It is currently widely accepted that the most humane way to euthanize a sick guppy is to use clove oil. When a guppy is exposed to clove oil is sufficiently high quantities it first becomes unconscious before stopping breathing. Clove oil is considered the most humane way for home aquarists to euthanize a guppy.
Guppies are one of the most popular fish in the fishkeeping hobby. They have been popular since the late 1960s and their popularity stems from their easy-going nature, ease to breed, and hardiness. Even fish as hardy as guppies do occasionally become sick, and when they do, there are occasions medication won’t cure them. In these circumstances, we may need to euthanize a guppy.
I have been keeping guppies for over 30 years. In that time, thousands of guppies have passed through my fish room. Needless to say, there have been occasions when I had fish that I just could not treat successfully and this guppy had to be euthanized.
Euthanizing A Guppy With Clove Oil
If you were to take your sick fish to a veterinary surgeon, they would use strong anesthetics to euthanize your fish. The advantage clove oil has over medical grade anesthetic is that it is available over the counter in chemists and medical supply stores.
To euthanize a guppy with clove oil you need around 40mg of clove oil, a small container, and around 1 liter of aquarium water.
Instructions For Euthanizing A Guppy With Clove Oil
Confirming Guppy Has Died
If you observe your guppy closely, you should see there are no gill movements. It is generally accepted that after 10 minutes of no gill movements the guppy has died. It is important to make sure your guppy is dead before disposing of the body.
When I have had to euthanize a guppy, I always prefer to leave it in the water/clove oil mix for as long as possible, just to make sure it is completely dead.
Ways NOT To Euthanize A Guppy
If you do a quick search on the internet you will find a whole bunch of crazy ideas about how to euthanize a guppy. You should NEVER use any of the methods listed below.
Flushing down the toilet
Flushing a live guppy down the toilet is not a humane way to euthanize it. If you flush a live guppy down the toilet it will end up either suffocating in the pipe or having its gills severely burnt by chemicals in the wastewater. Either way, not a humane way to euthanize a guppy.
Ice or boiling water
Despite what you may read elsewhere, submerging your guppy in ice, or worse, boiling water does not allow your guppy to ‘slip away quietly’. I would imagine it is as painful to drop a guppy into ice or boiling water as it would be for a person.
Removing a guppy from its water and allowing it to suffocate in the open air is a slow and no doubt painful way for a guppy to die. When you consider it is the equivalent of holding a person underwater until they die, you can see it is not very pleasant.
It is never nice when we have to euthanize a guppy. The best we can hope for is to do it as quickly and peacefully for the guppy as possible. According to everything I have read, using clove oil appears to be the most humane way most of us home hobbyists can euthanize a sick guppy.