Updated 7.10.2020

MOUSE / RATEUTHANASIA

INSTRUCTIONSFor more detailed step-by-step instructions, please refer to the

Guidelines for Rats & Mice Euthanasia Procedures for Investigative Personnel(az.research.umich.edu/node/1016)

In-House CO2 Setup

https://animalcare.umich.edu/https://az.research.umich.edu/node/1016

7.10.

2020

REMEMBER, IF CONSOLIDATING ANIMALS FOR EUTHANASIA:

No more than 10 mice in a standard mouse (#1) cageor 25 mice in a large mouse / small rat (#3) cage

Follow standard housing densities when consolidatingother rodents (e.g. rats) for euthanasia

Provide ample space for animals to move and assumenormal postures if using your own euthanizing chamber

Start the procedure no more than 10 minutesafter the animals have been consolidated

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01STEP7.10.20

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The flow meter (1) should be at zero

The supply valve (2) and flow meter (3)should be turned o� (all the way clockwise)

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02STEP

Insert the CO2 hose through thewater bottle grommet on the cage lid

ORthrough the lixithole

in the back of the cage

MOUSE – SMALL RAT CAGE

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03STEP

Turn supply valve (1) to the leftor counterclockwise to turn on the CO2

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04STEP

Until the gauge (floating black ball)(2) reaches the desired color line

Adjust CO2 flow into the cageby turning regulator knob (1) slowly

BLACK is for RAT #3 cages

GREEN is forLARGE MOUSE #3 cages

BLUE is forSMALL MOUSE #1 cages

INSET

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05STEP

Allow gas to flow until animalsare no longer moving or breathing

You MUST remain with your animals untildeath is confirmed by a secondary means

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06STEP

Note that gauge (2)is falling back to zero now

Turn o� the CO2 supply valve (1)

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07STEP

Gauge should now be set at zerowith no more CO2 flowing

After gauges reach zero, ensure flow meter valve (1) is shut o� by turning it clockwise until snug

Do NOT overtighten

INSET

seepicture inset

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08STEP

Check your protocol for approvedsecondary euthanasia method

ALWAYS perform a secondary, physical method to ensure euthanasia is e�ective

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09STEP

After you have confirmed deathby a secondary, physical means

Put carcass in a glove or opaque bag

Label with PI name, date, and nameof individual conducting euthanasia

DATE:

PI NAME:

INDIVIDUAL:or

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Place in appropriate binwithin carcass cooler

10STEP

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We want to acknowledge that the ethical cost of using animals in researchmay cause some individuals emotional distress, especially if they perform euthanasia

as part of their occupational/research duties.

If you think you may be struggling with what is commonly referred to as“compassion fatigue,” there are resources that can help.

Visit animalcare.umich.edu/cap or email CompassionFatigue@umich.eduto learn more about our Compassion Awareness Project.

QUESTIONS?Contact your ULAM Faculty Veterinarian and/or

your facility’s ULAM Husbandry Supervisor

Bookmark and review therodent euthanasia guidelines on Animal Care A-Z

(az.research.umich.edu/node/1016)

https://animalcare.umich.edu/https://az.research.umich.edu/node/1016mailto:CompassionFatigue@umich.eduhttps://animalcare.umich.edu/cap