Euthanasia Guidelines

CRITERIA FOR EUTHANASIA
Euthanasia of animals is expected if animals demonstrate the conditions listed below. Fulfilment of one criterion can constitute grounds for euthanasia.

1. Weight loss: loss of 20-25% (depending on attitude, weight recorded at time of arrival, and age: growing animals may not lose weight, but may not gain normally) or if not measured, characterized by cachexia and muscle wasting.

2. Inappetance: complete anorexia for 24 hours in small rodents, up to 5 days in large animals; partial anorexia (less than 50% of caloric requirement) for 3 days in small rodents, 7 days in large animals.

3. Weakness/inability to obtain feed or water: Inability or extremereluctance to stand which persists for 24 hours, assuming that the animal has recovered from anaesthesia.

4. Moribund state: depression coupled with body temperature below 99 F, or non-responsive to stimulation, assuming that the animal has recovered from anaesthesia.

5. Infection: infection involving any organ system that fails to respond to antibiotic therapy within an appropriate time and is accompanied by systemic signs of illness.

6. Signs of severe organ system dysfunction non-responsive to treatment, or with a poor prognosis as determined by a veterinarian:
Respiratory: dyspnoea, cyanosis.
Cardiovascular: blood loss or anaemia resulting in hematocrit below 20%; one transfusion may be performed.
Gastrointestinal: severe vomiting or diarrhoea, obstruction, intussuception; peritonitis, evisceration (immediate euthanasia required).
Urogenital: renal failure characterized by elevated BUN, creatinine or uroperitoneum.
Nervous: CNS depression, seizures, paralysis of one or more extremities; pain unresponsive to analgesic therapy.
Musculo-skeletal: muscle damage, bone injury, locomotor deficits, etc. resulting in inability to use the limb.
Integumentary: Non-healing wounds, repeated self-trauma, second or third degree burns.

Chloroform is not acceptable for either anaesthesia or euthanasia as it is very toxic to many species of mice. Additionally, this compound has been shown to be carcinogenic.

Ether is irritating, flammable and explosive, and should not be used in animal rooms.

Chloral hydrate and alpha chloralose used as sole agents are not adequate to reliably achieve euthanasia

Always UNACCEPTABLE in awake animals: KCl, MgSO4, strychnine, neuromuscular blocking agents, exsanguination, air embolism, freezing and chloroform (due to its hazards to personnel).

USE OF THE CO2 CHAMBER FOR EUTHANASIA OF RODENTS

I would remind you that the directions below are for use in a laboratory by trained staff only.

DIRECTIONS
1. Before putting animal in, pre charge chamber with CO2 for 30 seconds.
2. Place animal, or cage with animal, in chamber and close lid.
3 . Wait approximately 3 minutes for animal to stop moving or breathing. Eyes should be fixed and dilated.

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