Infected animal and human bites

The mouths of animals and humans carry many bacteria. A bite punctures the skin and can inject those bacteria into deeper tissue, where a closed puncture wound seals them in. Cat bites are small but deep, so they are especially prone to infection, whereas dog bites tend to crush and tear tissue. Human bites carry a mixture of oral bacteria and, uncommonly, blood-borne viruses.

Infection usually declares itself within a day or two, with pain, swelling and warmth. Hand bites are particularly risky because infection can spread along tendon sheaths and into joints.

The NHS advises cleaning the wound with soap and warm water and gently squeezing it so that it bleeds slightly, which helps flush out bacteria. If bleeding is heavy, press on it with a clean cloth. Cover with a sterile dressing, and use paracetamol or ibuprofen for pain if suitable for you. Do not suck the wound or close it with tape or glue yourself.

• Wash thoroughly under running water with soap for several minutes.

• Control bleeding with firm pressure.

• Cover loosely with a clean dressing.

• Note the animal, when and where the bite occurred, and the animal's vaccination status if known.

The NHS recommends contacting NHS 111 if the bite is hot or swollen or has fluid leaking, if you have a fever, if it smells unpleasant, if the bite is on the hands, feet, face or head, if it is a human bite, or if your tetanus vaccination is not up to date. Go to A&E for a large or deep wound or if you cannot stop the bleeding. If a body part has been severed, wrap it in tissue, place it in a plastic bag on ice and bring it to hospital.

People with diabetes, a weakened immune system, no spleen, poor circulation or an artificial joint are more likely to develop serious infection and should seek advice promptly, even for a minor-looking bite.

The NHS says healthcare professionals thoroughly clean the wound, may close it with stitches or adhesive when appropriate, and may prescribe antibiotics. They also assess the risk of tetanus and rabies. Deeper or contaminated wounds are often left open or only loosely closed to reduce the chance of trapping bacteria. A hand or face bite may need specialist review, and an X-ray if a bone or joint could be involved.

For human bites the NHS notes screening for hepatitis B, hepatitis C and HIV is offered, which involves blood tests and, where needed, preventive treatment or vaccination.

Tetanus bacteria live in soil and manure and can enter through wounds. The NHS says the tetanus vaccine is part of the routine schedule starting at 8 weeks, with boosters in childhood and adolescence; if you sustain a dirty wound and are not fully vaccinated, seek urgent medical help. Symptoms such as a stiff jaw, muscle spasms or breathing difficulty need 999.

Rabies is not present in UK land mammals, but it is a risk in many countries. The NHS states you can get rabies if bitten or scratched, or if an infected animal licks your eyes, nose or mouth, and that you should get medical help as soon as possible abroad. Treatment with vaccine doses and, where needed, rabies immunoglobulin is usually very effective if started quickly, but once symptoms appear the infection is almost always fatal. Pre-travel rabies vaccination is available privately for higher-risk trips.

Never leave young children alone with animals, learn the warning signs in dog body language, avoid approaching stray or wild animals abroad, and do not feed monkeys or touch bats. Keep your own tetanus vaccinations up to date and consider rabies vaccination before remote or prolonged travel in endemic areas.