Mice are resilient animals and rarely get sick. Furnishing appropriate housing, a nutritious diet, good hygiene, and considerate care will minimize disease. Signs of illness in mice include a ruffled coat, depressed attitude, lethargy, closed or squinted eyes, reluctance to move even when handled, and a loss of appetite. Changes in the color, consistency, smell, or amount of urine or feces may also indicate that your mouse is sick. Any of these signs are a good indication that your mouse needs to see a veterinarian immediately.

Checking for Signs of Illness in Mice
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.

Respiratory infections are common in mice, so they should be kept away from damp and drafts. Reducing dust from shavings and keeping the cage environment clean may help minimize the frequency of these infections.

Dental Care

The incisor teeth of mice grow constantly and must be worn down by gnawing. Mice should be provided with appropriate materials, such as wooden gnawing blocks, to satisfy their need to gnaw. In addition, periodic trimming with nail clippers or a dental bur will prevent the teeth from growing too long. Overgrown incisors can lead to difficulty with eating, weight loss, dehydration, and oral trauma.

Last full review/revision July 2011 by Katherine E. Quesenberry, DVM, MPH, DABVP (Avian); Kenneth R. Boschert, DVM, DACLAM