A cat's convulsions may not necessarily lead to death. If a cat convulses due to poisoning, heart disease, heatstroke, or brain tissue damage, it will die within a few hours; but if it is due to parasitic infection, Convulsions caused by hypocalcemia, epilepsy, etc. will not lead to death.
Tips:
When you find a cat convulsing, it is best to send the cat to the pet hospital for examination and treatment immediately, so as to save it. Hopefully it will be bigger.