Animal Bites

Many different types of animals ranging from dogs and cats to hamsters, raccoons, ferrets, and squirrels can bite adults and children. Many times, bites are from the family pet.

Animal bites usually are either provoked or unprovoked. A provoked bite would occur if you tease a dog or try to take away the dog’s food while the dog is eating. An unprovoked bite may occur if you are sitting in your backyard and a raccoon runs out of the woods and attacks you for no known reason.

Although most bites need to be checked by a doctor, if you do not seek immediate attention after the bite has occurred, then watch closely for signs and symptoms of infection. These symptoms may signal there is infection or debris still in the wound (such as teeth, clothes, or dirt):

• Redness at or around the bite site
  
  
• Swelling
  
  
• Pus (thick) drainage from the wound
  
  
• Increasing pain
  
  
• Localized warmth at the bite site
  
  
• Red streaks leading away from the bite site
  
  
• Fever

Most animal bites should be evaluated in a doctor’s office, at a walk-in clinic, or in a hospital’s Emergency Department for these reasons:

• The risk of infection
  
  
• Broken or embedded teeth (cats) or other foreign material in the wound
  
  
• Underlying nerve and blood vessel damage

These types of bites pose the highest risk of infection and therefore require prompt evaluation:

• Dog bites - Because of the crushing mechanism of the bite
  
  
• Cat bites - Because of the puncture mechanism of the bite
  
  
• Wild animal bites (from raccoons and squirrels, for example) and dog or cat bites (your pets may have themselves been bitten by stray animals) - Because of the risk of contracting rabies

Certain bite wounds require immediate attention:

• Bite caused by a wild animal or a stray dog or cat
  
  
• Possibility of teeth, dirt, or other matter in the wound
  
  
• Excessive bleeding
  
  
• Weakness or numbness of the area or another area away from the bite
  
  
• Any other symptoms or concern that you may have regarding a bite wound

The doctor will assess the risk of infection, look for other injuries, and try to minimize any scarring or deformity from an animal bite.

Inspection: The wound will be thoroughly examined to look for any debris such as dirt, grass, teeth, clothing, or other objects that may have become embedded into the bite area. Sometimes the wound will be numbed with lidocaine so it will not hurt while the doctor makes a complete inspection of the area. This is not always necessary and depends on the extent of the injury.

X-rays: The doctor may order x-rays to look for fractures of bones or to make sure nothing remains in the wound. Although certain objects such as metal always show up on x-ray, some objects such as dirt and grass do not always appear. That’s why careful inspection and washing out the wound are key to proper care. Despite best efforts, there is always a risk that foreign material will be missed and may be in the wound.

Irrigation: This is very important to preventing infection. Several techniques are used but the idea is the same. The doctor will spray irrigation solution (usually saline solution) into the wound with either an irrigation device or a syringe (without the needle) in order to wash out anything that may contaminate the wound. Despite best efforts and intentions, infections can and still do occur in animal bites.

Debridement (tissue removal): Dog bites are noted for being crush type injuries. This will macerate and tear apart the skin and tissue in humans. The result is that skin tears often are not repairable because of the amount of damage or the significant crushing mechanism. These areas usually have either no blood supply to them or decreased blood supply and will not survive and are considered to be dead tissue.

• In some cases, it may be necessary for the doctor to remove or debride the skin. This involves numbing the wound with lidocaine and then cutting the skin with either small scissors or a scalpel to remove the tissue.
  
  
• This not only will reduce the risk of infection but also will promote quicker healing and may even allow the doctor to obtain better wound closure.

Closure: Not all animal bites need to be closed with stitches. Some wounds are sutured (stitched) immediately after they occur (this is referred to as primary closure). Some are repaired a few days later (referred to as delayed closure). Some animal bites are never sutured.

• Relatively clean wounds or those that can be easily cleansed may be stitched immediately. Also bites to cosmetic areas (such as the face) are usually sutured immediately.
  
