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Euthanasia of fish

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#1 Dragonslair



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Posted 27 July 2003 - 01:17 PM

For the aquarist the saddest job is that of euthanasia. This however is necessary in some cases, to avoid unnecessary suffering and pain to your fish.
A lot has been written about this topic and there are many divided opinions. The opinion that I am about to give you is from an ichylogist point of view.

Acceptable Methods of Euthanasia.
When considering euthanasia bear in mind that fish are capable of experiencing pain and stress and must therefore be destroyed humanely. There are a few acceptable methods and we will run through them one at a time.
1. Anaesthetic- Immersion in an anaesthetic solution such as Benzocaine or Tricaine Methane-Sulphonate is acceptable and may only be available via your veterinary practice. The effective dose will depend to some extent on the species of fish. An exposure to 300mg per litre of Tricaine Methanesulphonate is sufficient to cause the death to most aquarium fish. It is however advisable to leave the fish in the solution for at least an hour after death to prevent any possible recovery by the fish.
2. Decapitation- In many cases, especially with tropical fish this method is quick, clean and easy.
With the aid of a scalpel, or a sharp knife or even a pair of very sharp scissors this job can be carried out with ease. Lay the fish on a flat surface, prevent it from escaping and with one quick motion, slice its head from its body. The body may still wriggle; this is acceptable, as it is just a nerve reaction. The brain will feel no pain. To prevent HYPOXIA, you must destroy the brain as soon as the fish has been decapitated. Simply simply holding the head and penetrating the brain with a sharp instrument does this. This may sound barbaric, but it is humane.
Concussion- This is a method that is preferred by a lot of aquarist. What you do is wrap the fish’s body in a cloth, leaving the head exposed. Picking the body of the fish you then strike the head off the edge of something hard with a hefty blow. This renders the fish unconscious and then again you must either decapitate it or destroy it’s brain to avoid any chance of recovery. Anglers’ use a club, known as a priest to club big fish such as trout, to render it unconscious. I would not advise that you use such a device with tropical fish.

IBFrog has sent you this email from http://fish.orbust.n...orums/index.php.

You gave several methods in your forum topic. I would like to offer you another given me by my vetrenarian. Emerse the fish in water contaning Alka-seltser. Just keep adding more until the fish sucumms. I had a fish a few years back that managed to rip it's eye badly and was in obvious pain. Since this was not an injury that would heal, we sadly decided to euthanise him. Our vet gave us this method. It worked very well and we did not have to buy anestethic or wack the fish. He quickly calmed and was dead in a few minutes. We left him in the solution for awhile to be sure, them buried him under a rose. (He wasn't sick so no worry of contamination.)

Unacceptable methods of Euthanasia
1. – Flushing a fish down the lavatory
2. – Removing them from the water until death occurs
3. – Plunging them in either boiling or freezing water
4. – Freezing them to death, this method causes pain and immense stress.
– Knocking them unconscious without destroying their brain.

Safe Method of Disposal of the Carcass
You should now exercise some responsibility in the disposal of your fish. Do not throw it in the lavatory as the carcass may contaminate other fish in the waterways. Do not feed the carcass to your other fish or animals, it could spread disease. Remember the reason why you had to destroy it in the first place.
The safest way is to wrap the carcass up in newspaper, place it in a polythene bag, securely seal it and dispose of it in the rubbish.
If you have a real fire, this is another effective method of disposal. Cremation

#2 tttnjfttt


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Posted 04 February 2006 - 06:02 AM

I know I have talked with many people about not freezing fish, and often the question why is asked. Here is some more info on why not to freeze a fish, taken from http://tropicalresou..._guidelines.php

First let me say I used to use the common freezing method too. It's great for the fish keeper. Place the pet in a container shut the freezer door...out of sight, out of mind. Then I asked my vet about it and that was a big mistake. AVMA (American Veterinary Medical Association) says that using the quick freezing method is an unacceptable method of euthanasia. Research shows that during the chilling and freezing process the formation of ice crystals on the skin and in tissues likely causes pain and suffering. The AVMA says that quick freezing can be done if you first render the fish unconscious with another approved method such as clove oil, TMS (Tricaine methane sulfonate) or other means to deeply anesthetize the fish.

#3 steelhealr


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Posted 23 April 2006 - 06:36 PM

Euthanasia is a very controversial topic and I just want to caution everyone who reads this thread on several facts:

1) The best methods of fish euthanasia are listed (veterinary anesthetics) above and are NOT commonly available to the average home aquarist.

2) There are NO sizeable or supportive studies that give strong support to any ONE method of euthanasia outside of the anesthetics available to vets.

3) Two major components of a humane euthanasia are unconsciousness and removal of pain, or, anethesia and analgesia.

4) By last reports, oil of cloves was NOT accepted by the AVMA as a humane method of euthanasia and there are NO studies with regards to fish re: time to onset of unconsciousness

5) Slow freezing and putting a fish in the freezer is NOT humane IMO. I DO take issue with rapid and dramatic deep cold immersion as being acceptable. This is just my opinion extrapolated from medical science.

The bottom line and summary: There is no structured and well designed scientific study that overwhelmingly supports one method of euthanasia over another. Until that time, you must choose your own method for ending the suffering of an animal with dignity. There are multiple methods available to us as home aquarists for which we can 'quickly' end suffering for our aquatic pets. Choose a method that works for YOU if you don't have access to a veterinarian that has the cutting edge anesthetics to euthanize your fish rapidly and effectively.

#4 steelhealr


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Posted 24 April 2006 - 02:51 AM

In order to help those further and try to keep things balanced, here are some rather 'lively' discussions on euthanasia. They are comments by your fellow forum members:

Used Clove Oil for the first time, don't think I did it correctly

How to Euthanize

What is the most humane way to euthanize?

Euthanasia by freezing, is this really the best way?

Methods of euthanasia, are these acceptable?

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