Any lump which appears on an animal should be checked out by the vet. It is most likely an abscess, but may be a tumour and it is not possible to tell without a qualified person seeing it. An abscess is quite likely in a hamster as they can get quite aggressive with each other if kept together and the bites can often get infected.
Signs to watch out for
Obviously, an abscess can become very large, very quickly and any fast-appearing lump should be attended to immediately. A lump coming up that fast is not likely to be anything but an abscess, but it is vital not to make an assumption; any swelling or abnormality that you notice must be a cause for a visit to the vet. If your hamster is very friendly and inquisitive you will probably see it more often than the more reclusive and shy kind. Therefore, you may see an abscess almost before it becomes one and in this case you are ahead of the game. The area of the bite or injury (the most common causes of eventual abscesses) may look wet. This is because the hamster will have been licking it, following the original injury, partly because it will have hurt and also as an automatic response to the on-going injury site and an attempt to keep it clean. The area may look red and slightly swollen. This is a good time to take the animal to the vet as antibiotics at this stage may well prevent the abscess appearing at all and this will be very much to everyone’s advantage – not least the hamster’s!
What to do if the abscess develops
If the owner misses the first signs of an abscess and the hamster has a swelling on the body there is really only one course of action and that is to take the animal to the vet. If the abscess has opened or if there is an open wound, it should be kept clean until the vet can be practically reached. This can be done by clipping the hair around the site (wet the scissors blade so that the hair does not fall into the wound) and wash the site carefully with saline made with boiled water. This is unlikely, though. Most abscesses will have to be lanced by the vet – on no account try to do this yourself – and if it is severe it may have to be opened surgically and cleaned out. The resulting small wound may have a stitch – these are usually dissolving ones so will not need removing later. If the abscess is on the face it is important to make sure that it is not an impacted pouch. This will still need to be attended to by the vet but the urgency is not quite so great. Hamster pouches are dry, not moist like a mouth cavity, and sometimes food will get stuck. A vet will be able to wash the pouch out and remove the food. This is important as food may develop fungus or bacterial content which will be very bad for the hamster.
Diagnosis and treatment by the vet
An abscess is easy to diagnose as it will be hot, red and swollen. The vet will check that there is an injury site somewhere on the surface of the abscess; this is usually quite clear. If there is no injury, he will check that it is not an abscess caused by anything internal. An osteomyelitis may present as an external abscess; this is usually on a joint and so is easy to determine. A swelling with no attendant redness or heat may be a tumour. These are common on the scent glands for example, but the vet will be able to decide usually without the need for further tests. On definite diagnosis, the vet will lance the abscess, and clean out the cavity with saline. Antibiotics will be prescribed to ‘mop up’ any remaining infection and the site of the abscess will need to be carefully watched for a while to make sure the cavity does not fill back up with pus.
Prevention of lumps
It is not really possible to prevent an abscess forming if there has been a puncture wound which becomes infected; it is a natural reaction of the body to send white cells to the site of a wound and it is these which form the pus which fills the cavity which develops. Sometimes an abscess will resolve itself and will be reabsorbed. If this seems to be happening at the point when it is first noticed, then it can be monitored for twenty four hours to make sure it is really reducing in size. Hamsters do tend to bite each other, either in play or mating and if there seems to be one animal in particular that is aggressive, it may be best to remove it from the group. Not all breeds of hamsters enjoy being together. Syrian hamsters are solitary in the wild and will not really tolerate another in the cage as they are very territorial. Some hamsters which pet shops and books say will live together – dwarf breeds such as Chinese or Russian, for example – may not actually tolerate each other in practice. A pregnant female will become highly territorial and will bite ferociously if left with others. And this means that she will bite the owner as well, so it is unwise to let children handle any hamster if they (the hamster, not the child!) tend towards aggression; the bites are very deep and painful and a hamster doesn’t just bite and let go; it hangs on in there.