Hamsters may be small, but they are full of character and often become an important member of the family despite their relatively short lifespan. As a naturally nocturnal prey species, they can be secretive when it comes to displaying signs of illness or weakness. This can make it tricky to pick up on subtle clues that may suggest your hamster is feeling under the weather. So how can you tell when your hamster needs to see a vet?

General signs to look out for which may suggest that your hamster is feeling unwell include: 

  • reduced activity such as staying in the same place for a long time
  • sitting in a hunched position with the eyes closed
  • eating less food 
  • breathing more quickly or heavily than usual. 

Some problems produce more specific symptoms and signs which can give us a better idea of what might be the matter. 

Observing and handling your hamster regularly can help you pick up on signs of illness as early as possible. Here are a few of the most common reasons for hamsters needing to see a vet, and what to look out for at home.


Diarrhoea, sometimes referred to as “wet tail”, can be due to diet, an intestinal problem such as a viral or bacterial infection, or secondary to another illness. Treatment with certain antibiotics can also result in diarrhoea.

Feeding different foods, particularly excessive amounts of fresh vegetables, can cause the droppings to become soft. If your hamster is eating well, active and bright but has soft or loose droppings, try withholding fresh vegetables for a day or two to see if this helps. However, a hamster that is generally unwell, eating less or quiet as well as having diarrhoea should be taken to the vet straight away as illness can progress quickly. Severe diarrhoea can result in dehydration, weight loss or rectal prolapse, and can be life-threatening if left untreated.

True “wet tail” is caused by a bacteria called Lawsonia intracellularis which causes severe diarrhoea in young hamsters around the time of weaning. This is highly infectious and often fatal. However, many vets will refer to diarrhoea as “wet tail” regardless of the cause. 

Sneezing, snuffling and breathing problems

Respiratory disease is another common reason for hamsters to see the vet. Signs include sneezing, discharge from the eyes and nose, swelling of the eyelids and increased breathing rate or effort. Hamsters with breathing problems will often seem generally unwell and may be hunched-up, quiet in themselves and off their food. If your hamster is showing these symptoms, it is important to take them to the vet as soon as possible. Hamsters can become severely unwell very rapidly, especially if their breathing problem is related to a lung infection. 

Mild signs of upper respiratory disease, may be associated with an irritation. These are occasional sneezing, a slightly wet nose or mildly swollen eyelids. If your hamster is otherwise well, try avoiding potential irritants, such as air fresheners, cigarette smoke or dusty bedding to see if this helps. It is important to clean the bedding regularly to prevent build-up of ammonia fumes from urine. This can cause irritation to the eyes and nose. Making sure the enclosure is warm enough and well ventilated but not draughty also helps with this. However, if your pet develops other symptoms or seems to be feeling unwell it is safest to get them checked by your vet.

Skin disease

Skin problems are common in hamsters, with symptoms such as itching, fur loss, scabs or sores. Skin disease tends to be easier to notice than other forms of illness. The signs are clearly visible during handling or when watching your hamster. Common causes include external parasites such as mites, fungal infections such as ringworm and physical injuries from other hamsters including bite wounds or nibbling of the fur, known as “barbering”. Ringworm can be passed to humans so take care when handling hamsters with skin disease. 

If you have seen another hamster nibbling your hamster’s fur away and there is no damage to the skin, you can try separating the two hamsters. Alternatively, try providing them with a larger enclosure with more hiding places so they each have their own space. If the cause of the skin problem is not clear, it is important to take your hamster to the vet for a diagnosis. Treatments vary greatly depending on the cause of the problem and many skin diseases can look similar. 

Rarely, skin problems can have a more sinister cause, such as certain cancers.

It is also important to know that hamsters possess scent glands which are round or oval areas of thickened skin which may be greasy. Syrian hamsters have one on either flank, whereas Dwarf hamsters have a single scent gland on their underside. These are normal features but can become inflamed, infected, impacted with waxy material or occasionally cancerous.

Cheek pouch disease

It is normal for hamsters to collect and store food in their cheek pouches, often transporting it to their bedding area to keep for later. Some hamsters try to fit large pieces of food into their pouches, which can be quite comical to watch. However, cheek pouches can also cause some problems.

Food can become impacted within the pouch causing inflammation and infections, in some cases leading to abscessation. Sedation or anaesthesia is often required to remove the impacted material and clean the pouch. 

Cheek pouches can also prolapse. This essential means that the pouch turns inside-out, protruding from the inside of the cheek and out of the mouth. The pouch can sometimes be replaced easily if the prolapse is very recent. However, sometimes the everted pouch becomes damaged, requiring surgery. Either way, the problem should be dealt with by a vet as the pouch tissue is delicate and easily damaged. Pouches which prolapse again following replacement also benefit from surgery to permanently replace the pouch using a suture. 

Cheek pouch problems may be associated with dental problems, which is another good reason to ask your vet to check your hamster over.

Abdominal Swelling

A swollen abdomen can occur with several diseases. Handling your hamster regularly makes picking up on small changes to their body shape or size easier. However, significant abdominal distension may be seen by just observing your hamster, particularly if they are not very fluffy. 

Abdominal swelling can be caused by tumours, cysts or fluid within the abdomen. Cysts on the liver are not uncommon, and fluid can collect as a result of heart disease. Your vet may be able to identify the likely cause by examining your hamster, or may suggest investigations such as an abdominal scan. Abdominal swelling usually indicates serious illness, often with a poor prognosis. 
Handling and interacting with your hamster on a regular basis and getting to know their habits can help you pick up on any changes which suggest they are not feeling themselves. If you notice anything out of the ordinary for your pet or any of the signs mentioned above, it is best to take your hamster to the vet to get them checked over and for any treatment they may need.