Look for general signs of illness, such as poor appetite, hunched posture, listlessness, and matted or puffed-up fur.
Learn to spot signs of respiratory infections by listening for abnormal breathing or chattering and checking for any discharge from the eyes or nose. A mouse with a respiratory infection should be seen by a veterinarian.
Check the teeth and gums for any misalignment or overgrowth of teeth, gum swelling, redness, pus, or foul odor. Oral infections can progress quickly and need early medical intervention to be resolved.
Check the mouse’s ears for discharge.
Visually inspect your mouse’s body for bleeding, wounds, or injuries.
Look for signs of trauma such as limping, tilting, or circling when walking.
Check for lumps, swelling, or areas of sensitivity that might indicate pain.
Check the fur around the mouse’s shoulders and neck for any scabs that might indicate parasites. Also watch your mouse’s behavior to see if it is scratching excessively.