Animal and human bites

A bite wound is deceptive: from the outside it is a couple of tooth marks that stop bleeding within a minute, but a tooth works like a needle. It drives saliva carrying dozens of species of bacteria deep into the tissue, and the narrow track through the skin closes over the top almost at once. That is why a bite is handled differently from a cut: it is washed for a long time, it is not stitched up in a hurry, and it is looked at again a day later. What follows concerns bites from dogs, cats, other animals and people that have broken the skin.

The first minutes: water matters more than anything

Only one thing reliably lowers the risk of infection straight after a bite, and that is generous washing: not a wipe with a tissue, but a stream of water and soap, several minutes without stopping, into the wound itself.

• Wash the wound and the skin around it with soap and running water for at least five minutes; if it is a deep puncture, aim the stream into the track.
• Remove whatever rinses out easily: hair, soil, a chip of tooth. Digging deep with tweezers is not a job for the kitchen table, it is done in a treatment room.
• If the wound oozes a little, do not stop the bleeding at once: blood carries the dirt out. Squeezing the wound on purpose or sucking it with your mouth achieves nothing.
• If bleeding is heavy, press with a clean cloth, hold the pressure and raise the injured part.
• Then dry the surrounding skin, apply an antiseptic to it and cover the wound with a dry dressing, without binding it tightly.
• For pain, paracetamol or an anti-inflammatory from the NSAID group will do; aspirin must not be given to children or teenagers.

Do not seal a puncture under an airtight plaster, do not pull the edges together yourself, do not pour spirit into the wound, and do not count on it healing by itself if the bite came from a cat or landed on a hand.

When emergency care cannot wait until morning

Do not leave it until the next day if:

• the wound is wide or deep, has a flap of skin, or its edges will not meet;
• the bite is on the face, neck or head, or next to a joint, and likewise any bite on a hand or a finger;
• bleeding does not stop with pressure;
• a finger or a limb has gone numb, turned pale or moves badly, which means a nerve, a vessel or a tendon has been damaged;
• the bite came from a stray, unfamiliar or wild animal, from a bat, or from any animal abroad;
• the person has diabetes, no spleen, weakened immunity, is on chemotherapy, or has an artificial joint or heart valve;
• the person bitten is a baby under one year old, or someone who cannot describe what they feel.

Call 112 for heavy bleeding, a bite to the neck or face with difficulty breathing, loss of consciousness, or an attack by a large animal. If a part of the body has been torn off, wrap it in a clean damp cloth, put it in a bag and pack ice around the outside of the bag: sometimes it can be reattached.

What a wound looks like when infection sets in

On the first day every bite hurts and reddens along the edge, and that is expected. What should worry you is different: on the second or third day it gets worse instead of better.

• the pain grows although the wound should already be settling;
• redness spreads beyond the bite, the skin swells and feels hot;
• cloudy or foul-smelling fluid comes out;
• a red streak runs from the wound and the nearest lymph nodes are enlarged and tender;
• chills or a fever appear;
• the joint next to the bite swells and will not bend, or a finger will not straighten.

A cat bite on the hand can flare up within hours, and there the count is in hours, not days. Separately there is a rare but headlong emergency: pain far out of proportion to how the wound looks, redness advancing while you watch, skin turning dark or blistering, the person weakening fast. That is a deep tissue infection spreading into the blood, and it needs 112 and an operating theatre.

Why some bites are worse than others

• Cat. Thin sharp teeth make a deep narrow track, barely visible from outside, and inject a bacterium that inflames quickly. Roughly one bite in three becomes infected, so an antibiotic is usually started straight away.
• Dog. The teeth tear and crush more than they pierce: there are often several wounds, and part of the tissue is left pulped, which heals worse. In children a dog bite lands on the face more often.
• Person. Human saliva is no safer than a dog's. The most treacherous of all is a grazed knuckle after a punch to someone's mouth: the little wound over the finger joint looks like nothing, yet the tooth has had time to open the joint or the tendon sheath. Those wounds are for a surgeon to look at.
• Site. Hand, foot, face, the area of a joint and the genitals: the tissue under the skin is thin and tendons and joints lie close, so inflammation travels inwards sooner.
• The person's own health. Diabetes, weakened immunity, cirrhosis, a joint replacement. Without a spleen, even a small dog bite can turn into severe blood poisoning, which is why the antibiotic is begun the same day.