  
• Delayed closure or no closure at all will most likely occur in any wound that is on an arm or leg because of decreased blood flow and increased risk of infection. Also, delayed closure is more likely if the wound is heavily contaminated (dirty) or has a significant amount of tissue damage or crushed tissue. It is important to note that animal bites to the hand have a very high risk of infection so they are generally not sutured immediately. Bite wounds to hands are excellent candidates for delayed closure.

The treatment of animal bites, after initial inspection, irrigation, debridement, and possibly closure depends on the doctor's experience, preference, and the type of wound and location of the wound.

|Self-Care at Home|

Thoroughly clean the wound by washing with soap and tap water as soon as possible. A light scrubbing should occur during the wash. Then put a clean and dry bandage over the area. This treatment should not replace proper evaluation by a doctor.

|Medical Treatment|

Depending on the status of the bite wound, local wound care varies.

If the wound was sutured on the first visit, then the wound should be kept clean and dry. Showers are permitted, but the area should be dried by patting it softly to avoid disrupting the sutures.

If the wound was left open, then the doctor may recommend daily soaks or other treatments.

|Medications|

If antibiotics are prescribed, it is important to recognize that they are not used to treat an infection. They are used to try to prevent infection.

• Bites that generally warrant antibiotics are these:
  
  
  • Cat bites with a deep puncture
    
    
  • A wound that required tissue removal (debridement)
    
    
  • A heavily contaminated wound
    
    
  • Bites in elderly
    
    
  • Bites in people with underlying chronic medical conditions (such as diabetes)
  
  
• Those bites to areas with good blood supply (the face) generally do not require antibiotics.
  
  
• The most common antibiotics prescribed are amoxicillin/clavulanate (Augmentin) or a combination of 2 medications, amoxicillin and cephalexin (Keflex). Other antibiotics used include erythromycin, co-trimoxazole (Bactrim), and azithromycin (Zithromax).
  
  
• If used in the initial period, a 5-day course of antibiotics is generally adequate, although some recommend only 3 days and some 7 days. These rules change if you are actively treating an infection, or if the bite was particularly dirty or contaminated.

Most bite wounds are treated with over-the-counter pain medications such as acetaminophen (Tylenol) or ibuprofen (Motrin). Occasionally, the doctor may prescribe a stronger pain medication for the short-term control of pain from the bite.

When you are discharged from the Emergency Department or leave your doctor’s office, you should receive instructions on how to care for your bite wound.

|Follow-up|

Most doctors will recommend a reevaluation of bites in 48 hours to look for infection.

If the wound was sutured (you received stitches), the doctor will tell you when the stitches will need to be removed.

• Typically stitches in the face are removed in 3-5 days.
  
  
• Stitches over major joints stay in 10-14 days.
  
  
• Stitches in other areas are removed in 7-10 days.

|Prevention|

With common sense, you can lower your risk of being bitten by an animal:

• Avoid contact and interaction with unknown animals. Even animals that appear friendly can bite if provoked.
  
  
• Do not feed or try to catch or play with wild animals such as squirrels, raccoons, or rats.
  
  
• Do not disturb an animal while it is feeding or taking care of its young.
  
  
• Use great care when "aggressively" playing with an animal. Even the family dog can bite its owner by accident while playing tug of war over that old shoe.
  
  
• Do not stick your fingers into animals' cages—for example, at the pet store, zoo, or dog show.

|Outlook|

The majority of animal bites heal quickly without serious complications.

Media file 1: Bites, animal. A crush and tear type injury that occurs from a dog bite.

Media type:  Photo

Media file 2: Bites, animal. Same injury (dog bite to the finger) from a different angle.

Media type:  Photo

dog bite, cat bite, squirrel bite, raccoon bite, wild animal bite, hamster bite, ferret bite, animal bites

Author: Scott D Fell, DO, FAAEM, Medical Director, Emergency Care Center, Bon Secours Venice Hospital.

Coauthor(s): Christina L Kukula, DO, Consulting Staff, Walk-in-Care Center, Bon Secours Venice Hospital.

Editors: Scott H Plantz, MD, FAAEM, Research Director, Assistant Professor, Department of Emergency Medicine, Mount Sinai School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Anthony Anker, MD, FAAEM, Attending Physician, Emergency Department, Mary Washington Hospital, Fredericksburg, VA.