Health Problems in Pet Mice
Before getting a pet mouse, understand the health problems that you might have to undertake as a fellow pet mouse owner.
When Your Mice Age
This article covers most health problems mice can suffer from. As mice age, their chance of having a health condition increases along with their diet, lifestyle, environment, and stress levels.
It is important to know that while most simple problems are easily cured with a trip to the vet and some antibiotics, some things cannot be cured. Mice are very tiny, fragile, and have a fast metabolism, but they do not have the same massive immune system as us humans and, therefore, cannot fight off illnesses efficiently.
You should always remember to thoroughly wash your hands before handling your pet or their food as they can suffer from human illnesses which can become fatal, e.g., cold, stomach bug, or food poisoning.
Tumours are common.
Tumours
Unfortunately, tumours are a serious problem in mice. Mice over the age of one year are at a much higher risk of developing tumours. Unlike rats, tumours in mice are much less likely to be benign and can turn malignant within 2–3 weeks.
Symptoms
- Swollen belly on one or both sides. May come on suddenly or over a period of time.
- A ball like a pea under the skin with no root that can be rolled around.
- A swelling or lump on any part of the fur that can be moved.
- Weight loss.
- Being hunched, lethargic, or waddling.
- Blood from the genital area.
- Head tilt or loss of balance and problems walking.
In younger mice, tumours can be removed through surgery at your local vet. The surgery can be risky, but it usually has a good outlook. Unfortunately, the majority of the time, the tumours will come back, but surgery can add a couple more months to their lifespan.
If the tumour has not returned within three months, your mouse may be lucky, and it won't return at all. A vet is very unlikely to remove a tumour in an older mouse and will advise the best course of action. Mammary tumours are by far the most common.
A lump does not always mean a tumour, especially if the mouse lives with other mice. It could be a cyst, abscess, or injury.
Abscesses
Thankfully not all lumps mean your mouse has a cancerous tumour. In younger mice or mice with cage mates, sometimes a lump can be an abscess. These are caused most often by bites that have become swollen and infected.
Symptoms:
- A swollen ball, when felt, has a root or stem under it and cannot be rolled around much.
- A scab, cut, or pus leaking from a wound.
- A swollen but squashy area of skin.
- Fluid draining from the infected area.
- When a vet attempts to drain, fluid comes out.
- The mouse may continuously groom, bite at, or rub the area through despite the discomfort.
These are very treatable, usually with antibiotics and fluid draining. You should always take your mouse to the vet for proper diagnosis as an abscess doesn't have to have a cut area, but most commonly, they do have some kind of skin lesion.
Fleas and ticks are common as well in mice.
Mites, Fleas, and Ticks
These are also a fairly common problem for mice, especially ones that are kept around other pets. Mites, fleas, and ticks can cause excessive scratching, skin irritation, baldness, and even in some cases, skin infections. They are very distressing and annoying to your pet and can be treated at the vet or using a suitable home treatment for mice and small rodents that cures these insects.
Symptoms
- Small black spots or bugs on the skin.
- Flaking or scaly skin.
- Baldness from scratching.
- Excessive scratching, grooming, rubbing, or obvious physical discomfort.
- Scabby skin, especially around the ears and legs.
- Small insects on the fur.
- An obvious tick attached to the skin.
Most of the time, it is just a simple case of mites that can be cleared up easily. Make sure you thoroughly read the packaging or have your vet administer treatment. You can prevent this entirely by only using high-quality wood shavings and bedding that have been tightly or vacuum-packed and purchased from reputable store shelves rather than farms, barns, etc.
If you are worried, you can freeze shavings/hay for 24 hours or put them in a very cold temperature before giving them to a pet to kill any potential bugs inside. Never use shavings you have found on the floor or from a sawmill that has been taken from the ground, as they could be contaminated or toxic. Don't allow your mouse into contact with wild mice; let them loose outside or allow other pets to touch them.
You will also have to keep an eye out for wet tail.
Wet Tail
This is a very serious illness that mostly affects hamsters; however, mice are no exception and can also suffer from wet tail. Wet tail is a serious intestinal disease that is caused by stress. An overgrowth of bacteria in the gut causes watery diarrhea with a foul odour that can become fatal within hours. There is NO home remedy, and it can only be treated by a vet.
