Originally Posted by Emmnemms
I haven't had to euthonize any bettas, but i did work for a year in the watershed out here. We handled Salmon/trout Frys and smolts.
As it was said, you shouldn't touch the slimy part of the fish unless nec. since the slime protects against infection, and once the slime is gone, there is almost no protection if they get cuts...
But we did have to knock the fish unconscience to take their weight and size. We did this by putting alkaseltzer in the water, which took out the oxygen in the water... but i guess since they breathe air like we do this won't work...
I read in a betta book the best way to euthonize a fish is to place it in boiling water... i don't think i could do this. and i suspect there is a much better way to do it...
but i really hope he gets better first!
After reading the above I felt like I needed to post this (copied from a post on our forum):
Most Humane Methods:
MS-222: This is really the only method approved by the American Veterinary Medical Association (AVMA) as humane that is available to the home hobbyist. It is commonly used as an anesthetic on fish and so the fish will become sedated and free of any pain when using this method. This substance comes in a power that you should mix with a bit of water before using. Place the fish in a small container and slowly add the MS-222 solution while watching for slowing gill movement. Once gill movement has completely ceased for 60 seconds the fish is no longer alive. Finquel is one brand commonly found in the US, but will probably need to be purchased online.
Clove Oil: Similar effects to MS-222 but it can be purchased over the counter at most pharmacies and health stores. It can be added directly to the water with no preparation before hand, however, it is not completely water-soluble so it is best to mix with a bit of ethanol (grain alcohol such as vodka) before using. The process is the same as with MS-222.
Ethanol: This is a grain alcohol, as pure as possible, such as vodka or tequila. The alcohol should be completely clear and as high a proof as you can acquire. This works similarly to the two methods above.
Other Conditionally Acceptable Methods:
Blunt Force Trauma: This method is not as humane as the ones listed above as the time spent lying out of water is stressful. It also introduces problems such as the aim of the person performing it. I would only recommend it for fishes which are too large to be accommodated in another way. Wrap the fish in a damp paper towel and use a large, heavy object such as a brick. Best if the fish is first sedated.
Temperature Shock: A container of water is placed in the freezer (without the fish!) and allowed to become as close to freezing as possible. Then break the surface, which should be frozen, and place the fish in the water. When performed properly it will instantly shock the fish’s nervous system and stop all organ function. Best if the fish is first sedated. NOTE- this is not an acceptable method for coldwater fish
Decapitation: Studies show that nerves will still fire for approximately 10 seconds after the brain is severed
Freezing (this is different from temperature shock as the water has not been pre-chilled)
Alka-Seltzer- effectively suffocates the fish by releasing CO2. The AVMA lists CO2 as acceptable for terrestrial animals, but it should not be confused with aquatic animals.