Rabies: the part that is not decided at home

Rabies is rare, but it leaves no room for choice: once the illness has begun, the person can almost never be saved. Vaccination started before the first symptoms, on the other hand, protects reliably. The risk is judged by a doctor, taking the country and the circumstances into account. You must seek advice if:

• a wild animal bit or scratched you: a fox, a hedgehog, a woodland rodent, anything that let you come close far too easily;
• there was any contact with a bat, whose bite or scratch can go unnoticed and which is the main source of the virus in Europe;
• the bite happened outside Europe, especially in Asia, Africa or Latin America: street dogs and cats, monkeys around tourist sites;
• the animal is unknown, behaved strangely, or cannot be checked;
• saliva landed on a fresh scratch or on a mucous membrane: eye, lips, nose.

A vaccinated pet cat or dog in a country free of rabies carries no risk, but that is confirmed from the vaccination record, not from the owner's memory.

What the doctor will do

Examining a bite is above all about depth. They will check whether the fingers move and whether sensation is intact, wash the wound under pressure, numb it if needed and remove crushed tissue; if a fragment of tooth or a fracture is suspected, an X-ray is taken. Then four questions are settled, and the sooner the wound arrives, the easier each of them is.

• To close it or not. Punctures, hand bites and old or dirty wounds are usually left open under a dressing: a wound stitched tight becomes a closed incubator. The face is stitched more often for the sake of appearance, but even there it is washed with particular care first. Sometimes the wound is closed later, once it is clear there is no infection.
• Antibiotic or not. Not for everyone: a superficial scratch from the family dog is managed without one. It is prescribed for cat and human bites, for wounds of the hand, face and joint area, for deep or dirty wounds, and for people with weakened immunity. Usually it is a broad-spectrum penicillin with a beta-lactamase inhibitor, and the course is finished to the end.
• Tetanus cover. They check when the last dose was given; for deep and dirty wounds in unvaccinated people, ready-made antibodies are added.
• Rabies and the surgeon. Where there is a risk of rabies, a course of vaccination is started, and for severe wounds immunoglobulin is added. Bites of the hand, joints and face are reviewed by a surgeon, and the person is asked to come back for another look in a day or two.

If the bite came from a person

Here what is carried in blood is added to the picture. Hepatitis B genuinely does pass on through a human bite; hepatitis C and HIV do so only exceptionally, but they are discussed too, especially if the wound is deep, has bled, and the person who bit had blood in their mouth. The doctor will ask about hepatitis B vaccination, offer the vaccine or immunoglobulin where appropriate, and request blood tests at once and again several weeks later. Sometimes a short course of medicines to prevent HIV is also considered, and that is decided within the first hours. One more thing: a human bite is often the trace of a fight or an assault, and it is worth saying so plainly, because the help needed is not always help for the wound alone.

Online consultation: what it can do

Deciding where to go and how urgently works well at a distance. The doctor goes through who bit you, where and when, and what you have already done, then says whether care at home is enough or whether you need to be seen the same day. From a photograph they can judge how the wound looks on the second or third day and point out what should raise the alarm. Online you can also clarify the timing of tetanus and rabies vaccination and go over the treatment and dressings you have been given. What a remote appointment does not replace is washing out the wound, stitches and the first examination of a deep bite: if the wound is bleeding heavily, if the hand or face has been bitten, or if the animal was wild or unknown, what you need is emergency care and not a message.

This material is for information only and does not replace medical advice.