Personal tools
You are here: Home / Disease / Going on up to the Fishtank in the Sky

Going on up to the Fishtank in the Sky

by Emma Turner last modified May 20, 2007 05:55 PM
Fish euthanasia article - by Emma Turner.

         Images for Euthanasia article

     Euthanasia is a very difficult topic, and one which will no doubt affect every fishkeeper at some point during the years spent caring for their fish.

      For loach-keepers in particular, this may be a very difficult decision due to the longevity of some species and our subsequent attachment to our bottom-dwelling friends. On the one hand, we want to do the right thing for a fish that is obviously suffering and beyond help, yet the bond we share with them can also cloud our judgment and result in us putting off this act of kindness in an unrealistic hope that the fish may make a miraculous recovery.

      Of course we are all different and some people show more emotion or are more sensitive than others. There are those who will be reading this and thinking nothing of it; yet there will also be those who might have had difficulty in even opening up this article. Whatever your disposition, it is asked that you show respect for the poster who wishes to discuss this subject in the forums, as that person may be having to make, what is for them, a potentially heartbreaking decision.

      If you are at the point where your fish is clearly suffering for whatever reason (illness, injury or symptoms due to old age), and you feel that they are not responding to various treatments, then it is probably time to put the fish to sleep. As difficult as it may seem, it will be the kindest thing you can do for them. In the next few paragraphs, I will discuss various methods and explain why some are ultimately kinder than others:


Clove Oil

      The use of clove oil based products within the fishkeeping hobby first came about as a sedative and mild anaesthetic used when handling large fish such as koi carp. A low dose of this product effectively sends the fish into a drowsy state, which is very useful, for example, when wanting to take skin scrapes, carry out vaccinations, or some other situation which would otherwise be very traumatic for the fish. Clove oil has to be administered in the correct dosage in order to sedate the fish. A massive overdose will send the fish into a peaceful deep sleep, from which it will not regain consciousness and will pass away painlessly. This method, which relaxes and calms the fish as it works, is the kindest way in which to euthanize a terminally sick fish.

      In the UK, the leading product of this type is ‘Koi Calm’ by NT Labs and is available from all good aquatics stores. In the US, Drs Foster & Smith offer an equivalent liquid by the name of ‘Euthanase”. Generally, these products are inexpensive, have a very long shelf life and take up very little room in the cabinet. In my opinion, every fishkeeper should keep a bottle of this handy in case unfortunate circumstances necessitate its use. This is the method that the Loaches Online team wish to recommend to other fishkeepers.

      Because of the relative safety of Clove Oil, a decent amount must be added to the water for successful euthanasia. Where directions for euthanasia are not given on the bottle, a suggested dose is at least 5 times the amount stated on the bottle for that of pure sedative use. There is a risk of ‘recovery’ if the solution is not strong enough. These products must firstly be added to a small volume of water and the container shaken vigorously to create a white emulsion prior to this being added to the container holding the fish. It is advisable to leave the fish in the solution for several hours and observe, at regular intervals, for any gill movements.

      Veterinary surgeons also use anaesthetic products, with similar effects, known as MS222 (Tricaine Methanosulfonate) or Benzocaine hydrochloride.

      If none of the aforementioned products can be sourced (check mail order companies if your local stores do not carry them) you can also purchase pure Clove Oil (Eugenol) from some health stores and pharmacies. An approximate guide to dosing is 20-25 drops per litre. Overdosing is obviously better than under-dosing in this situation. Follow the directions mentioned above of leaving the fish in the solution for some time, observing for gill movements.

      Note: As Clove Oil can dissolve polystyrene, it is not recommended that you carry out this process in a poly-box or similar. Instead use a proper fish bag or glass container.

                    DSCN0607.JPG              Euthanase.jpg


      For some years, a rather inaccurate myth has circulated with regards to freezing terminally ill fish. It has been said that placing your fish in a container of tank water and then placing this in the freezer to send the fish to sleep is a kind method. Unfortunately, this is not the case, and the fish will suffer a long drawn out and painful death as the temperature drops and the liquids inside its body start to crystallise whilst the fish is still conscious. We cannot recommend this as a pleasant end to your fish’s life.



      Understandably, not everyone would be able to euthanize their beloved pet via decapitation. Many experts claim that severing the spinal cord just behind the head with a sharp knife, if carried out swiftly and correctly, is the best method to use, yet others claim that there are moments afterwards when the fish is still conscious and aware. If the so-called experts aren’t 100% sure, coupled with the possibility of human error, then we at Loaches Online are not happy to recommend this method to you. Even a very brief moment of consciousness after the event is a moment too long for us to feel comfortable with.



      Again, this would be considered a very upsetting method by many people. The idea is to strike the fish on the head with a heavy blunt object, stunning the fish and instantly ceasing its brain function. However, as stated above, if the fishkeeper accidentally carries this out incorrectly and the fish’s brain is still left partially functioning, it is going to be suffering beyond belief.


Other Methods

      From time to time, a number of completely unacceptable and gruesome methods of euthanasia crop up on various fish forums, which some fishkeepers will swear by. Anything from dropping the fish into boiling water, pushing the fish into the garbage disposal unit, flushing the fish down the toilet, and leaving the fish out of water in order to suffocate are quoted. These methods are by no means pain free and here on Loaches Online, we feel they are totally unacceptable and do not advocate their use.


Safe Disposal of Dead Fish

      Once your fish has passed on, the body should be disposed of in a safe and responsible manner. Of course many fishkeepers may choose to bury a long-term pet in the garden. For those who don’t, it is recommended that you wrap the body in newspaper sprinkled/soaked with a household disinfectant, and then tightly seal in 2 or 3 plastic bags before placing in the waste bin. Dead fish should never be flushed down the toilet or released into natural waterways as diseases could be introduced to native fish populations with disastrous results. Alternatively, wrap the body in a plastic bag and take to your local veterinary practice for disposal via incineration.


And Finally……

      We wish to reiterate that questions/suggestions on this emotional subject on the Loaches Online forums are answered with the utmost respect for that poster having to make a difficult decision.

Thank you.


Disclaimer: This Loaches Online article is for information purposes only and is accurate to the best of our knowledge. Reproduction of this article is not permitted. No liability will be accepted for any problems following on from the replication of the actions described.

Clown Loach Logo - Animated

< Back to Disease Articles Page

Document Actions