Pet Mice Health Problems – Diseases and Parasites

Although pet mice are known to be very clean animals, they can also get sick. In addition, they can carry diseases that can affect you and your other pets as well. Therefore, it is important to be informed about the most common ailments when it comes to pet mice.

It can be sometimes hard to tell whether your mouse is sick or not. Thankfully, there are always those little signs you should look for in order to find it out. From allergies to deadly tumors, these little animals can be affected by all sorts of ailments.

The good thing is that if you keep the cage clean and feed your mice some healthy food, they are probably not going to get sick. It is also important to keep them hydrated, to keep them in a stress-free environment and to make sure they have enough toys for exercise.

Since you are interacting with your pets on a regular basis, you should wash your hands before and after touching your mice or anything in the cage. This way, you can reduce the possibility of them getting sick even more.

Most Common Pet Mice Diseases and Illnesses

There are some common ailments you should look out for as a pet mouse owner. Below, we are going to talk about a number of illnesses and other health issues that can affect your little pet. By the end of the article, you are going to know exactly how to spot them, the symptoms that arise and how dangerous they are.

We are also going to inform you about what needs to be done in order to prevent and treat these ailments. Without further ado, let’s get into it.

– Stress

Stress can cause many health issues in mice. First off, be careful when putting your mice in a new environment. If you put a mouse into a new cage with unfamiliar mice, there is a chance that he will get stressed out. The same can happen if your mice have nowhere to hide or are constantly exposed to bright light.

As a result, your mice will start to gnaw their own fur and become balder and balder over time. Stress can also cause Sticky Eye, which is a common eye problem. As a result, a discharge will come out through the eyes which is called stress fluid.

In this case, all you need to do is to keep their eyes clean and it will disappear in a few days. If it gets worse, then make sure to contact the vet. Mice can get stressed in many ways. It is important to put them in a big enough cage and to be patient until they get used to you.

You don’t want your mouse to be afraid all the time. This is also why you should keep the cage away from cats and other pets that would go near it.

– Injuries

Your pet mice can get hurt in many different ways. Being dropped by accident, injured while playing or while fighting with each other all falls into this category. Also, many owners don’t know how to handle their mouse pet. You can’t pick him up by his tail for example because that can cause injury.

The most common cause of injury is definitely when two males fight with each other. Once you notice this, make sure to separate them because they are eventually going to fight to death. When it comes to the cage, try to avoid using toys or accessories where their legs, tails or necks can get stuck.

Avoid putting your mice on top of tall shelves, furniture or even on your shoulder. If that little guy falls off, he can really hurt himself. Also, don’t pull mice away when they are grabbing or biting something. In most cases, they are not going to let go and it is going to be extremely painful for them.

– Allergies

Just as us humans can become allergic to a lot of things pet mice are really no different. The main cause of allergies in mice are bad-quality beddings. There are shavings that are recommended and others that are absolutely not. Look for wood shavings that are completely dust-free.

Sawdust is definitely something to be avoided when it comes to mouse bedding. Certain materials contain toxic phenols that can cause serious health problems to your mouse. These are cedar or pine for example.

It might be tempting to buy shavings that are scented. Obviously, you want your room to be free of bad smells and that is one way to achieve that. The bad thing about them is that they are not healthy at all and will eventually cause allergic reactions.

In case you are looking for hay, make sure to put it into the freezer after buying it. In pet shops, you can even find vacuum-packed hay in various brands. We recommend you to look for a high-quality pack and buy that one.

The same applies to foods and cleaning fluids. After cleaning, you need to properly rinse out everything before putting it back to the cage. And the food you buy or prepare shouldn’t contain anything that might cause allergic reactions.

Other things that can cause allergies are scented candles and seasonal pollens in the air. If you notice that your mice have watery eyes, discharge in the ears or nose, inflamed skin, breathing problems or greasy fur, then they are probably allergic. Change in their behavior such as excessive scratching, sneezing, itchy ears or coughing also indicates the same.

