Abstract: prevention of dog and cat bites. This

Abstract:

Background:

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

The
prevalence of animal bites is high, of which the vast majority are from cats’
and dogs’. There is a wide variation in severity of such bites from mild to
lethal. The evidence in the literature with respect to management does not
provide a solid ground on which such cases could be managed. Dog and Cat bites
are more common and can have dramatic consequences especially for
children. 

Objective: 

This
project is to identify current evidence in the literature on epidemiology,
management and prevention of dog and cat bites. 

This
review is aimed at clinicians who deal with dog and cat bites. The basic
principles of wound management and indications for use of antimicrobials,
tetanus and rabies prophylaxis as well as preventive education are the primary
focus of this article to help the clinicians.

This aims
at updating the management of patients who sustain a dog or a cat bite.

Materials and methods:

A
literature review on the management of animal bites was performed. UK NICE
guidelines and University of Texas bites management guidelines also reviewed.

Results:

The
available data in the literature suggest that appropriate wound management is
the most important factor for prevention of infection in dog and cat bites.
Antibiotic prophylaxis should only be given in high-risk wounds and primary
closure should be performed in low-risk wounds.

Conclusions:

Proper
assessment and wound care are the prime consideration for dog and cat bites
management.

 

 

 

 

 

Introduction

People
are increasingly keen on pet keeping, especially cats and dogs. According to
American Pet Products Association (APPA) National Pet Owners Survey 2017-2018,
68% of house has some pet and among them 86% are dog and cats (48% dogs 38%
cats)  in USA.  It is increased 25% compared with 10 years prior.
10

Animal
bites represent a significant global health issue and grew to be common public
health problem. 5 They account for 5?% of the total traumatic wounds
evaluated in the emergency department (ED) and approximately 1?% of all the ED
visits. 6 The numbers of new A&E attendances in UK is 1-2%. 7

In USA
about 4.7 million emergency department visits for animal bites every year,
about 2% of patients need hospitalization. There are 10 to 20 animal bite
related deaths, mostly from dogs, annually. 8 The running costs of management
of this bite wounds costing $53.9 million to one billion annually 8, 9.The
evidence in the literature regarding their management in many areas is still
conflicting and unclear. 5

The aim
of the review is to identify and assess the current evidence for the
epidemiology, management and education on dog and cat bites.

Methods:

A
literature review on the management of animal bites was performed. The key
search on PubMed, Cochrane library, TRIP Medical Database for dog bites, cat
bites, dog and cat bites, animal bites, management, investigation, and
education has done in the months of August and September 2017. We also reviewed
UK NICE guidelines and University of Texas guidelines.

Epidemiology:

Dog bites
account for 80% to 90% of domestic animal bites in the United States 22, 26.  Cat bites account for 5% to 15% of
animal bite wounds 1 Cat bites occur most often in adult women, usually on
the extremities.  20% of the bites
require medical attention 23, 24. The highest incidence of bites occurs in
boys 5-9 years of age. 25. In Canada between 1990 and 2007, 24 of 28 fatal dog
bites occurred in children younger than 12years of age. 27. Attention-deficit
hyperactivity disorder has been associated with an increased risk of injury.
5

The
incidence of dog bites peaks during the spring and summer seasons; they are
often unprovoked, and more than half occur at home with a dog that is familiar
to victim. 1, 2, 3 Two scenarios were identified that increased the
likelihood of a bite: (a) attempting to separate fighting animals and (b)
attempting to aid an injured animal. But sometimes may be provoked attack,
especially in children. 5. The location of bite injuries is largely dependent
on age. In younger children, the most frequently affected areas are the head,
face and neck whereas in adults extremities are involved. 4

Approximately
two thirds of patients required hospital admission at least for intravenous
antibiotics; moreover one third of animal bite victims required at least one
surgical procedure. 1. Each year in the United States, dog attacks kill
approximately 20 to 35 people, many of them young children. The reported
mortality rate in the literature ranges from 0.5% to 1.2%. 28

History taking and
assessment:

History taking: 29,40

         •                   When and where the incident took place

         •                       Type of animal and ownership (i.e.,
breed health, rabies vaccination history, behaviour, and whereabouts)

         •                       ?Circumstances around the
incident  (i.e., provoked or defensive
bite versus unprovoked bite)

         •                       ?Where on the body the bite took
place (most commonly on the upper extremities and face), and severity of the
bites, in the form of depth and exposure to underlying tissue structures.

