As an aside, there must have to be a relief vent, otherwise the introduced gasses wouldnt be able to replace the oxygen, and the pressure in the chamber would increase, i had this thought after. I figure it must be towards the top, as the carbon dioxide is heavier than air, and will fill the bottom
Tube with the end in a cup of water should suffice.
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Our set up in the lab is simple and practical. CO2 tank with a regulator and piping attached to a steel lid the exact dimensions of the home cages (with extra lip to prevent out flow). The lid has 2 exhaust holes allowing oxygen to be displaced.
When euthinasia is required, the steel lid is placed over the home cage, and the CO2 is pumped for about 10 minutes. An extra 15 minutes in the cage after the CO2 is off ensures there is no sudden recovery via the introduction of new oxygen (which would likely cause the animal extreme stress and suffering).
A cage was shown for example, these rats were not euthinized today, and as a note we generally only keep 2 rats to a home cage, but this litter had an extra small female so there are 3 so that no one is lonely.
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Thanks for the info! Looks like its fairly straight forward!
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Happy to help! Also worth it for the bewilderment on my professor’s face when I explained why I wanted a tour of the CO2 overload process, ha!
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Use foam weatherstripping as a seal on the rim of the tub if you’re using standard plastic tubs, and not rigid polycarbonate tubs like the lab grade tubs.
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My recommendation as well. Also depending on the size of the rodent you are using, more space per animal would likely help reduce stress, but again, lab-grade isn’t the same as pet- or feeder-grade
I finally got an acceptable (to me) CO2 chamber =D.
Now, I know what you are thinking: “Verinium its been so long since you started looking, how were you culling your rats?”
Excellent question! I uh… havent been… theres so many xD. A trip to airgas and i can finally get this food production plan spinning into action!
(Placement of CO2 chamber was just where i hooked it up to test it, not its permanent location.)
There were 2 of these each for about 700$ and im pretty sure they are well over 2k normally… was tempted to get the second as a backup in case it fails and i get stuck on another 7 month search … may still do it. But id rather ensure nothing is wrong with this one once i get it hooked up to gas. Without gas, everything else runs properly.
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Im glad i went through the time and effort. This is by far my least favorite part of this whole snake breeding thing. Give me vet bills, electricity costs, etc. This right here kills me, and if i had to so it like 2 at a time, it would be far worse on my concience. At least this way the whole tub can be done together, so its not like they notice their numbers are slowly going down. Pic is before cas or anything was started, as im sure people dont want to see during the process.
Just a for scale picture.
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I use a weathersealed bin. Drilled one hole in the side and one in the lid. Placed gaskets in the holes and run a tube from the co2 tank to the tub to a bottle filled with water. Havent had any issues and they are not suffering. Been using this setup for over two years now.
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Yeah, im just not handicapable, and i didnt trust my terrible craftsmanship to humanely give the animals a good death. With the setup i bought, i can do a whole colony at a time, and all i have to do is push a button and come back 15 minutes later… well that and live with the guilt xD. Im sure the second part gets better with time, but for now, it hurts. It hurts less knowing i have done everything in my power to ensure their deaths are humane and painless.
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