– Skin Problems

If you find a lump on the skin of your little mouse, then it is not necessarily a tumor. Abscesses are, in fact, quite common in these rodents. This is a skin problem that is most likely caused by a bite. Therefore, it can happen in case there is more than one mouse in the cage.

Female mice don’t fight with each other, although males definitely do. If they bite each other, then it can quickly turn into an abscess. The bite will become a swollen ball and if you touch it, you can even feel that there is a root under it.

An abscess can also appear as a leaking wound or a squashy area on the skin. Mice react to it by biting at it, rubbing it or cleaning the area. This, of course, causes great discomfort for them. The problem can be solved often just by draining the pus out of the wound.

If that doesn’t work, then contact the veterinarian and he will give you some antibiotics that work. An abscess, however, doesn’t always mean that there is an open wound.

– Respiratory Problems

Your mouse can easily get an upper respiratory infection if he is living in a dusty or straight up dirty cage. You can also look this up by searching the URI abbreviation. This doesn’t depend or gender or age. However, it is certainly more likely to affect older mice since they have weaker immune systems.

Forgetting to clean the mouse cage every now and then is not a big deal. Although if you ignore it for a long period of time, then your mice are not going to feel well. Symptoms you are going to notice are watery or sealed eyes, wet nose and ears, unusual noises, coughing, having a hard time breathing and ruffed coat.

When you notice these symptoms, it is not going to be enough to just clean up the cage. We recommend you to call the veterinarian and he will probably give you some antibiotics. If your pet mouse is suffering from respiratory problems, it can quickly become fatal.

In order to prevent this from happening, make sure to clean the cage at least once a week. Also, don’t use scented or sawdust shavings.

– Cancerous Tumors

After reaching the 1-year-old mark, the chances of developing a tumor increases in mice. Although other rodents have a higher chance to develop benign tumors, this is definitely not true for mice. Their tumors are usually malignant and can become very dangerous after 2-3 weeks.

These can manifest themselves in many different ways. If you notice a lump over the skin with no root attached to it, then there might be a serious problem. Other symptoms are swollen belly, blood from the genital area, sudden weight loss, walking problems, lethargy or unusual posture.

If you notice it in time, the tumor can be removed by low-risk surgery. The worst thing about them is that they usually reappear within a couple of months. After surgery, the best thing you can do is to check your mouse every day. If there are no symptoms after 3 months, then the tumor is not going to return.

In case you have an older mouse, the likelihood of removing the tumor is going to be very slim. Finding a lump doesn’t necessarily mean that it’s a tumor. It can also be a simple injury, a cyst or an abscess. Mice have the tendency to develop mammary tumors and other types are rather uncommon.

– Parasites (Fleas, Ticks, Mites, Pinworms)

If there are other pets in the house than mice, then you should be aware of these problems as well. There are many animals that can bring mites, fleas and ticks in the house and spread them around. Since these live on the skin and below the fur, they can be extremely unpleasant for the animal.

Various skin infections can develop while your mouse is constantly scratching and even balding in the process. They cause your pet to be constantly annoyed by these little parasites. The symptoms are easily noticeable. Your mouse will slowly go bald, revealing the skin that is usually scaly with black spots or bugs on it.

It involves constant physical discomfort followed by obvious ticks that indicate the problem. The good thing is that in most cases, your mice are going to have mites which are easy to get rid of. The best idea is to call the vet who will inform you about the treatment. Mites are caused by low-quality bedding.

If you are not sure whether the shavings you bought are high-quality, then just freeze the package for 24 hours. Pinworms develop when your mouse eats their eggs. They grow to full size in the large intestine. There are various medications available against pinworms that will easily solve the problem.

Besides that, you should pay more attention on keeping the cage clean in the future.

– Wet Tail Disease

Although this ailment is common among rodents in general, it is definitely not as common in mice. However, there is still a slim chance that your mouse can be affected by it. The main cause of wet tail is that your mouse is suffering from urinating problems.

This urine leakage can potentially kill your mouse if not treated in time. Wet tail can manifest itself in many ways. If your mouse feels stressed all day, has a weird toilet routine and looks confused while urinating, then there might be a problem.

