Page 281 - Cote clinical veterinary advisor dogs and cats 4th

120.e2 Bite Wounds

Bite Wounds
VetBooks.ir Differential Diagnosis

(i.e., mauling with gaping wounds, large
BASIC INFORMATION
subcutaneous pockets, and missing tissues) • Other penetrating wounds: punctures from
Definition ○ Wounds may penetrate into the abdomen sticks, metallic objects, projectiles (e.g.,
Wounds caused by the bite of another animal. or thorax bullets, pellets, arrows)
Injury is caused by a combination of penetrat- ○ Look for counter-bites, punctures/injuries • Vehicular trauma
ing, shearing, crushing, and avulsion forces. from occlusion of the maxillary and • Other crushing injuries
mandibular canine teeth.
Synonyms ○ Cellulitis, necrosis, or infection possible Initial Database
• Big dog–little dog (BDLD) with older wounds • Complete physical examination
• Mauling • Subcutaneous emphysema with airway injury ○ Locate all wounds; look for counter-bites;
• Animal attack • Lameness from localized swelling or fractures not all wounds will have completely
• Hemorrhage (severe if major vessel severed) penetrated the skin
Epidemiology • Evidence of shock: tachycardia (bradycardia • Orthopedic/neurologic examination as
SPECIES, AGE, SEX in cats), pale mucous membranes, weak and indicated (pp. 1136 and 1137)
• Dogs and cats of any age thready pulses, weakness, collapse • If severely injured: CBC, serum chemistry,
• Any sex, may be more likely with intact • Fever, lethargy, depression, inappetence if urinalysis
animals that roam wounds are infected • Severe injuries, severe infection, or patients
in shock: electrolyte panel, blood gas
RISK FACTORS Etiology and Pathophysiology analysis, blood pressure, electrocardiogram
• Roaming outside: fights with other dogs/ • The canine teeth grab and puncture the skin (ECG)
cats and wild animals and underlying tissues. • Cats: FeLV/FIV testing
• Dogs with territorial, food, or fear aggression • Closed jaws crush tissues within the bite. • Blood typing/cross-matching if severe
• Multiple-animal household • Skin is separated from underlying muscles, hemorrhage
• Meeting unfamiliar animals or tissues are avulsed as aggressor pulls away • Diagnostic imaging
and/or shakes head. ○ Radiographs (orthogonal views) of affected
CONTAGION AND ZOONOSIS • Bacterial contamination of the wounds from areas, especially if abdominal or thoracic
• Rabies: zoonotic (p. 861) the oropharyngeal cavity, surrounding hair penetration is suspected or lameness is
• Feline immunodeficiency virus (FIV) and and skin, and the environment present
feline leukemia virus (FeLV): transmitted cat ○ Results in localized abscesses, regional
to cat by fighting behavior (pp. 325 and cellulitis, and/or sepsis Advanced or Confirmatory Testing
329) • Tissue damage may compromise vasculature, • Diagnostic imaging
• Babesia gibsoni: endemic in pit bull dogs causing progressive tissue ischemia and ○ Abdominal ultrasound if penetrating
(p. 105) necrosis. The full extent of tissue loss may wounds (p. 1102)
not be evident for up to 5 days. ○ CT or MRI for severe head injuries once
ASSOCIATED DISORDERS ○ Toxins, free radicals, cytokines released stabilized
• Tissue necrosis from dying tissues can cause shock • Culture wounds (aerobic and anaerobic) after
• Cellulitis +/− death. they have been cleaned, flushed, and debrided
• Sepsis • Bites penetrating the abdominal or thoracic
• Penetration of internal organs (e.g., intestines, cavities may also damage internal organs. TREATMENT
spleen, kidneys, liver, urinary tract, lungs) ○ High risk of septic abdomen from bowel
• Septic abdomen penetration Treatment Overview
• Pyothorax • Ongoing fluid losses from severe wounds lead Stabilize critical patient first. Under general
• Fractures/osteomyelitis to hypoproteinemia and hypoalbuminemia. anesthesia, wounds should be clipped, cleaned,
explored, and debrided/treated using sterile
Clinical Presentation technique and instruments. Some wounds may
HISTORY, CHIEF COMPLAINT DIAGNOSIS be closed primarily with or without a drain.
• History of a fight with or attack by another Diagnostic Overview Open wound management is often necessary.
animal Diagnosis is typically evident based on history of Penetrating injury into the abdomen necessitates
• Acute presentation: swelling in the area of a recent animal fight or attack and the presence emergency celiotomy. The need for thoracotomy
the injury(ies), pain, open wounds, bleeding, of wounds on physical examination. Often, for penetrating wounds of the thoracic wall
crusted/matted fur, lameness, collapse visible wounds represent the tip of the iceberg, depends on the type and severity of wound.
• Chronic presentation: above complaints plus with more extensive tissue damage in deeper
purulent discharge, lethargy, depression if tissues. Complete physical +/− orthopedic Acute General Treatment
wounds are infected examination, minimal database should be Single bites:
completed. Diagnostic imaging (radiographs, • Assess and treat wounds under general
PHYSICAL EXAM FINDINGS ultrasound) is performed to assess for ortho- anesthesia using sterile technique.
• Pain and swelling pedic injury and evidence of penetration into • Clip hair generously around wounds; protect
• Open wounds, punctures, or bruising on the abdominal or thoracic cavity. Advanced wounds with sterile lubricating gel.
the skin: clip hair to find wounds imaging (CT, MRI) may be indicated for • Scrub skin with chlorhexidine or Betadine
○ Most common locations: limbs, head/ severe head wounds to assess for fractures and scrub (avoid chlorhexidine near the eyes).
neck, thorax/abdomen, perineum nervous system involvement. Wounds should ○ Do not scrub open wounds.
○ Severity varies from simple punctures to be explored under general anesthesia after the • Evaluate pocket size and wound depth with
lacerations to severe avulsion/degloving patient has been stabilized. a sterile hemostat.

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