Domestic cats have a huge number of bacteria in their mouths which can very easily cause wound infections in other animals, including humans, when they bite. If your cat does bite you, you should immediately wash the area under running water and stop any bleeding by applying firm pressure with a dressing for up to five minutes. It is recommended that you ALWAYS seek medical attention after being bitten by a cat as a course of antibiotics will often be required.
The consequences of not seeking medical attention include severe wound infections, fever and occasionally septicaemia (blood poisoning). Some serious wounds, especially those involving joints, may need surgical drainage and repair. If your cat is bitten or scratched by another cat, similar signs can be seen so in these circumstances you should always seek prompt veterinary attention.