Animal bites in children – what to do

Bites and scratches – in what ways do they differ?

Let me just put a few definitions out here:
Bite – this one is obvious. This happens when the animal’s teeth penetrate human skin and cause a wound. The wound may be small and superficial, but animal bites can also lead to severe and extensive wounds.
Scratch – this is a wound that occurs because of animal nails. Here too, scratches can be superficial or deep and extensive.
Lick – animals can also transfer infections through licking. It is important to determine whether the skin that was licked was intact or wounded prior to the lick and whether the licking involved mucous membranes such as the eyes or mouth.
What about contact with animal secretions? This is also an interesting topic to discuss, but it is beyond the scope of this post.

Everyone knows that the deeper the wound, the greater the risk of contracting infections, and the more extensive the tissue damage. You can’t really compare the implications of a real bite to a minor scratch. And there is no comparison between the licking of a bleeding wound, when a lot of saliva is present, and the licking of intact skin.

Does management depend on the animal involved?

The truth is that it does. When I sat the Infectious disease board exam, I knew had all these different names of bacteria and the corresponding mouths of animals that they are present in memorized. I even knew the bacteria you could find in the mouths of a hippopotamus and lion! Imagine that. I will obviously not be going into such details here. That isn’t really the point of this post.
There are, of course, differences between the bites of pets like cats and dogs, which represent most of the bites we encounter, and those of rodents, wild animals and other exotic animals.

How do animal bites differ?

They differ in the type of usual bacteria present in their oral cavity and on their nails (note that cats by licking their nails and so the bacteria present in their mouth are transferred to their nails). In addition, different animals from different geographical locations may carry different viruses (for example, macaque monkeys that you see in Thailand), and this is also how rabies is transmitted.
What about the bites of the most dangerous animals out there (humans)? More about this to follow below.

Does an aggressive animal bite differ from a bite by a non-aggressive animal?

Yes. Whether or not the animal was provoked prior to the bite is taken into account when the need for a rabies vaccine is considered. There is also a difference between a bite that follows the provocation of an animal, which could also happen when one is playing with it, and a random animal attack and bite.

Part 1: What are the first aid principles for animal bites/scratches?

First aid – evaluation of the initial status and assessment of the need for emergency care. There is an obvious difference between a mild kitty cat’s bite and that of a Pitbull that may leave the child with extensive tissue damage and blood loss. One should always start with primary wound care, washing the area, and more washing and more washing. Prolonged washing with soap and water (for a duration of at least 15 minutes) aid in reducing the risk of infection and the transmission of rabies, simply by removal of the saliva of the animal from the wound. It is as simple as that.
After washing the wound, it is time to sterilize the area. You can use any sterilizing solution sold at your local pharmacy. Stitches – generally speaking, unless the wound is on the face, we prefer keeping bite wounds open and would rather not aid in the healing process by using sutures. Why is that? Because of the risk of infection.
Facial bite wounds – in order to minimize scarring and reach the best possible aesthetic results, we tend to suture facial bite wounds following surgical cleansing of the wound (debridement of the margins) and also because the risk of infection on the face is lower, probably because of the abundant blood supply to the face.

Part 2: Prevention or treatment of infection of bite/scratch wound

I often have parents question me about whether they need to give their children antibiotics following a bite, and if so, which antibiotic I would recommend.
So let’s cut to the chase – if the wound is infected, see the image above for an example of cellulitis (and if you are not familiar with this term then I urge you to read the post about it here) on a child’s hand following a catch scratch, then there’s no question about it. But are prophylactic antibiotics (antibiotics given prior to the development of infection in an attempt to prevent it from happening) required? Not necessarily. If it is a very superficial scratch then topical treatment and monitoring is obviously sufficient.

On the other hand, oral prophylactic antibiotics are reserved for cases that involve significant bites and scratches, including:
– Wounds that underwent primary closure (suturing a wound, instead of leaving it open for secondary healing, increases the risk for infection).
– Wounds that lead to extensive tissue damage.
– Wounds on the hands, genitals or on the face.
– Wounds in joint and bone areas – where there is little subcutaneous tissue and there is a risk that the infection will easily spread to the bones. A classic example is that of a cat bite since a cat’s teeth are long and are able to penetrate deep into the flesh and reach bone. This is why sometimes cat bites are an indication for prophylactic antibiotic treatment.
– Wounds in areas that are prone to infection – for example in bodily areas that are edematous or contain extensive hematomas (where lymphatic drainage is not optimal and there is an increased risk for infection).
– Wounds in children with immunosuppression or poorly controlled diabetes.

What antibiotic is required for prevention of infection following animal bites?

So, this is a special situation where we are interested in covering both oral bacteria and bacteria commonly found on skin. The antibiotic of choice is therefore amoxicillin-clavulanic acid. If you have already read my chapter about skin infections, you probably know that we prefer using cephalexin over amoxicillin-clavulanate for regular skin infections. But in the case of animal bites, cephalexin is inappropriate as it does not cover the bacteria normally present in the mouths of the animal involved. For those who are allergic to penicillin, a combination of antibiotics that may include trimethoprim-sulfamethoxazole, clindamycin or ciprofloxacin can be administered.
For how long? If the antibiotic is being given for prevention, a 3-5 day course is sufficient provided the wound is monitored by a physician that ensures an infection doesn’t developed.
Remember that if the antibiotic was prescribed following the development of infection, the required duration of treatment is one week and sometimes may even be longer, depending on the extent and depth of the wound. Here too, a pediatrician’s follow-up is required.

