When a cat’s back arches, it may be a sign of pain, vomiting, stretching, or aggression. You should pay attention to the cat’s diet management at ordinary times. Do not feed it food that is too oily or salty to avoid irritating the gastrointestinal tract. Regularly detoxify the cat. insect. In addition, cats will also arch their backs when they are threatened. This is self-defense and they will attack at any time.