Common Hamster Health Problems (That You Need To Look Out For)

By Dawn | Hamster Health
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In this post I’m going to talk about some of the common health problems you might encounter whilst caring for your hamster. 

This isn’t an A to Z of every single health problem there is but it will help you to answer the most common queries that first time owners come up against and worry about. 

Minor health problems can often be picked up early by noticing changes in your hamster’s movement ,appearance and attitude. 

By catching some of these minor problems early then you can potentially prevent more serious health issues from developing. 

This will also help you to avoid expensive and ongoing vet bills.

Bar Rub

Bar rub is a problem that has existed ever since hamsters have been kept as pets. 

Basically what happens is that hamsters gnaw on the bars of the cage continuously while sliding their face up and down. 

The result is that you get an area of skin which is completely devoid of any hair.  In extreme cases you can get bleeding and scarring on each side of the nose or mouth.

To prevent this from happening I recommend giving your hamster something to chew.  You can find the chews that I recommend giving to your hamster in this blog post.

If you find your hamster gnaws on the cage bars in one particular place, then you can try to put the wood chews in that position.

Sometimes however, it doesn’t matter what you give to your hamster, they may simply enjoy gnawing at the cage bars and if it continues your hamster will have a permanently scarred face. 

The only option you have at this point is to get a plastic or a glass tank cage.


Believe it or not it is possible for your hamster to catch colds and flu from humans. 

if you happen to have a cold or flu then you need to avoid any contact with your hamster, as you are very likely to pass it on to them. 

The symptoms are pretty much the same as in humans but things to look out for are rapid breathing, a wheezy chest, a cough, sneezing and spluttering fits and even a runny nose. 

If your hamster displays any of these symptoms then you need to isolate it from any other hamsters that you may have and then seek veterinary advice.


Cuts and scrapes on hamsters tend to bleed a lot but they do heal quick and minor cuts and nicks heal on their own. 

If it is a minor cut then bathe the cut with cotton wool dipped in tepid water. For Larger cuts or cuts that have signs of infection, you ‘ll need to seek veterinary advice. 

Never be tempted to use antiseptic creams on your hamster as these are designed for human use only.


A hamster can dehydrate very quickly especially when subjected to sudden heat or when there is a lack of water. 

The lack of water could be down to a blocked water bottle so be sure to check the water level everyday.  

You can check for blockages by running your finger under the ball bearing and if your finger is wet, then great, if not, then you know there’s a problem with the bottle and it may need to be replaced.

Your hamster cage could also be causing your hamster to be dehydrated. Plastic or glass cages that are left in sunlight can cause the heat to intensify inside the cage and despite water being available inside the cage, your hamster can be quickly overcome before it is able to drink. 

Never leave the cage in direct sunlight and it goes without saying to never leave your hamster in a car. 

Always make sure that your cage is kept at the right temperature.  It’s a good idea to put a thermometer inside the cage because the temperature inside the cage can be very different to the temperature outside the cage. 

You can read more in my blog post about positioning your cage in the optimum location.

If your hamster is dehydrated it will likely appear limp, almost like in a deep sleep and won’t react to any handling. 

In this case you need to cool down your hamster as soon as possible and get water into your hamster’s body quickly.

Dry ears

It is often possible to tell the age of a hamster just by looking at their ears. Young hamsters have hairy ears whilst older hamsters only have a little hair on their ears and they may appear shiny. 

As your hamster gets older, the skin on your hamster can become flaky which can become thick and start to irritate your hamster.

If this happens, then you can rub a little vegetable oil, petroleum jelly or baby oil between your index finger and thumb and then rub it onto your hamster’s ears. 

This will help to relieve the flakiness temporarily.

Dry skin

Long-haired syrian male hamsters can develop flaky skin when they get older, especially on their lower back. This looks a little bit like dandruff. 

If it is not treated, dead skin can build up which can crack and infection can set in and can cause irritation for your hamster. 

If this happens then you need to see your vet.

In the meantime, regular grooming can help, as can trimming your hamsters hair to about half its normal length.

Eye problems


Entropion is basically a condition whereby the eyelid turns inwards and can irritate the eyeball.  If you notice that you need to see veterinary advice.

This is mainly seen in rex (curly-coated) syrian and dwarf hamsters.

Foreign bodies

It’s common for hamsters to get things in their eyes such as food or wood shavings.  Usually these things are washed away by their tears, but if not, you need to seek veterinary advice.

Gummy eyes

Gummy eyes are usually seen in older hamsters.

Basically this condition is when one or both eyes won’t open when your hamster wakes up but is then able to open its eyes when it has groomed itself.

To treat this you can gently wipe over or bathe the eye with lukewarm water and cotton wool.  This will help to moisten the closed eye and allow it to open.  

At the very least it will help encourage your hamster to groom around the eye.

