How to Humanely Put a Fish down

Like most animals, it is sometimes necessary to end a fish’s life prematurely because of illness or disease. The easiest way to kill a fish quickly is to destroy the fishes brain with a sharp implement. You can also euthanize the fish quickly by severing its spinal cord just behind the head. Carrying out this procedure must be done very quickly so as not to cause any stress to the fish. If you are not confident enough to dispatch a fish this way then use an anesthetic to put the fish into a deep sleep and then carry out the procedure. If you still can’t bring yourself to physically cut the fish then an overdose of anesthetic can be used to euthanize the fish. The following instructions show you how to euthanize a fish using clove oil.

Clove oil is readily available at various outlets such as Boots. I think I paid about £1.30 for my little pot.

  1. Firstly, move the fish into a smaller tank, a baby bath or bucket – something that can be thrown away or easily cleaned.
  2. Put 3 drops with a half pint of water and shake very well, so the oil and water make a fusion – otherwise the oil will just float on top of the water and for the euthanasia to work the fish has to get the oil into its system. I must emphasise that it is very important that you mix the water with a clove oil properly to avoid it simply floating on the surface like any oil will.
  3. Add the mixture to the water that the fish is in (1 gallon of water should be more than enough) and stir it around slowly with your hand. The fish should become lethargic and sleepy.
  4. Add another mixture of 2 to 3 drops of oil in water. When the fish goes “belly up” it is asleep – not dead.
  5. Then add 3 more drops of clove oil.  The fish feels nothing, it is very peaceful and humane. It seems mad that a few drops of something can have such an effect, but it IS very strong. Don’t make the mistake of thinking that if you initially put more in it will act quicker – it will only freak the fish out – it has to be done gradually so the fish doesn’t notice the change in the water.

This procedure can take anywhere from 30 minutes, to a couple of hours, sometimes a little more.  If after one hour you still see some gill movement which indicates the fish is not dead, you can add a few more drops of clove oil.  Eventually, the fish will succumb to the overdose and pass away peacefully.


Freezing fish, or putting them in very cold water is often thought to be a humane way of despatching fish. This is not the case, this is purely done to preserve the quality of the flesh for eating.

Killing fish by flushing them down the lavatory, boiling, or just leaving them out all the water until they die is very inhumane. A person may be committing an offence if they cause the animal pain and distress prior to, or during the killing procedure.

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