adults should get a tetanus booster every 10 years. More frequent boosters are needed after high-risk wounds.
  • If your last shot was more than 5 years ago, get a tetanus booster within 48 hours of the dog bite.
  • If you haven’t been vaccinated against tetanus or are unsure, also get the shot within 48 hours.
  • Tdap or Td vaccines are options for the tetanus booster. Tdap provides the added benefit of protection against pertussis.
  • If the bite is deep or contaminated, a booster may be recommended even if your vaccine is up to date. Consult your doctor.

Are Tetanus Shots Necessary for Small or Superficial Dog Bites?

For very minor dog bites, especially those that don’t break the skin, tetanus vaccination may not be necessary if you’re up-to-date on boosters. However, it’s still a good idea to discuss small or superficial bites with your doctor.

Factors to consider include:

  • How long ago your last tetanus shot was
  • Whether the bite was a nip or scratch that didn’t draw blood, versus one that broke skin
  • How deep and clean the wound appears
  • If the bite might have introduced saliva or dirt/debris into the wound
  • If the dog is known to spend time outdoors unsupervised and could carry tetanus bacteria
  • If you have any other health conditions that affect immune function or wound healing

For very minor wounds, your doctor may decide the benefits of the vaccine do not outweigh potential risks. But it’s still smart to be cautious and ensure you’re up-to-date on tetanus boosters.

What Are the Risks of Not Getting a Tetanus Shot After a Dog Bite?

Declining recommended tetanus vaccination after a dog bite does put you at increased risk of developing tetanus infection. Possible complications include:

  • Lockjaw – Early sign of tetanus is tightened, painful muscles in the jaw and neck. This can make it very difficult to open the mouth, eat, and swallow.
  • Severe muscle spasms – Tetanus toxin affects nerves that control muscles throughout the body. Muscle spasms can become extremely painful and severe.
  • Breathing problems – Spasms may affect the diaphragm and other muscles involved in breathing, leading to dangerous respiratory distress.
  • Bone fractures – Muscle contractions from tetanus can be strong enough to fracture bones in the spine, limbs, or chest.
  • Heart problems – The stress from tetanus can cause abnormal heart rhythms and high blood pressure.
  • Death – Even with intensive medical care, 10-20% of tetanus cases are fatal. Most deaths are due to respiratory failure.

That said, the overall risk of tetanus infection remains low in places with widespread vaccination programs. But preventing tetanus is much safer than treating this life-threatening illness.

What to Do if You Decline the Tetanus Vaccine After a Dog Bite

If you opt against getting a tetanus booster shot after a dog bite, it’s essential to watch closely for any concerning symptoms, especially:

  • Stiffness or difficulty opening the jaw
  • Tightened muscles or muscle spasms
  • Painful neck and back arching due to muscle contractions
  • Trouble swallowing
  • Fever and general feeling of being unwell

See your doctor immediately if any of these develop, as rapid treatment is needed to control a tetanus infection before it becomes more dangerous. You may need medications to neutralize tetanus toxin, relax muscles, control pain and spasms, and support breathing.

Prevention is still the best approach. Get appropriate wound care, and reconsider the vaccine if you’re exposed again in the future.

Tetanus Precautions After Dog Bites: Summary

Dog bites require care to lower the risk of any infection, including tetanus. Key precautions include:

  • Immediately clean the wound with soap and water.
  • See your doctor for care instructions and to assess tetanus risk.
  • Get a tetanus booster if it’s been over 5 years since your last shot.
  • Watch for signs and symptoms of infection, including tetanus.
  • Return to your doctor if the bite area shows any concerning signs.

Tetanus is a preventable illness thanks to modern vaccination. Follow your doctor’s advice about booster shots, especially after animal bites. With appropriate care, most dog bites heal well and don’t lead to complications like tetanus infection.

Frequently Asked Questions

How long does it take for tetanus to develop after a dog bite?

Tetanus symptoms usually begin appearing 3-21 days after infection. Most cases occur within 14 days. Seeking prompt medical care can help prevent progression of tetanus disease.

Can a small dog bite cause tetanus?

Yes, even small dog breeds can potentially transmit C. tetani bacteria through a bite. The depth and cleanliness of the wound also factor into tetanus risk after a small dog bite.

What are the first signs of tetanus infection?

Early tetanus symptoms often include jaw muscle spasms and stiffness known as lockjaw. Other early signs are muscle tightness in the neck, trouble swallowing, and muscle spasms spreading to other parts of the body.

How long does tetanus vaccine last after a dog bite?

A tetanus booster vaccine provides protection against tetanus for approximately 10 years. More frequent boosters are recommended for people with high-risk wounds or who haven’t been vaccinated.

Can I wait to get a tetanus shot after 48 hours?

It’s best to get the tetanus vaccine within 48 hours of a dog bite for optimal protection. But the vaccine can still be beneficial if given after 48 hours and up to weeks later, and is recommended for unvaccinated individuals after wound care.

Should I get a tetanus shot after a puppy bite?

Even puppy bites can potentially transmit tetanus bacteria. Consult your doctor about whether a tetanus booster is recommended after a puppy bite, especially if the skin was broken.

Is tetanus curable if caught early?

With prompt and intensive medical treatment, tetanus is curable in many cases caught early. But preventing tetanus through proper vaccination and wound care is far preferable and safer.

How many tetanus shots are needed after an injury?

For wound management, a single tetanus booster shot is usually given if it’s been more than 5 years since last vaccination. Additional doses may be recommended down the line to ensure long-term protection.

Can tetanus develop after a small scratch?

Yes, even a minor scratch can introducing tetanus spores into the body. However, the risk is lower than with deeper puncture wounds. Clean minor scratches well and check tetanus vaccine status.


Dog bites can sometimes transmit the bacteria that causes tetanus infection. Seeking prompt medical care, keeping up with the recommended tetanus vaccine schedule, and watching for any concerning symptoms can help minimize the risks from a dog bite. In the vast majority of cases, dog bites resolve without complications like tetanus if given proper initial treatment.

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