Loss of eyes

Sometimes baby hamsters can lose sight in one eye when the mother retrieves the wondering baby and grabs it in whichever way it can.  

If your hamster does have lost eyesight then it’s good to know that hamsters cope well with this; mainly because of their extreme sense of smell and hearing.

Damaged eyes in young hamsters also tend to heal well.

If you notice that there is damage to one or both of the eyes or an infection has developed, then it is important to seek veterinary advice to prevent the loss of eyesight. 


Although hamsters have excellent hearing and a great sense of smell, their eyesight isn’t brilliant. 

Hamsters are in fact short-sighted which means they are unable to perceive depth and height. 

Because of this it is very easy for them to walk off the edge of a table or the edge of a platform in their cage. 

Falls can wind your hamster if they fall far enough and even if they don’t sustain any injuries, they can suffer from the shock. 

In which case you need to keep them in a quiet place and allow them time to recover. 

If you notice that your hamster isn’t putting any weight on a particular limb and appears to be in pain then one of the limbs may be broken. 

If this is the case, remove any wheels and toys from the cage and talk to your vet to discuss your options.


Hamsters don’t tend to naturally go into hibernation but during the cold winter months they may go into a semi-dormant state whilst they’re asleep. 

Captive hamsters however, like your pet, can be triggered into going into hibernation in the event of either a big drop in temperature or a complete change in circumstances.

Many hamster owners will assume that their hamster is dead when their hamster is in hibernation because their breathing, heartbeat and temperature drop so low that they are completely unnoticeable. 

Your hamster will also feel cool or cold to touch. 

What you should do is check for the twitch of a whisker and look for tiny chest movements. 

If you think your hamster is in hibernation, then place your hamster and the cage in a warm place and allow their body temperature to rise.  

Alternatively you can put a hot water bottle under the cage. 

Within about half an hour, your hamster should start breathing normally and its heartbeat should return to normal and will resume its normal routine. 

To prevent this from happening in the future, make sure that you have extra bedding in place and put the hamster cage where the temperature is constant especially during cold weather.

Hip spots

Hip spots are also known as scent glands or flank glands and they are situated above the hip.  They can sometimes worry new owners when they’re seeing for the first time because they can’t be seen very well when the hamster is young. 

These hip spots appear on both male and female hamsters but they are more obvious on males. 

Basically it means that your hamster has become sexually mature and is in good breeding condition.  Male hamsters tend to spend a lot of time grooming these two spots and so they become more obvious. 

Both male and female hamsters rub or slide the spots on the side of the cage a way of marking their territory.

Lumps and bumps

Lumps and bumps panic many hamster owners but most of them are nothing to worry about.

Testicular lumps

Many people panic over the size of their hamster’s testicles which become much more noticeable as young male hamsters mature.  They also become more noticeable if the hamster is warm i.e when they’re sleeping or being handled.

Usually when the hamster returns to the cage and has a chance to cool down the testicles will retract and become less obvious. 

Things to look out for are if one or both of the testicles become distended, hard or don’t retract.  In this case, you need to see a vet as this may be a testicular tumor.

If you own a male chinese hamster, then the testicles on these hamsters are always fairly obvious but usually this is nothing to worry about.

Mammary lumps

Sometimes hamsters can develop mammary tumors which are normally alongside or underneath the nipple.  These can be firm to touch and tend to grow rapidly, so it’s important that you seek veterinary advice if you notice one of these.

Occasionally nursing female hamsters may develop mastitis which can appear as swelling around the mammary gland area.  Again, seek veterinary advice if you notice this in your hamster.

Facial lumps

If you find that your hamster’s face suddenly gets larger, then chances are, they are simply gathering food or bedding in their pouches. 

However if one or both sides of your hamster face are continually swollen then you may need to investigate. 

What do you need to do is watch to see if your hamster empties its pouches.  If it does, great, if not, it might be that the pouch is compacted and may need emptying under anaesthetic. 

Other reasons are that your hamster may have a tooth abscess or an infection.  Either way you need to see a vet.

Other bumps

Elderly dwarf hamsters can sometimes develop soft lumps on their chest and tummy which is normally not a problem unless they become ulcerated, in which case, you need to see a vet. 

Some lumps may have to be removed but it is not always possible as your hamster might not survive the operation. 

Finally some scent glands on male dwarf hamsters can be confused with a soft lump, so again, you don’t always need to worry.


If you have a large cage, you have an exercise wheel or playbox then chances are, your hamster is not going to suffer from overgrown nails. 

Overgrown nails tend to only occur when your hamster gets older and less active.  Overgrown nails also tend to occur more in Campbell and Winter White hamsters as opposed to Syrians.

If you notice that your hamster’s nails curl back on themselves, then there are some things that you can do to help reduce their length.