Symptoms
- A foul smell coming from the cage or smelly diarrhea.
- Ruffled coat and dull eyes.
- Waddling or weakness of limbs.
- Loss of appetite and animal not drinking.
- Mouse sleeps a lot and becomes much less active.
- Dirty/wet bottom - usually brown or black in colour.
As I said before, the ONLY way to treat it is through antibiotics from a vet. You must take your animal immediately for treatment as there is no home treatment available, and it does NOT get better on its own. You can prevent wet tail by always keeping the cage clean, keeping the room quiet and comfortable and keeping stress levels as low as possible. It is more common in hamsters under 12 weeks and younger mice.
Uterine Problems
Uterine problems only occur in female mice, as males do not have a uterus (womb). These problems are more common in older females, especially ones that have been used for breeding or have had babies too young/old.
Symptoms
- Bleeding from the genital area.
- A gooey or smelly discharge around the genitals.
- Swollen belly.
- Constantly damp underneath.
- Ruffled coat, loss of activity.
- Waddling or problems walking.
- Incontinence.
- Protrusion from the genital region, e.g., something "sticking out."
It is very important to know that only a vet can diagnose and treat these conditions. In some cases, it is just an infection that can be cleared up in a few days with antibiotics. In others, it could be birthing difficulties if your mouse is/was pregnant, problems after the birth or even an internal tumour. In the case of a tumour, there is very little that can be done. To prevent this issue, please do not breed your mice.
Urinary Tract Infection
More common in older mice (one year or older) and especially in females. However, this can happen to either sex and can eventually become a serious issue. UTIs are caused when bacteria enter the urethra or grow inside the bladder. This is not usually a problem for mice kept in clean conditions all their lives with good health.
Symptoms
- Smelly or dark/discoloured urine.
- Blood in the urine.
- Squeaking or crying when going to the toilet.
- Incontinence.
- Being wet with urine that is yellow or brown underneath.
- Increased drinking.
UTIs are treatable only with antibiotics and should be caught ASAP to prevent them from spreading to the kidneys or turning to pneumonia. In most cases, they are not serious and clear up after treatment within a few days. Your mouse is likely in a lot of discomfort.
Sticky Eyes
There are two conditions. One is red tears which can be mistaken for blood but are actually caused by stress and are harmless. These resolve themselves within a couple of days. The second issue is conjunctivitis or allergy.
Symptoms
- Gooey or sticky eyes.
- Gunge around the eyes.
- Eyes are sealed partially or fully shut.
- Ruffled coat, hunched position, or seems unwell.
- Sneezing, coughing or watery nose/ears.
Most of the time, this is not serious and improves after being bathed with a gentle cotton swab and having the bedding changed to something else. Use dust-free shavings rather than sawdust and make sure all surfaces are wiped down and no chemical cleaning residue is left behind. You can take your pet to the vet for eye drops or antibiotics if an infection is present.
There are two conditions of sticky eyes that your mouse is prone to getting.
Injury
Fighting, being dropped, being squashed, being poorly handled, or accidental toy injury are all problems that mice can face. Fighting between males is the most common cause of injuries, with poor handling being second and injury from toys being third.
You should not ever keep two males together as they will fight to the death, and once blood is shed, they should be parted and never put back together again. Females can live happily in pairs or small groups without any fighting.
Avoid using wheels with grating or open slats. These are very dangerous as little legs, tails or necks can be trapped and snapped in them as well as being caught and toes pulled off or cut. Always use flat plastic toys, saucer wheels, or sealed plastic wheels to prevent injury, and make sure any other toys given are safe for mice, fitted securely to the cage, or you follow all directions properly.
You can lift a mouse gently but firmly using the root of their tail and a hand underneath to steady them. Always cup them properly and hold them over a soft surface against your body. Never let go of a mouth that is frightened or bites you, and don't allow untamed pets to run around on your shoulder, as they can easily fall off and get hurt. Never pull a mouse off of cage bars or when they are gripping something, as you can pull the skin off their bones or cause them serious pain. Mice do not make good pets for children.