         •                       ?Any pre-hospital treatments
including wound irrigation. (Early wound irrigation decreases the risk of
rabies infection.)

         •                       ?Review the patient’s medical
history.

         •                       ?Assess if the patient is in an
immunocompromized state.

         •                       ?Current medications (recent steroid
or anticoagulant use, Note recent antibiotics-despite flucloxacillin or
erythromycin makes super infection with resistant organisms such as Pasteurella
multocida likely)

         •                    Allergies.

         •                   Tetanus vaccination history,

         •                       Assess risk of rabies and consider
rabies prophylaxis ( specially traveller from- high risk countries of Rabies)

            ?        

Examination:

   ?   Full physical examination having the patient
change into gowns and assess the site of any unseen injuries.

   ?   If necessary, with local, general anaesthetic or
tourniquet can be used.

   ?   Stratify the wound as per the type of skin
injury and the concomitant soft tissue, tendon and bony injury; as puncture,
laceration, crushing, avulsion, dislocation of joints or fracture .

   ?   Inspect for foreign body presence.

   ?   Assess Neurovascular status of the affected part
at the site on injury and distally.

   ?   Appreciation of the associated symptoms such as
fever, rigors, nausea or vomiting.

   ?   The draining lymph nodes are to be examined for
enlargement and tenderness.

   ?   Obtain the necessary imaging to assess the
stability and integrity of the underlying structures.

   ?   Take careful documentation with diagrams of the
wound (photographs may be useful).

   ?   Children
with facial or cranial bites need cervical immobilisation until cervical
lesions are excluded            

Investigations:

         •                       ?Plain
radiography; to elicit any bone or joint involvement and the presence of any
foreign bodies.

         •                       ?Doppler
ultrasound for suspected vascular injury.

         •                       ?Wounds
Swab

         •                       ?If
systemic infection is suspected,

            o          Complete Blood Count

            o          C- reactive protein, erythrocyte
sedimentation rate, and blood cultures.

         •                       ?Computed
tomography scan ( in case of Paediatric injuries to the head or face) 29

           

Risks stratification:

It is
important to identify the high risk patients and wounds to direct the
management plan. (Table 1)

Microbiology:

The
majority of infections due to bites are polymicrobial; mix of skin commensals
of the victim and those of mouth of the animal. 38 Most common organism
isolated from dog and cat bite wounds are Pasteurella species. Among members of
the genus Pasteurella, Pasteurella canis is the most common
species isolated from infected dog bite wounds. 39 The most frequent
microorganism isolated in cat bites is Pasteurella
multocida, which is part of the natural oral flora of domestic cats. 5,
47 Some other aerobic or anaerobic bacteria also commonly isolated from dog or
cat bite wounds. (Table 2)

Pasteurella
multocida is a
small, 0.2-2 micrometer, non-motile, facultative anaerobic, Gram-negative,
pleomorphic coccobacillus. 46 (Fig-1) Culture
and sensitivities are usually available after 48 hours of incubation and if not
treated it can lead to sepsis and multiple organ failure. Some times Culture
may take up to a week to grow. 46   (Table -3)

Pasteurella wound
infection is characterized by an early onset of local intense cellulitis,
purulent discharge, and lymphangitis, usually within the first 24 hours after
the injury. 5, 46, 47

The early
onset helps to differentiate it from staphylococcal or streptococcal causes,
which usually develop after 24 hours.

