What is the most humane way to euthanize a fish gas quality


There comes a time in every aquarist’s life when a fish that can no longer recover from disease or injury must be euthanized. This is no easy task, but it can be done humanely and peacefully without stress to fish or aquarist. The best method is a two-step process. First, anesthetize the fish with clove oil so that it is sleeping and unable to feel pain; then introduce a clear grain alcohol like vodka to ensure the fish will not wake up.

This method is commonly misrepresented as mixing clove oil and vodka together. That is incorrect. Clove oil must be introduced first, allowing the fish to fall asleep before introducing vodka. Vodka will be stressful for a fish that is not anesthetized.

Clove oil, or eugenol, is available at most drug stores and is sold as a toothache remedy. It has been used for years as a fish anesthetic for surgeries and tagging procedures. Clove oil will put a fish to sleep and ensure it feels no pain. The fish can wake up from this sleep if removed from the clove bath, however. The last step of adding the vodka will ensure the fish expires.

For fish up to 3 inches (7.6 cm) in length, some simple steps can be followed. The fish’s owner should add some tank water to a measuring cup or mixing bowl. The amount of tank water added to the cup or bowl should be measured and a note of it made. The fish should then be placed in the container. If the fish is in a clear cup, a dark towel placed around the cup may calm the fish.

The owner should next fill a small, clean jar or bottle with tank water, leaving some room at the top. A baby food jar or pill bottle can work well for this. He should then add 1 drop of clove oil in the jar or bottle, cap it, and shake the jar vigorously. The clove oil should emulsify, turning the water milky white.

The fish should be resting on the bottom of the tank when it has fallen asleep. It will look dead, but if watched closely, its gills will be breathing once every few seconds. If after 10 minutes the fish is still rising off the bottom and swimming intermittently, the owner should retrieve the jar or bottle of emulsified clove oil, re-shake, and add the same dose to the fish’s container. He should wait again for the fish to fall asleep.

Once the fish is asleep on the bottom, 20 to 25% white grain alcohol should be added. For example, if the fish is in 8 oz (240 ml) of water, 2 oz (60 ml) of vodka should be added. The fish should be allowed stay there for at least 20 minutes.

For large fish, the fish should be placed in a bucket or plastic tub with tank water; again, how much tank water is used should be measured. The dose for the mixture in the jar will be 10 drops of clove oil per gallon (3.78 liters). For example, if the fish is placed in 3 gallons (11 liters) of tank water, the jar should be filled with tank water and 10 x 3 = 30 drops of clove oil.

After shaking the jar vigorously, the fish’s owner should slowly add the entire mixture to the bucket or tub that contains the fish. It should then be gently mixed in. Once the fish is asleep, the previous instructions for adding 20-25% vodka should be followed.

To eliminate vodka from the procedure and overdose with clove oil alone, the fish should first be put to sleep as stated above, with the owner waiting 10 minutes for the fish to settle on the bottom. A lethal overdose of clove oil is 50 drops per gallon (3.78 liters), or 5x stronger than the initial dose that anesthetizes the fish. Using the same example, if the fish is in 3 gallons (11 liters) of tank water, the jar’s lethal mixture will include 50 x 3 = 150 drops of clove oil. It should be administered in the same way, by first shaking the jar before adding the mixture to the fish’s container.

Once the entire mixture has been added to the fish’s container, the owner should wait a few hours. Finally, he should make sure there is absolutely no gill movement by watching the gills closely for at least 60 straight seconds. If any gill movement is seen, more emulsified clove oil should be added.

Using clove oil alone is not recommended, because even though a fish looks dead it can recover once it has been removed from the bath. Clove oil is a preferred anesthetic precisely because it is hard to overdose a fish with it. Therefore, users should be especially diligent when using clove oil alone, making sure that the fish is really dead. It is much safer to use vodka as the final step.

Unacceptable methods of euthanasia include freezing, chopping, removing the fish from water, or flushing it down the toilet. These methods are slow, torturous, stressful, or violent. Clove oil followed by vodka is both inexpensive and humane; the fish goes to sleep and simply doesn’t wake up. Hopefully most people will rarely have to perform this task, but when someone does, it’s at least comforting to know your fish does not have to suffer.

of fungus. (It turned out to be Argulus) I used just 1 drop of clove to about 1 pint of water. So, I slowly added a few drops of the mixture. After a few minutes, he started spazing out like crazy. He was literally trying to suck up the sides to get out of the mixture. I figured he was just freaking because he didn’t know what was happening. It turns out that it actually killed him a few minutes later. I don’t know if armored fish are somehow different, but he completely spazed and died and I was so upset. I felt like I murdered one of my favorite fish. So, tonight I looked at one of my Purple Moscow Guppy babies. He had a tiny hair stuck in his mouth and he couldn’t get it out. So, I made the same mixture. 1 drop to about 1 pint. I added a few drops and he slowly fell asleep. I used tweezers and pulled out the hair, it was long and hard to get out. Then, I slowly took out the old water and added some of the tank water. I have been slowly doing this for about 45 minutes. Take out old water, add tank water. He looks dead and pale. But I still see his tiny heart beating. I have no idea how long to wait for him to wake up, but if he doesn’t wake up within the next hour, I’m going to euthanize him. I figure 2 hours in clean water and he should be moving. Or id this wrong? Be very careful when using clove oil to put fish to sleep temporarily. It hasn’t worked well for me so far!