“I have two hamsters at home. Recently I have noticed, that a round one appeared on the head of one of them, bald spots, which are covered with gray scabs. From under these scabs, pus sometimes comes out. Could such symptoms be a sign of a serious one?, serious disease? Is there any home remedy to cure it?”
Your hamster has impetigo. You should isolate him from his companion immediately. The cage should be thoroughly disinfected with a solution of gray soap (1 tablespoon for half a liter of water). Apply the same solution to the bald spots on the hamster's head, however careful, so that the impetigo does not transfer to healthy skin.
After removing the scabs, the diseased areas should be brushed with 10% salicylic ointment.