Capnocytophaga canimorsus, which, although rare, can cause a serious and potentially fatal
infection specially in immunocompromised or asplenic patients.5

Management:

Antibiotics:

The
primary morbidity from animal bites is infection, but most of them don’t have
to have prophylactic antibiotics per evidence. 4, 5, 30, 36 Although there is
great discrepancy in the literature, the reported overall infection rate in
recent studies is 1-30%, with the incidence of infection in cat bites is double
than dog bites (30-50% vs 2-20%). Fortunately, with appropriate wound care the
rate of the infection drops as low as 1-2%. 5, 35, 37

Although
most of the low risk dog bite wounds do not need routine antibiotics but cat
bite wounds should be treated with prophylactic antibiotics as high infection
rate. Only wounds with greater than 5% risk of infection should be treated with
antibiotics. 5, 29, 30 . Prophylactic antibiotics were associated with a
statistically significant reduction in the rate of infection in hand bites.
17 Prophylactic antibiotics should also be considered for the high risk deep
puncture wound and wound closed primarily.5, 14 Antibiotics are not generally
needed if the wound is more than 2 days old and there is no sign of local
or systemic infection. 41  ( Table 4)

Antibiotics of choice:

The
first-line antibiotic treatment of choice for either bite wounds is the
beta-lactam antibiotic amoxicillin-clavulanic acid. 5, 28, 29, 41, 46, 47
Alternative antibiotics used for penicillin allergic patients. (Table 5)

For
children under 12 years old who are allergic to penicillin, better to seek
advice from a microbiologist. 41

Pregnant
woman who is allergic to penicillin Azythromycin could be an option.8

Erythromycin
alone is not advisable for prophylaxis or treatment of bite wounds as more than
80% P. multocida are resistant to
this antibiotics and can cause serious treatment failure. 41

If MRSA
is suspected, the first line antibiotics include, SMX-TMP (Co-trimoxazole), Doxycycline,
Minocycline, and Clindamycin. 29

The route
of administration depends on type of patients and severity of the wounds. A
study showed that 86% of cat bite wounds were successfully treated with oral
antibiotics and only 14% needed hospital admission as well as parenteral
antibiotics.47

Duration of treatment:

The
length of treatment depends on whether the wound is superficial or involves
bone or joint. Prophylactic treatment should be carried out over 5-7 days. The
superficial wounds infection requires 1 to 2 weeks of treatment. A bone or
joint involvement (Can cause osteomyelitis- Fig 2&3) requires up to 6 weeks of intravenous
antibiotics.  29, 41, 46

Treatment of established
infection:

The pus
or wound swab should send for Culture and sensitivities before starting
empirical antibiotics. The choice of empirical antibiotics are same as table
shown in Prophylactic antibiotics (Table-
5)

Localized,
superficial infection can be treated with oral antibiotics. Severe infection or
systemically unwell patients needed hospital admission and intravenous
antibiotics. 5, 29, 41, 46. Once sensitivity results are available it will
guide the management by advising appropriate antibiotics.

 Wound management:

It is
trial proven that adequate wound cleaning is very important to reduce the
incidence of infections5. Minor wounds can be cleaned with soap and water in
A&E or trauma clinic. The cleaning process might not be comfortable where
local infiltration is then due, care should be taken to infiltrate using the
intact skin around the wound.5, 29

The
irrigation volume should be titrated to the extent of the wound as per 100-200 mls per square inch of the
wound.5 It is
preferably done by using a 20 or 35 ml syringe with 19 gauge blunt needle to
provide propulsion force and enough pressure to attain proper cleansing.5, 29,
41 Normal Saline can be used for irrigation. Concentrated Povidone iodine,
hydrogen peroxide, or ethyl alcohol shouldn’t be used to avoid tissue damage or
toxicity. 42

Any
foreign bodies should be removed and devitalized or necrotic tissue should be
debrided.