These include:

  • Adding rough surface stones to your hamsters cage.  You can also hide food amongst them to encourage your hamster to climb on them.
  • Putting the stones under your hamster’s water bottle to force your hamster to climb on them.
  • Adding a sand bath to your hamsters cage.
  • Adding raw wood toys, a walnut, sunflower seeds or monkey nuts to your hamster’s cage will encourage your hamster to use their claws and teeth to get into them.  This has the added benefit of helping to wear their teeth and claws down at the same time.

Scent glands

All hamsters have scent glands.  On Syrians they are located over the hips, but if you have a Campbells or Winter White hamster, then they have a very noticeable scent gland on their tummy, but this is usually nothing to worry about. 

If you think that their appearance has changed somewhat, then get it checked over by a vet because some scent glands can develop tumors.


Like humans, hamsters can have strokes.  You’ll likely notice that your hamster has had a stroke if they appear to rock forward and backwards with each step that they take when they walk or when they’re lying in their nest. 

Strokes can cause your hamster to lose function in a limb or they can become disorientated.

Hamsters can also have mini strokes like humans do, but unfortunately, more of these can follow. 

If your hamster has a stroke the best thing that you can do is put them back in their nest with food and water close by and monitor their recovery

Teeth problems

The front incisors on a hamster grow throughout their entire life, like with all rodents.  So it’s important that you keep tabs on them to make sure that they don’t grow too long and that there aren’t any issues with them. 

One common thing is that hamsters can chew on the cage bars which may be because their teeth are too long.

Hamster teeth that are too long, can also cause your hamster to lose weight because the discomfort from their teeth might be preventing your hamster from eating.

The best remedy for over long teeth is to prevent them from becoming too long in the first place by providing your hamster with ample things to gnaw on in the cage. 

However, despite providing things for your hamster to chew on, you might find that your hamster’s teeth still need clipping. 

Never be tempted to do this yourself especially if you’ve never done it before.  Any vet will be able to clip your hamsters teeth with ease.

Gnawing on hard objects such as cage bars or hard food can also result in a broken tooth.

If you notice blood in and around your hamster’s mouth, then this can indicate a broken or a pulled tooth.  Sudden weight loss can also indicate that there is something wrong with your hamster’s teeth but it can also mean that your hamster is unwell. 

If your hamster breaks a tooth then the corresponding upper or lower tooth will continue to grow as there is nothing for it to bite against. 

If your hamster loses a tooth, then the corresponding tooth will need continual clipping otherwise it can grow into the opposite gum. 

You will also need a vet to clip the remaining teeth but may decide to train you to do it yourself, if you need to do it on a regular basis.

Thinning fur

Hamster fur usually gets thinner as they get older and their belly may become completely bald. 

Your hamster may even lose patches from the flank or their limbs.

This isn’t inevitable however because some hamsters don’t lose any fur at all as they get older. 

Nursing female hamsters can also lose fur on their flanks when they have raised a litter.  This normally grows back once the hamster is back in good condition.


Twirling is basically when your hamster runs around and around on the spot or in small circles.  If this happens very suddenly, it could be a sign of an inner ear infection in which case your hamster will need antibiotics from a vet.

If your hamster is very young and they are twirling then this could be an indication of brain damage.  This is not treatable but may not be immediately life-threatening.

Urine changes

If you notice that your hamster’s urine changes in color then this may indicate health problems so you need to check it regularly. 

If you notice that the shavings in the corner of your cage have changed color, this could either be a symptom of a urine infection or it could be something as simple as a change in the type or color of woods shavings that you use. 

Dietary changes can also affect your hamster urine colour.  This is especially the case with beetroot which can give you a hamster’s urine a reddish tinge to it. 

If you have eliminated all such external possibilities and the problem still persists, then you need to get your hamster seen by a vet, especially if your hamster looks under the weather.

Weight loss

When it comes to weight loss, you are looking for sudden and very noticeable weight loss which could be an indication that your hamster is not well.  Hamsters tend to lose weight naturally as they age but this is a gradual process.

The first and most obvious thing to check is your hamster’s teeth.  Your hamster may stop eating because of discomfort from a broken or overgrown tooth. 

The next thing to check is the water bottle, to see if it is working.  If your water bottle is blocked then this can lead to dehydration, especially if the weather is hot. 

Finally, if you think that your hamster has lost weight and you feel that something isn’t quite right, then monitor your hamster closely for signs of illness and if you are worried see your vet.

Wrapping up

It’s not always easy to tell whether your hamster is ill or not, because they can’t tell you and they do a very good job at covering up their symptoms.  However, there are some tell-tale signs that you should look out for such as weight loss, loss of appetite, huddling in a corner and diarrhea.  

Healthy hamsters exercise on their wheel and if your hamster is anything like my hamster, always eating!.  Healthy hamsters are also alert and inquisitive.  If you think there is something wrong with your hamster, see your vet as soon as possible before it develops into something more serious.