Why is age verification important before performing procedures on a mouse?

• A. Because younger mice are more colorful.
• B. Because age does not matter.
• C. Because age can influence physiology and anesthesia risk.
• D. Because older mice breed faster.

Answer: (C)

Age affects how a mouse’s body handles anesthesia, surgery, and recovery. As mice mature, their organ systems develop and enzyme activity changes, altering how drugs are absorbed, distributed, metabolized, and eliminated. Younger mice often have developing liver and kidney function, different body water and fat distribution, and a higher risk of hypothermia and respiratory depression under anesthesia. Older mice may have reduced cardiac and hepatic function, slower drug clearance, and slower healing, which all change procedure safety and recovery. Because of these age-related differences, confirming the animal’s age helps choose appropriate anesthetic dosing, monitoring, and post-procedure care to minimize risk.

Other options miss the essential point—that physiology and anesthesia risk change with age.