Abscesses --------- Abscesses are most often caused by bite wounds from fighting. These wounds become infected, forming abscesses that appear as firm, painful lumps under the skin. Abscesses from injuries other than bite wounds may be indistinguishable from those that result from fighting. Abscesses of one or both cheek pouches are also very common among pet hamsters. These commonly result from penetrating wounds to the lining of the pouch caused by harsh foods or bedding materials. It may be very difficult for you to know whether a swelling in the area of the cheek pouch is an abscess or simply food or bedding being temporarily stored within the pouch. Generally speaking, the swelling resulting from a cheek pouch abscess persists, but a pouch swelling from stored food or bedding disappears when the animal empties its cheek pouch. If an abscess is detected or suspected, the abscess must be opened and the pus drained or removed by a veterinarian. An appropriate antibiotic also will be prescribed. Furthermore, the underlying cause(s) for the abscess must be eliminated, if possible.