If you think your goldfish is dead, there are a few things you can do to confirm it before flushing it down the toilet.
1. Check for signs of life. Gently touch your goldfish to see if it responds. If it does not move, it may be dead.
2. Look for a heartbeat. Hold your goldfish up to your ear and listen for a heartbeat. If you do not hear a heartbeat, it may be dead.
3. Put your goldfish in a bowl of fresh water. If your goldfish is still alive, it may revive in the fresh water. If it does not revive after a few minutes, it may be dead.
If you are certain your goldfish is dead, you should bury it or compost it. Do not flush it down the toilet.