What the most humane way to euthanize a fish? (1 Viewer)

[Ryan Tsang]

I have a sick fish that's not gonna make it. I was thinking of putting him in some cold water and put him in the freezer. Would his vitals just quietly shut down thus painlessly go?

 

[Yousaf]

Well, considering that the most humane way to euthanize a human is with chemicals, maybe you could just put him in a disposable bowl with some draino or antifreeze in it.

 

[Philip_G]

put him in a plastic cup of tank water and put it in the freezer, they just "slow down" as the water gets colder until everything stops.
Could go the opposite way and plunk him in boiling water too, the shock would probably kill him instantly.

 

[Mark Hayenga]

Freezing is good. But don't use cold water to start out with, just use normal tank water. Let him cool down slowly, it will prevent thermal shock. They're ectotherms so his metabolism will just slow down to a crawl, and then he'll die.

 

[Brian Johnson]

I'm new to the fish tank hobby & now have a thriving 30 gallon setup.
In my months prior to setting up I've read everything I could online regarding the hobby & this has came up.
While it may sound brutal, I've read that simply cutting off his head is the quickest/painless way to kill a fish. Instant death.
You don't want anything that will lengthen the fishes suffering like freezing him.
They also say flushing is NOT the way to go. Imagine spending the last moments of your life swimming in crap & goo. I guess if the fish is already dead it doesn't matter.

 

[Cees Alons]

Freezing (or boiling) seems too cruel.

The quickest and least painful, and therefore most humane, way would be what Brian says, but difficult for you to do perhaps: take him out and quickly cut (hack) off his head with a sharp meat knife. He/she wouldn't feel a thing.

I know someone who dropped a sick fish in a liquid Nitrogen bin at the lab were he was working. But freezing it in your refrigerator would be ... slow.


Cees

 

[Chris]

Slow, and not very humane. You're right, a quick use of a knife is the least pain, but probably hard to do. If you have some Gravol type solution (Hydroxyzine is a good one), it's a liquid nervous system inhibitor, designed for sleep in humans. But it will ahem, kill animals. But, because it's a nervous system inhibitor, they wouldn't feel it.

 

[Cees Alons]

One thing more.
Is he/she really in pain? If not, you could postpone (avoid) that quick blow and wait. Often those animals die gracefully, without much suffering.


Cees

 

[Jason Adams]

I was going to suggest to put him in a bowl of water with ammonia in it, which would oxidise the gills, but I suppose that wouldn't be humane.

 

[charlie o]

all drains lead to the ocean.

 

[Foster]

Keep in mind that tropical fish, like humans experience shock. That's why great care is taken when moving them from one tank to another. This gives them time to acclimate to the newer temp of their future home. A variance of just a few degrees can be enough to kill them, and of course while in shock they feel nothing.

Colder seems more humane, but I've killed (unintentionally) dozens when I used to leave a tank heater on while I was away for a week or longer. I was teen then and didn't know any better.

The thermostat inside the heater would get stuck on, and the whole colony would perish. Actual water temp wasn't that hot, maybe 85 or 90 instead of the usual 74-76. Not boiling, but it was enough. :frowning:

 

[Chris Farmer]

I don't want to sound like a harsh person here, but actually with a fish, it's not something that needs to be worried about as much. Fish, unlike birds and mammals, lack the receptors and nerves to experience the signals we interpret to be pain. They are physiologically incapable therefore of feeling any sort of pain whatsoever.

 

[Tony Whalen]

As someone who has been into aquariums for some time now, I must agree with Brian and Cees. It's the quickest way. Not fun for the aquarist, but from my studies, it's the best way to go.

 

[Peter Burtch]

Not quite. With freshwater fish a few degree sudden change will NOT kill them outright. But some species are more likely to become sick (and later on die) if they are not kept in stable water temperatures. Saltwater animals are much more succeptible to shock/death from such sudden changes in temperature than their freshwater cousins.

It really does suck to have heater stick and practically boil a whole tank of your pets ;(. Typically the increase to 85-90F isn't what kills then, but the lack of oxygen in the tank if the bioload is great and the temperature stays so high. Water holds more oxygen at the lower (normal) temperatures.

-Pedro

 

[Bry_DD]

Just wait till he or she drop dead. and if you can't wait just flush it in the toilet bowl.

 

[Philip_T]

So what did you end up doing? Curious minds.....and all that. Did he get better by chance??

 

[Bry_DD]

Just wait till he or she drop dead. and if you can't wait just flush it in the toilet bowl.

 

[Ryan Tsang]

Well...I ended up freezing it. It was on its side and breathing very slowly. It got beat up by a larger fish and the body on both sides developed massive cotton wool infections (likely fungal) and you could see specks of flesh underneath. When it swam quickly, some of the cotton wool would flake off...sick.

It was a 4" Green Severum and I thought there would be too much body mass to cut thru. If it was a guppy, I'd chop it.

I gave away the big fish (and his girlfriend) and I'm gonna start new. I'm ok. Thanks for the responses.

 

[Peter Burtch]

Sorry you had to go through that, Ryan ;(.

Before you start again, I hope you don't mind if I ask what size tank you have and what filtration you are using(?) Severums can get pretty large.

-Pedro

 

[Frank Grimes]

Shake N' Bake