Common Mice Health Problems

Common Mice Health Problems

Health & Safety

Mice are generally healthy animals and most owners never come across any health problems. However, if you notice a change in the behaviour of your mice like not sleeping as much; excessive itching, not eating normally, being anti-social or anything out of the ordinary there might be an underlining health issue.

Some of the possible health problems pet mice can be affected by are detailed below:


These little parasites live on the surface of the skin on rodents. They spread by passing directly between invested mice and new hosts, it can be hard to diagnose as they are not visible to the naked eye. They do not suck blood like lice do, instead they feed on dead skin cells primarily around the face and neck of a mouse. They do irritate the mice however, causing excessive itching resulting in broken skin and scabs.

There are sprays and direct application treatments to kill mites, a complete clean of the cage and accessories inside will be needed to kill all un-hatched eggs too.


Lice will make their home within the fur on your mice and suck their blood. Signs that your mice have lice include excessive itching, restlessness, lack of sleeping and weakness. It is not too hard to diagnose the problem as a lice infestation as you can see the eggs, or adult lice attached to the mice when looking carefully.


If your mouse starts sneezing it may just be a reaction to the bedding or something else in their cage. Mice are sensitive to some materials such as cedar or pine and will have an allergic reaction.

It is also possible for mice to catch a cold, this will result in lethargic behaviour and sneezing. If you suspect this to be the case you should keep a close eye on them for a few days, if your mouse does not improve then veterinary intervention will probably be necessary.


Unfortunately mice are susceptible to forming tumours. If you discover a lump or an unusual growth on your mice while handling them you should consult your veterinarian as soon as possible. Once a tumour has started to form it will grow larger over time and may cause other problems. They can often be removed if caught early enough.


We have a responsibility as pet owners not to get carried away with feeding too many treats to our pets. I know how tempting it can be, mice always seem so grateful and happy when taking nuts or chocolate drops out of our hands. But it is not healthy for them, and certainly not what they would be eating in volume out in the wild.

If your mice become obese through overeating they will start to develop health conditions such as heart disease and breathing complications.

Teeth Problems

Much like rats, mice have teeth that continue to grow throughout their lives. These teeth may require the intervention of a veterinary professional to trim them, but in most cases the mice will wear their teeth down naturally.

It becomes fairly obvious when mice are experiencing problems with overgrown teeth as you will see them sticking out of their mouths. Overgrown teeth will make eating more difficult, they may get caught on cage bars or other items and can grow into the roof of the mouth causing severe discomfort.


Symptoms of pneumonia are sneezing, sniffing, inflamed eyes and compromised breathing. If caught early a course of antibiotics will be able to clear the infection. Depending on advice from your veterinarian you will need to either add the antibiotics to the drinking water, or inject it directly into the infected mouse.


Mousepox is a virally transmitted disease capable of infecting a large group of mice in a short amount of time. When infected a mouse will start to become lethargic, develop swelling around the face, and have uneven fur and diarrhoea eventually leading to death.

There is no cure once the mouse in infected, there are some preventative treatments however and you can help control some of the symptoms. Veterinary advice will be required.


A common problem with mice is pinworms. Pinworms are intestinal parasites that are passed among mice through contaminated food. It is not always easy to diagnose as mice will not always show obvious signs that they are infected. The infected mice will usually have prolonged bouts of diarrhoea and may be losing weight.

Pinworm is diagnosed by having a sample of faeces tested, if infected there will be worms or eggs present. Your veterinarian will advise you of the best treatment and how to sanitise your cage properly so they don’t return.

Barbering (Self-biting fur)

Sometimes mice will bite and pull out the fur of other mice within their group, or even their own fur occasionally. This is usually a result of bully tactics by the dominant male of the group, or because of stress, boredom and overcrowding.

The skin is usually unharmed and there will be no blood drawn, you may see signs of irritation if the affected mouse scratches the area but this is not a cause for concern. Separating the mouse doing the biting from the others in the cage will usually put a stop to this problem.

Fighting Injuries

Occasional fighting between male mice sharing a cage is fairly common. If there are sustained periods of fighting, especially from one mouse in particular then that mouse will need to be removed. Mice will bite each other on the tail, face, back and genitals when fighting. They will not often draw blood, but if they do you should treat the wounds with disinfectant to reduce the chance of infection and further complications.


This article is intended as a guide to help pet mice owners be aware of any health issues their mice may be experiencing. If you think your mice are suffering from any health conditions you should always consult the advice of a professional veterinarian.

Addressing any health issues early and effectively will increase the chances of your mice making a full recovery.



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