Other things that can indicate the ailment are shaking, wetness around genitals and a complete lack of appetite.

– Infections

If your mouse is old, then there is a chance that he can get a Urinary Tract Infection. This is even more common in females. If not treated in time, then it can become very serious. This infection is caused by the spread of bacteria inside the bladder that eventually enter the urethra.

You can easily prevent this from happening just by keeping the cage clean. The symptoms are quite recognizable. Smelly or even bloody urine, painful urination, thirstiness and being wet with brown or yellow urine. The worst thing about it is that it can spread to the kidneys so it’s important to treat it with antibiotics as soon as possible.

If your mouse is lucky, then this can be cured in a few days.

– Eye Problems (Sticky Eye or Blindness)

The two main causes of sticky eye are allergies and stress. If you notice some red discharge in the eye of your pet mouse, then it’s most likely not blood. Your pet probably has sticky eye and that type of discharge is the result of this ailment.

It is a type of stress fluid that leaves the body through the eyes. Sticky eye can develop when your mouse goes through a stressful period of time. You can expect this to happen if you move your mouse to a new home, for example.

You can gently clean your pet’s eyes by bathing it in water. This often resolves the problem. If it gets worse, however, then you should definitely call the vet. If you notice white lumps or swelling in the eye of your pet, then it might be a sign of severe infection.

This might even cause him to eventually go blind. The best thing you can do is to keep the cage and your hand as clean as possible. If it doesn’t get better, then you need to take your mouse to the vet. Discharge in the eye can appear in a wide range of colors.

If you notice that his eye is more watery than usual, then it usually indicates that your mouse is tired.

Can You Get Sick from a Pet Mouse?

Although pet mice and other rodents can look nice and healthy, they, in fact, can make their owners sick. The germs they can carry can be dangerous to us humans too. The good thing is that you won’t get sick if you follow a few safety measures.

If there are kids in the house that are less than 5 years old or a pregnant woman, then you shouldn’t buy a mouse. It is not recommended for people with a weak immune system either. After touching your mouse or anything around it, don’t forget to wash your hands.

You can play with your mouse outside the cage, just wipe up all the surfaces afterward. Keeping your mouse near the kitchen is also not a good idea. Pretty much everything in your mouse’s cage has to be cleaned and disinfected on a regular basis.

Keep in mind that some of the gems they carry can cause serious, in some cases even life-threatening illnesses to us.

Can Your Dog or Cat Get Sick from Your Pet Mouse?

They certainly can. For example, there is the bacterial disease called Leptospirosis that can affect not only a big number of animal species but humans as well. The bacteria get out with the urine. Animals or humans then can get infected directly or indirectly with this urine through water or soil that is contaminated with it.

Rodents can also carry salmonella which gets into their system by eating or drinking anything that contains the bacteria. This infection affects the intestines and it can cause serious disease. In case your cat or dog eats a mouse that has Toxoplasmosis cysts. This is more dangerous for dogs, but it can cause serious symptoms in cats with weakened immune system as well.

For dogs, it can cause diseases in the nervous system, in the liver and it can also cause pneumonia and diarrhea. Cats can spread Toxoplasmosis further through their feces. Besides Toxoplasmosis, mice can infect your dog or cat with Roundworms too. These then grow in their intestines and eat most of the nutrition they can find there.


Hopefully, with the help of our article, you can identify the health problems of your mice in time. But let’s be optimists and hope that your little pets are not going to face any of these ailments. With proper care and comfort, chances are that they are going to live a happy and healthy life.

No matter which of these problems are your pets going to be affected by, the best idea is always to call the veterinarian and ask for help. The vet will either inform you that there is nothing to worry about or tell you exactly what you need to do in order to cure the particular ailment.

You should take action while the early signs are there. This is how you can guarantee full recovery for your mice. The more you wait, the more serious the problem can become.

avatar Jane
Jane is an experienced animal care specialist with a focus on rodents and small mammals, with over 10 years of experience in the pet industry. Her articles provide practical guidance on choosing the right pet and managing common health issues. Jane is an advocate for animal welfare and supports organizations dedicated to protecting wildlife. read more...

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