Preparation

• Gloves
• Goggles
• Absorbent pad
• Normal saline for irrigation
• 30 ml to 60 ml syringe
• 16 or 18 gauge IV cathlon
• 4×4 gauze

Procedure Steps

Step 1: Health history and physical assessment

Gather information related to the animal and bite/exposure:

• Date and location of exposure
• Type of exposure (bite, scratch, saliva on intact skin, saliva on existing lesion, saliva on mucous membrane, or no known contact)
• Type of attack from the viewpoint of the animal (provoked, unprovoked)
• Wound location
• Animal species
• Animal type (e.g., indoor pet, outdoor pet, wild)
• Health of animal at time of incident and vaccination history
• Symptoms

Assess for risk factors for poor wound healing:

• impaired nutritional status
• advanced age
• medications
• diabetes
• peripheral vascular disease
• autoimmune disease
• immunosuppression
• COPD
• CHF
• anemia
• smoking
• substance use

Consider an x-ray in the following situations: suspected fracture, presence of a foreign body, penetration of bone, joint, tendon, infected puncture wound. Physical assessment:

• inspection for injury to deeper structures (tendon, ligament, bone)
• inspection for presence of a foreign body
• circulation, sensation and movement distal and proximal to the wound
• 2-point discrimination
• sharp/soft discrimination
• pulses
• capillary refill
• range of motion and strength against resistance of all body parts surrounding the wound site
• pain

Step 2: Wash hands, don gloves

All wounds are at risk for infection. Maintain universal precautions throughout procedure.

Step 3: Cleanse the wound with normal saline

Provide pain management as needed to ensure thorough irrigation is achieved.

Note that some antiseptics (i.e., chlorhexidine, iodine) are cytotoxic and damage fibroblasts essential to wound healing. Do not introduce antiseptic solution directly into the wound. The wound itself should be cleansed or debrided with sterile normal saline only. Alternative methods for wound debridement are below.

(a) Irrigation: Use an 18-gauge catheter attached to a 30 mL syringe. 10 PSI of irrigating pressure is needed to dislodge contaminants and bacteria, yet not damage tissue.

(b) Scrubbing: Use a sponge or a brush to remove embedded debris. Avoid soaps or detergents.

(c) Debridement: Remove retained debris and devitalized tissue by surgical excision to improve wound healing time and prevent disfigurement.

Step 4: Leave wound open to heal by secondary intention

The following wounds are at high risk for development of infection and should not be closed with sutures: Tissue adhesives should be avoided in all situations.

• crush injuries
• puncture wounds
• bites involving the hands and feet
• wounds more than 12 hours old
• cat or human bites
• immunocompromised host

Dress the wound as needed to keep clean and dry and to absorb drainage.

Step 5: Consider prophylactic antibiotics

Prophylactic antibiotics should be prescribed if the wound is:

• more than six hours old
• the result of human or cat bites
• a crushing wound
• grossly contaminated
• bone/joint involvement
• patient is immunocompromised

Use the chart below to determine most likely pathogen and to guide antibiotic treatment.

Step 6: Assess tetanus status

A tetanus booster dose is required if the patient has not had a tetanus booster in the last ten years. The combined preparation of tetanus and diphtheria toxoid formulated for adults (Td) is preferred. If the patient has not received pertussis since childhood, then tetanus, diphtheria, pertussis (TdP) should be given. If the wound is excessively dirty, tetanus immune globulin should also be given. See Tetanus immune globulin in the Canadian Immunization Guide (recent edition) for further information.

Step 7: Assess need for anti-rabies therapy and complete notification form

Refer to the Canadian Immunization Guide (recent edition) for management of rabies. All incidents must be reported to the Medical Health Officer. In Saskatchewan, complete the Animal Bite Investigation Form available from www.ehealthsask.ca

Aftercare

• Keep dressing in place for 24 hours.
• Clean wound with soap and water.
• Elevate and apply ice to affected extremity to prevent swelling and reduce pain.
• Monitor for signs of infection: fever, redness, increased pain, swelling, discharge.
• Report incident to Medical Health Officer so observation/examination of animal for rabies can be done as appropriate.
• Inform patient not to shoot animal so assessment of animal can occur.
• Do not pet or feed strange or wild animals.

Patient Education

Follow-up

• Most infections present 48-72 hours after injury so have patient follow-up for wound reassessment within this timeframe.
• Return for reassessment if signs or symptoms of infection are present.

Key Takeaways

• The majority of bites are from animals known to the victim, such as a pet or pet of an acquaintance.
• Providers should maintain a high level of suspicion for rabies when bites are unprovoked (from the point of view of the animal) or when the offending animal cannot be located or quarantined.
• All wounds are at risk for infection, but the organism most likely to cause infection is related to the species of animal that caused the bite.
• Amoxicillin-clavulanate is a good option for empiric therapy of all animal bites.
• Thorough wound assessment and irrigation is the mainstay of treatment for animal bites.
• HIV post exposure prophylaxis is generally not recommended for human bites, given the extremely low risk for transmission.