Assistant Laboratory Animal Technician (ALAT) Practice Exam

Which type of animals are known to be resistant to CO2 as a euthanasia method?

1. Adult rodents

2. Neonatal rodents

3. Felines

4. Canines

The correct answer is: Neonatal rodents

Neonatal rodents are known to exhibit a degree of resistance to carbon dioxide (CO2) as a euthanasia method. This resistance is largely due to their physiological and neurological immaturity, which can affect their response to high concentrations of CO2. Unlike adult rodents, which are more susceptible to the effects of CO2 euthanasia, neonatal rodents may tolerate it longer. The developmental stage of neonatal rodents means their respiratory systems and other biological functions are not fully developed, making them less sensitive to changes in environmental gases compared to adults. This understanding is crucial in laboratory settings, as it underscores the need for age-appropriate euthanasia methods to ensure humane treatment of all animals used in research. In contrast, adults and other species like felines and canines generally respond more predictably to CO2 and other euthanasia methods, making these methods effective for those populations but not for neonatal rodents.