Dog Bite – What You Should Know

Ever been bitten by a dog? Dog bite account for up to 90% of all animal bites. 4.5 million dog bites occur each year in the U.S., and more than 27,000 victims require reconstructive surgery.

A large percentage of dog bite victims are children. About 10 to 20 people in the US, mostly children, die from dog bites each year. However, most bites cause relatively minor wounds.

Although some breeds of dogs have been identified as being more aggressive than other breeds, any dog may attack when threatened.

Dog breed and aggression

Aggressive dogs (higher attack rate)

• Bull Terrier.
• Cocker Spaniel.
• Great Dane.
• Chow Chow.
• Pitbull.
• Collie.
• Rottweiler.
• Doberman Pinscher.
• Siberian Husky.

Less aggressive dogs (“family dogs”)

• Boxer.
• Golden Retriever.
• Dalmatian.
• Irish Setter.
• English Setter.
• Labrador Retriever.
• English Springer.
• Spaniel.

Almost one-half of all reported cases of dog bites involve an animal owned by the victim’s family or the victim’s neighbours. Most victims are involved in normal, non-provoking activities before the dog attacks^. For example, neonatal deaths resulting from a dog bite most often involve a sleeping baby.

Pitbull breeds accounted for more than 41 per cent of dog bite-related fatalities, three times as many as German shepherds. The risk of being bitten by a dog increases if there is a dog in the home; the more dogs there are, the greater the risk.

Men are more frequently bitten by dogs than women, who are bitten by cats more often. Children between the ages of 5 and 9 are more likely to be bitten by a dog than other age groups. Children are also more likely to need medical attention.

What should you do if a dog bites you?

 If bitten by a dog or someone that you are with, you need to do the following:

1. Go to a safe place away from the dog that has bitten you to prevent further attack and injury. 
2. Assess the underlying structures that may have also been injured in the attack.
3. Clean the dog bite with tap water.
4. Gather information about the dog.

• • If the dog’s owner is nearby. 
  • Ask for the dog’s vaccination history. 
  • Get the owner’s name, telephone number, and veterinarian’s contact information, if possible, also ask to see some sort of ID (except if you are the owner).
  • If the dog is unaccompanied, ask anyone who witnessed the attack if they’re familiar with the dog and know where the owner lives.

5. The dog should be observed for the following behaviours viz:

• • Withdrawal from people and other animals.
  • Restless/irritable and attacking inanimate objects and people.
  • Hypersensitivity to light, sounds, and touches.
  • Fever.
  • Change in tone or bark.
  • A change in personality and behaviour by becoming agitated, anxious, and fearful. Friendly dogs may become aggressive and vice versa. Signs present themselves within the first 2-3 days.
  • Disorientation /seizures.
  • Foaming from the mouth. 
  • Other symptoms are laboured breathing, choking, weakness, respiratory failure, and ultimately, death.

Hospital evaluation for dog bite

A timely presentation is considered an extremely important factor and the following should be done.

• • Obtain the history of the bite event, including home treatment of wounds, body parts involved, and other symptoms. 
  • The offending animal should be accurately identified. This helps guide medical and surgical algorithms, as well as specific antimicrobial therapy. 
  • Is the dog available to be observed?
  • Was the bite provoked or defensive rather than an unprovoked attack?
  • Where is the bite located?
  • What is the past medical history of the victim?
  • The victim’s tetanus status needs to be known.
  • The extent of the wound is evaluated. The doctor examines the injury to see whether the bite was deep enough to damage muscles, tendons, nerves, or bones. 
  • Diagrams and photographs are useful, especially in cases that may involve litigation.

Investigations

• Baseline radiographs may be obtained, especially with puncture wounds near a joint or bone

Treatment for dog bite

1. Wound management

Intact skin is washed with soap and water while open wounds need to be irrigated with normal saline. A local anaesthetic should be used as needed.

A meta-analysis found that copious irrigation significantly reduced the infection rate by more than 50%. Foreign debris needs to be completely removed from the wound to prevent complications.

2. Surgical debridement & closure

Not all wounds require surgical debridement. Only devitalized and necrotic tissue should be debrided. Many wounds should not be closed. Wound closure is done only for select wounds (i.e., that have minimal damage and can be cleansed effectively). Those older than 24 hours with signs of infection are best left to heal by secondary intention.

3. Antibiotic treatment

Most infected dog bite wounds yield polymicrobial organisms, therefore, treatment with prophylactic antibiotics for three to seven days is appropriate for dog bite wounds, unless the risk of infection is low or the wound is superficial. If frank cellulitis is evident, a 10- to 14-day course of treatment is more appropriate. Amoxicillin-clavulanate potassium (Augmentin) is the antibiotic of choice for a dog bite.

 For patients who are allergic to penicillin, doxycycline (Vibramycin) is an acceptable alternative, except for children younger than eight years and pregnant women.