Great debate exists whether to repair structures immediately, or
after a second look at 48 hours of intravenous antibiotics 19, 28, 41 But,
minor relatively clean or facial wounds can be closed primarily after proper
irrigation and debridement. 5, 28, 29, 30, 32, 34, 41, 45 Puncture wounds,
wounds older than 8 hours or with any sign of infection shouldn’t be
sutured.29 Minor animal bites in adults should be repaired in the A&E
whereas severe injuries or in case of children the repair should usually be
performed in the operating theatre. 5 Immobilization and elevation are crucial
to the affected limb.

Surgical management

The
surgical management in animal bites is to avoid immediate mortality in severe
life-threatening injuries, followed by wound debridement and thorough washout
to prevent infection. 5 In addition to debridement and washout, repair of
damaged structures, wound closure and reconstruction can be required to achieve
the best cosmetic and functional outcome.   
5      

Many
literatures suggested that, most of the animal bites can be closed primarily
after adequate surgical treatment, but special care should be given in
high-risk wounds. 5, 28, 30, 32, 34, 41, 45

Primary
suturing of wounds can improve the scar quality and cosmetic appearance without
increasing the risk of infection.5, 16, 28

Mitnovetski
and Kimble,
suggest avoiding primary closure of cat bite in hand and reviewing the
wounds in 24 to 48 hours for the possibility of delayed primary closure.45

The
facial laceration of dog bite wounds should be primary closed immediately after
formal and thorough irrigation and debridement. Comparing primary closure to
delayed one, there is no difference of infection rate.11, 32, 41

 

The bite
injuries of the hands and their related infections should be managed by a
plastic or a hand surgeon. The management of such injuries needs to encompass
appropriate antibiosis, a low threshold for surgical intervention, and early
mobilisation after a short period of splinting to afford the injured limb the
best possible chance to recover fully. 18 Associated fractures and
tendon/nerve injuries in animal bites should be managed in the same way as
open/contaminated injuries, with initial stabilization and permanent fixation
at a secondary stage. 5

Patients
with serious dog bite laceration on limbs could be benefited from NPWT
(Negative Pressure Wound Therapy). NPWT reduced the infection rate and
shortened recovery time. Low negative pressure (-75 mm Hg) is preferable than
high negative pressure (-125).12

The time
of management appeared to be critical, as early treatment resulted in lower
infection rate and improved cosmetic appearance regardless suturing or not.
Furthermore, wounds located at the head and face demonstrated better results.
16

 A short
period of splinting followed by early active mobilisation with early
physiotherapy is of benefit in order to prevent adhesions from forming that
would ultimately hinder the return of the injured limb to full range of
movement 20, 21

Pain Management

Most
patients will achieve effective pain management with over-the-counter (OTC)
analgesics.
If a patient requires more intense pain control, Paracetamol with codeine is
indicated. 29   

Immunization:

Tetanus:

Tetanus after animal bites is rare but all guidelines advise
tetanus prophylaxis, with immunoglobulin and toxoid to be administered to
patients with a history of two or fewer immunizations. 41

Administer
tetanus booster (tetanus, diphtheria toxoid Td or tetanus, diphtheria,
acellular pertussis TDaP) (if none given in past 3 years) or initiate primary
series in non-vaccinated individuals, or if vaccination status is unknown. 29
(Table-6)

For
prophylaxis of animal bites with tetanus, the cut off of tetanus doses is 3
doses. Patients with no strict knowledge of the tetanus coverage or have
received three doses or less throughout they should be receiving the tetanus and
diphtheria vaccination in addition to the immunoglobulin if needed. Whereas the
counterparts who received more than three doses would not be in need for
further coverage against tetanus.

Rabies:

Rabies is a lethal zoonosis caused by lyssaviruses, which is a
neurotropic virus transmitted from animal to humans by bite, scratch, or
licking on wound or on mucosa. 48

Rabies prone countries may needed Post Exposure Prophylaxis (PEP).
Rabies free countries usually doesn’t need PEP after dog or cat bite except
some exception (e.g. travellers, people works with imported animals). Some of
the countries already declared as rabies free including UK. According to UK
Green book (Chapter 27, v 3-0, page 331) no case of indigenous human rabies
from animals other than bats has been reported in the UK since 1902.