Part 3: Which vaccines should be given following an animal bite wound?

The 2 vaccines that need to be considered are Tetanus and Rabies vaccine.

Tetanus vaccine following an animal bite

Bite wounds are considered a risk factor for bacterial infections due to tetanus (a bacteria named clostridium tetani) which is a bacteria found in the mouth of many animals as well as on their nails.
Therefore, anyone affected by an animal bite needs to be assessed for the need for tetanus infection.
Fortunately, I’ve already covered the topic regarding who needs a tetanus vaccine and when. Refer to this link in order to see if you or your child need a tetanus vaccine (active or passive).
Remember that any bite that isn’t very superficial is considered one that isn’t minor (read the chapter about tetanus to understand what this really means) and therefore:
– In a child/adult that has previously received 3 or more doses of tetanus vaccine, and 5 years have passed since the last dose, a booster is to be given.
– In a child or adult who is not vaccinated (or has received 2 doses or less) or if the vaccine status is unknown – in a wound that is not minor, a passive vaccine (i.e immunoglobulins) is to be given immediately in addition to the active vaccine. The tetanus vaccine schedule needs to be continued afterwards.
Please read the chapter about tetanus thoroughly, and in any such cases, reach out for a doctor’s consult.

Rabies infections after a bite wound

What is rabies?
Rabies is a viral infection that affects mammals. Anyone who gets it and doesn’t get vaccinated will die, because we do not have any treatment for it.
The rabies virus spreads through the nervous system to the brain, where it leads to a brain infection that leads to death. That is why the rabies vaccine is considered life-saving.
Around the world, approximately 30,000 – 70,000 adults die from Rabies every year. The natural presence of Rabies varies geographically.
The rabies virus is present in the saliva and central nervous system of infected animals. The transmission occurs when the virus encounters a nerve end, after having been exposed to skin or mucous membranes through a bite or scratch. Bites are the most common mode of transmission, but transmission can also occur following animal licking of human mucous membranes or wounded skin. Note that scratching with nails that are covered with saliva is a rare mode of transmission. The virus cannot be transmitted through the licking of intact skin or through petting or touching animal body secretions. However, the local medical authority in charge of infectious diseases and vaccines should always be contacted for a consult.
Wild animals are always considered to carry rabies. Also, any wounds caused by bats, as small as they could possibly be, will always present a high risk for infection.
In other words, leave it to the specialists to make the right decisions for you.
Since the local medical authorities are those that usually make decisions regarding whether a child needs a rabies vaccine or not, for any sort of animal bite I would suggest you refer to your local authority to get the best guidance regarding management. Only they can determine whether the animal needs to be isolated and whether the child needs to get vaccinated.

When is the rabies vaccine administered?

The rabies vaccine is given to the child at risk as soon as possible if there is a risk for infection, when it isn’t possible to track the animal or because of the extent of the wound, the type of exposure that occurred or the type of animal involved.

What type of vaccines do we have for Rabies?

The oldies remember the old, infamous Rabies vaccine. Lots of painful injections. It is not the same as the vaccine we give today.
Passive vaccine – i.e immunoglobulins. This is usually given together with the first dose of the active vaccine to give immediate protection while the natural antibodies driven by the active vaccine develop. Part of the vaccine is injected into the wound while the remaining content is injected into muscle.
Active vaccine – this is an inactivated vaccine administered intramuscularly on days 0, 3, 7 and 14 following the bite.

My neighbor says his dog is vaccinated for Rabies. Does this mean everything is O.K?

No and no!
First of all, only the local medical authority is allowed to determine whether a dog is considered vaccinated. The fact that a dog received one dose of the vaccine once, like 7 years ago, does not mean it is vaccinated.
Second of all, even if an animal was properly vaccinated recently, it doesn’t mean they are fully protected and are unable to infect others.

What should I do if my child was bit by their classmate?

Of course, talk to their teacher first.
Practically speaking, the approach is similar to that of animal bites. Start with topical treatment and take into consideration extent of wound etc.
Antibiotic treatment may be considered. The antibiotic recommended is the same as the one given for animal bites despite the fact that the bacteria found in human mouths differ from those in other animals.
Vaccines – human bites pose a risk for tetanus infection. On the other hand, there is obviously no need for rabies vaccine.

Are there other infections that can be transmitted through bites?

Sometimes I get asked about the risk of transmission of HIV or Hepatitis B and C through animal bites. Fortunately, the risk is very very low and is only present when there is a significant exposure to infected blood. Therefore, routine treatment for these infections is not required for animal bites and are only considered in very rare cases.
Also, remember that children get vaccinated for Hepatitis B as part of their routine vaccine schedule in their first year of life.

To summarize, this is a very important chapter that I get asked about a lot.
Remember the three principles of management: first aid, infection prevention and vaccine consideration.
If there are any doubts or if you have any questions, always consult with your doctor and come to a joint decision.