4. Assessing the risk of rabies

Patients with a bite from a non-provoked dog should be considered at higher risk for rabies infection than patients with a bite from a provoked dog. If the dog owner is reliable and can confirm that the animal’s vaccination against the rabies virus is current, the dog may be observed at the owner’s home for a least 10 days. 

Observation by a veterinarian is appropriate when the vaccination status of the animal is unknown. If the animal cannot be quarantined for 10 days, the dog bite victim should receive rabies immunization.

Rabies immunization should begin within 48 hours after the bite, but it can be subsequently discontinued if the animal is shown to be free of the rabies virus.

Rabies immunization consists of an active immune response with a vaccine and a passive immune response with rabies immune globulin (RIG).

• Not previously vaccinated.

1. 1. RIG. Administer 20 IU per kg body weight. If anatomically feasible, the full dose should be infiltrated around the wound(s) and any remaining volume should be administered IM at an anatomic site distant from vaccine administration.
   2. Vaccine. 1 mL, IM (deltoid area), once daily on days 0, 3, 7, 14 and 28.

• Previously vaccinated

1. 1. RIG. Not to be given.
   2. Vaccine. 1 mL, IM (deltoid area), once daily on days 0 and 3.

Three commonly used rabies vaccines are diploid cell vaccine (HDCV), rabies vaccine adsorbed (RVA) and purified chick embryo cell vaccine (PCEC). All are formulated for intramuscular use, but HDCV is also available for intradermal use.

5. Tetanus Prophylaxis (if the history of tetanus toxoid is unknown or less than 3 years)

• Minor, clean wound

Tetanus and diphtheria toxoids adsorbed (Td) are given.

• Contaminated wounds 

 Tetanus and diphtheria toxoids adsorbed (Td) are given with Tetanus immunoglobulin (TIG).

For children younger than seven years, DTP (dT, if pertussis vaccine is contraindicated) is preferred to tetanus toxoid alone. For persons seven years or older, Td is preferred to tetanus toxoid alone. Diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) may be used instead of DTP for the fourth and fifth doses.

Medical conditions associated with a high risk of infection after a dog bite

• Chronic disease.

• Diabetes mellitus.

• Immunosuppression.

• Liver dysfunction.

• Previous mastectomy.

• Prosthetic valve or joint.

• Splenectomy.

• Systemic lupus erythematosus.

How to prevent dog bites

• When choosing a dog for a family pet, pick one with a good temperament.
• Stay away from any dogs you don’t know.
• Never leave young children alone with a dog, especially an unfamiliar one.
• Don’t try to play with any dog that is eating or feeding its puppies.
• Whenever you approach a dog, do so slowly, and give the dog the chance to approach you.
• If a dog becomes aggressive, do not run away or scream. Stay calm, move slowly, and don’t make eye contact with the dog.

Complications of dog bite

Certain infections from dog bites can be very serious and lead to complications. Without treatment, these infections can be fatal viz:

1. Capnocytophaga

Many kinds of bacteria called capnocytophaga live in the mouth of dogs. If one has capnocytophaga infection from a dog bite, the following symptoms may be present:

• • Blistering around the wound.
  • Redness, swelling, and pain around the wound.
  • Oozing from the wound.
  • Fever.
  • Vomiting and diarrhoea. 
  • Headaches.
  • Joint pain.

2. Sepsis

Untreated animal bites can sometimes lead to sepsis. Sepsis is a severe reaction to infection, and it can be life-threatening. The signs include:

• • High or low body temperature.
  • Confusion.
  • Extreme daytime sleepiness.
  • Severe pain or discomfort.

seek immediate medical attention immediately if sepsis is suspected. 

3. Rabies

One can get rabies following a dog bite. The first symptoms of rabies are:

• • Headache, fever, and other flu-like symptoms.
  • Weakness.
  • Itching or prickling feeling around the bite.
  • Rabies is fatal if a person does not receive treatment. People should see their doctor straight away if they think that the dog that bit them might have rabies. Post-exposure rabies vaccination can treat the infection.

4. Tetanus

A dog bite can cause tetanus. Symptoms of tetanus include:

• • Cramping in the jaw.
  • Muscle spasms, usually in the stomach.
  • Difficulty swallowing.
  • Muscle stiffness.

Tetanus is a serious infection. People with any of these symptoms need immediate medical attention. Medications, such as antibiotics, as well as a tetanus vaccine. Read more about tetanus.

Conclusion

In Dog bites, obtaining the history of the bite event is of major importance and a timely presentation to the hospital is considered an extremely important factor. Exposure to a rabid animal does not always result in rabies.

If a dog bites treatment protocol is initiated promptly following a rabies exposure. If rabies exposure is not treated and a person develops clinical signs of rabies, the disease usually results in death.