The indications for post-exposure vaccination,  with or without Rabies Immunoglobulin(RIG),
depend on the type of contact with the suspected rabid animal. 48

World Health Organisation (WHO) guidelines described three types
of contacts. (Table-7)

According to WHO recommendation no prophylaxis is necessary after
a grade I contact, whereas immediate vaccination and local treatment of the
wound is recommended after a grade II contact (+ RIG for immuno-compromized patients),
and immediate vaccination associated to the administration of RIG and local
treatment of the wound, after a grade III contact for patients not previously
vaccinated. 48 WHO also advised to stop treatment if animal remains healthy
throughout an observation period of 10 days or is proved to be negative for
rabies by a reliable laboratory using appropriate diagnostic techniques. 29,
48

Referral: 29,
41

            •           Dog or cat bite patient should be
referred to secondary care for following cases:

 

            ?           Most of the High risk patients
specially children, immunosuppressive and co-morbid patients. (Table 1)

            ?           Most
of the high risks wounds (Table 1)

           
?           Facial wounds
(excluding very minor wounds).

            ?           Wounds which might benefit from
closure.

            ?           Bites where the severity of the
injury is difficult to assess.

            ?           Bites that might need reconstructive
surgery.

           
?           Bites to poorly
vascularized areas eg ear cartilage/nose cartilage.

 

            •           If an animal has bitten a child,
consider the possibility of poor parenting and supervision. Follow local
policies for referral of children considered at risk.

            •           If there is a possibility that the
person has been exposed to rabies, seek immediate
advice from the Virus Reference Department of the Health Protection Agency.

 

Monitoring and
Follow-Up  29,
41

All
patients should be followed up or monitor closely wherever managed by primary
care or discharged from secondary care. A leaflet can be better to help the
patients understand better and engage in to the management process.

For
non-infected wounds, Patients should be warned about possible infection and
educate about the sign and symptoms of infection and when to contact hospital
without delay.

For
infected wounds- Patients should routinely review in 24 and 48 hours time  to check the response of treatment. Advise
the patients to attend for review if getting worse and feeling unwell.

For post
operative patients- Clear post operative instructions about wound care, follow
up plan and  physiotherapy should be given
in written.

PEP for
Rabies- Advise the patients to observe the offending animal (if possible) and
attend for vaccination as per schedule.

Patient and Family
Education

Patient
and family education aims to involve them in management of current problem as
well as prevention of future bites.

Education
about wound care, mobilisation and early identification of complications is
important. Specially about the infection related to different animal bites.
Patient also should be informed what to do if they are concerned about
something.

Establish
treatment goals with the patient including preventing infection or treating
existing infection, reducing scarring, treating pain, preventing tetanus and
rabies infections, and reducing psychological trauma.29

Educate
about the importance of finding and observing the offending animal relation
with rabies vaccination. 29

There is
no direct evidence that educational programmes can reduce dog bite rates in
children and adolescents. Educating children who are less than 10 years old in
school settings could improve their knowledge, attitude and behaviour towards
offending animals.13

Children
who watched the educational videos of testimonials on dog-bite prevention had
increased safety knowledge, higher perceived vulnerability, and less risky
simulated behaviours with dogs compared with the comparison group. 15

Following
advice may help to prevent future bites:41

         Avoid-

            ?           Running or screaming in the presence
of a dog.

            ?           Greeting a dog with an outstretched
hand.

            ?           Petting a dog without letting it
sniff them first.

            ?           Humanising the dog (for example
allowing it to sleep on the furniture, beg for food), and do not hug or kiss
it, as this makes it more difficult for the dog to distinguish between animal
and master, and may increase the risk of biting.

Conclusion:

In this review, we tried to identify and
assessed the epidemiology, patient assessments 
and standard of management and prevention of dog and cat bite wounds.

CONFLICT OF INTEREST

The
authors confirm that this article content has no conflict of interest.

ACKNOWLEDGEMENTS

Declared
none.

Comments are closed.