Treating animal bites Around 64% of Australian households
have a pet. Many Australians report an animal bite at least once in their
lifetime.
Around 100,000 Australians are bitten by dogs each year, 13,000 of those injured
needing medical treatment 85 - 90% of animal bites are dog bites.
Children under the age of 5 are at the greatest risk of a bite usually on the
face. Adults tend to be bitten on the upper arm by freely roaming dogs. Around
18% of dog bites become infected.
Only 10% of animal bites are cat bites which are often unprovoked. 28-80%
of the wounds become infected.
Cat scratch fever can be transmitted by the bite of an infected cat or cat flea.
Human bites account for 2-3% of all bites,
with males between 16 and 25 being at greatest risk of being bitten. Infected
human bites may contain bacteria such as Streptococcus or Staphylococcus aureus.
Any human bite should be treated seriously, especially if it is bleeding
even slightly. 2 to 3% of animal bites are caused by rodents, 10% of which
become infected. Rat bite fever is a type of rodent infection which is
characterised by a triad of fever, rash and arthritis. In Australia, people who
handle bats are at risk of Australian bat lyssavirus infection. the ABL virus
is related to rabies and carried by bats but is not spread to native or
domesticated animals, although it rarely infects humans. There have been 3
fatal cases of ABL infection in Australia in the mid-1990s and 2013. The
management of animal bites Document fang penetration,
X-ray the bite, treat infected wounds,
administer tetanus booster. Patient Education Document fang penetration
Animal fangs can inoculate bacteria into deep tissues like bones,
vessels, tendons, muscle and nerves. Dog bites cause crushing wounds because of
their rounded teeth and strong jaws. The sharp pointed teeth of cats cause
puncture wounds and lacerations that may inoculate bacteria into deep tissues.
X-ray the bite area to exclude occult or hidden fractures, bone penetration and
animal tooth remnants. Medical imaging is always indicated for hand wounds, deep
punctures, crushing bites and bites over joints. X-rays may also show signs of
osteomyelitis. Treat infected wounds Bites on the hand have a high risk of
infection because many structures in the hand have a poor blood supply. In general,
the better the vascular supply, the easier a wound is to clean. This is the
reason why lacerations have a lower risk of infection than puncture wounds.
Administer tetanus booster if a booster has not been given in the past year.
Patients who may not have been immunised should receive tetanus immune globulin.
Educate patients about prevention of animal bites. Teach children to
approach unfamiliar pets with caution and to wash hands carefully after
handling pets. Educate on early signs of infection in bite wounds and ensure
patient returns within 24 to 48 hours for a review of the wound. To suture or not
Animal bites should be cleaned under pressure with copious amounts of saline
or water. Primary closure or suturing of lunes should only be considered in bite
wounds that can be cleansed effectively. Bites to the hands and lower extremities
which have not been cleaned within 10 hours of the bite should be left open.
Delayed primary closure is also recommended for patients who are
immunosuppressed.