Hamsters are quite hardy as a rule, but they are so small that it is easy for a disease situation to quite quickly take a hold and totally overwhelm them. It is vital for the owner to establish handling and a lot of contact right from the outset because then it will be easy to check is the hamster is healthy. In the case of skin diseases, the hamster has quite a lot of problems that can trouble it, although most are easy to treat.
Things that are not skin diseases!
A male hamster has scent glands in its skin, in various places depending on breed, but basically, think hips. These can look like a skin disease as they can appear greasy or bald and if the animal has been grooming the scent into its coat it may look wet. The presence of this gland is totally normal and is used by the male to signal to the female that he has reached sexual maturity. As this can happen when the hamster is as young as five weeks old, these glands will probably begin to be noticeable almost as soon as a youngster is brought home for the first time. For the novice hamster owner, they can look a lot like a skin condition, but are nothing to worry about. That said, they should be monitored as they are a common site of tumours and so if they change shape they should be checked out by a vet. A hamster will also tend to lick and gnaw at an injury, so although this behaviour should also be checked out as it may indicate a broken limb, puncture wound or bite, it is not in itself a skin disease.
Things that are skin diseases in hamsters
Mite infestation is a very common cause of dermatitis in hamsters. The mites live naturally on the skin and can sometimes be seen in skin folds around the neck and legs. They are harmless to a healthy animal, but if the hamster is old, malnourished, stressed or suffering from another condition which might be weakening its immune system, the mite population will become overwhelming and the owner will begin to notice baldness (alopecia), crusting of the skin with dandruff and excessive scratching. It is quite normal for hair to fall out in reasonable quantities at various times of the year in healthy animals as they get older, so alopecia alone is not really a cause for concern. There are two different types of mite which affect hamsters and it is usually the one not visible to the naked eye demodex aurati which causes illness in elderly animals, most often the males. In series cases of mange a bacterial infection can set in and this is typified by pus production. The condition is extremely well advanced before this happens and any responsible owner will have hopefully spotted it long before this stage.
Hamsters suffer fungal infections if they are kept in enclosed habitats where the humidity is high. Hair is lost in a circular pattern and so the fungus is given the generic name of ringworm. Other problems include infected bites female hamsters in particular can be quite aggressive and their bites are deep and painful. These can become infected and the skin can develop nasty pus-filled sites which need the attention of a vet to prevent septicaemia. Hamsters can also harbour temporarily cat fleas, so excess itching may be due to an infestation, but it doesnt take much to spot a flea on a hamster, as they are relatively large. Elderly hamsters tend to show more skin problems and some of these are hormonal; the hamster equivalent of male pattern baldness in humans. The hamster, if otherwise well, can be left alone as it is not in any distress
Hamsters get allergies too
A fairly common cause of skin problems in hamsters is that they have become allergic to their bedding or other pollutant or irritant in their environment. Cedar wood shavings should simply never be used for bedding for small animals. Some people use them because they smell nice, but the oils in them are far too strong for an animal the size of a hamster and quite bad skin lesions can occur if they are used. Dyed paper bedding is also a common culprit and this sensitivity may affect just one hamster in a group and make it feel quite wretched with sneezing, scratching and dermatitis. Proprietary brands of hamster food often contains dyed pieces of cereal to make it look more colourful and appetising (to the owner not the hamster) and if your hamster is exhibiting signs of allergic reaction, it would be good policy to avoid these and go to completely natural foods, at least for a while.
Treatment of Skin Diseases
Treatment will vary with the cause of the skin problems. Antibiotics will clear up any superficial skin infection and administration of this can be by drops or topically on the site of the problem. If the hamster has a mite infestation that has got out of hand, a course of invermectin as drops or in very bad cases, an insecticidal dip. There is one species of mite which is very virulent but mercifully rare and this will need a sulphur dip to completely eradicate it. One top of any treatment it goes almost without saying that the bedding should be changed and the habitat thoroughly cleaned before replacing the hamster. In a healthy animal the treatment should be completely successful but the owner may have to accept in the case of an older animal that the problem may recur and that any treatment will be a holding measure only to keep it as comfortable as possible with a reasonable quality of life.