How to Identify the Cause of Sneezing in Pet Mice
If your mouse is sneezing more than usual and you want to identify the cause, look for additional symptoms like a runny nose, which might point to a respiratory infection. You should also hold your mouse close to your ear and listen closely for labored breathing, a sign that it has a lung infection. If your mouse is also lethargic or has no appetite, consider taking it to a veterinarian to see if there is a larger problem. A vet will be able to diagnose the problem and help you give it any antibiotics.
Look for signs of congestion. Additional symptoms can give you clue to the cause of your mouse's symptoms. For example, if your mouse has signs of congestion, such as a runny nose, then the sneezing could be related to a respiratory infection. Look for dampness under your mouse's nose. This may signal a runny nose. Assess your mouse's breathing. Labored breathing can signal that your mouse is fighting off a respiratory infection. If you hold your mouse close to your ear, can you hear labored breathing? This is a sign that there may be an infection in your mouse's lungs. Depending on the mouse, you may not be able to get close enough to it to assess its breathing. If this is the case, look for other symptoms to help you assess your mouse's health. Look for a loss of appetite or lethargy. Loss of appetite or lethargy can signal that your is fighting off illness. While no appetite and inactivity can signal a variety of problems, combining it with sneezing signals that your mouse may have a respiratory illness. Loss of appetite and lethargy can also signal a variety of other illnesses. If your pet mouse is inactive and is not eating, you should get it checked out by a veterinarian. Eliminate possible allergens. If your mouse doesn't have any other symptoms of a respiratory infection, then explore other possible causes for the sneezing. In order to narrow down the cause of your mouse's sneezing, you will want to remove any possible allergens from your mouse's cage. In most cases of an allergic reaction, the cause is the mouse's bedding. Clean out your mouse's entire cage and replace the bedding with paper-based bedding that is dust free, which can simply be a layer of shredded paper. If your mouse was indeed allergic to its bedding, its sneezing should stop in a week or two. Wood bedding is usually the cause of an allergy. If you find that your mouse is allergic to wood bedding, don't use it anymore and find a suitable replacement. Take your pet to a veterinarian. If your mouse is sneezing a lot, and eliminating allergens did not eliminate its sneezing, then you should take it to a veterinarian to be assessed. A veterinarian that is experienced with mice will be able to assess your mouse's symptoms and can likely give you a diagnosis. Find a veterinarian that specializes in small animals. It can be hard to find a veterinarian for a pet mouse. Call the veterinarians in your area and ask if they are comfortable treating a mouse. Even if they do not treat mice, they may have a suggestion about a veterinarian in your area that will. Give your mouse antibiotics. If your veterinarian suspects that your mouse has a respiratory infection, he or she will likely prescribe it antibiotics. This medication will help the animal fight off the infection. Follow your veterinarian's suggestions for dosing and for how long to continue giving the medication. Some respiratory infections cannot be eliminated by antibiotics, such as some mycoplasma infections. However, giving a pet mouse antibiotics even with this type of infection will support its immune system in keeping the disease controlled. Keep your mouse's cage clean. Cleaning your mouse's environment clean will help if fight off any infection it has. If the mouse does not have to fight off any other bacteria or virus, which fester in dirty cages, then it can more easily recover from its illness. Clean your mouse's cage on a regular basis, whether it is sick or not. This will help its overall health and happiness. 
Look for signs of congestion. Assess your mouse's breathing. Look for a loss of appetite or lethargy. Eliminate possible allergens. Take your pet to a veterinarian. Give your mouse antibiotics. Keep your mouse's cage clean. 