Hamsters can get sick in many ways. If you feed them candy or things that they naturally don't eat, they can get sick, since they are not on there natural diet, which are seeds, veggies, fruits and sometimes you can feed them bugs or shredded meat, and of coarse water for a drink. They can also get sick if they are too old and about to die, or if they get a flu! Yes. Hamsters get flus. EVERY animal can get a flu! When i was walking, i saw a dead crow, and misquitoes were flying all around it. Then, we called the humane society to see what caused it to die. It was west nile virus that killed the crow! So, that proves my point. Animals can get sick to. Anways, back to the hamsters get sick. So, yes. Hamsters get sick by eating not their natural diet, and if they get old.