The number one thing you need for a healthy hamster is a dry, clean cage. A damp cage is bad for hamsters nor do they like it. I wouldn't recommend putting water in a dish as it will most likely be spilled or the hamster (especially babies) may drown.. Always take uneaten fruits or vegetables out of the cage, not only can they also dampen the dage, they can also rot. If your hamster's bedding is ever wet for any reason, change it right away.

Also always make sure that no pests like roaches, mites, or any other bug get into your hamster's cage. If this does happen, make sure you clean the cage with hot water and mild soap. Rinse it VERY well and dry it completely. Supply your hamster with fresh bedding.

     Also be sure that wild mice or rats don't have access to your hamster's cage. They carry all kinds of parasites.

     Your hamster will not usually get mites or fleas, but if they do, sprays for this can be bought at pet stores. Always make sure when you bring home a new hamster, he is in good health before putting him with your other hamsters.

Hamsters can catch colds from drafts, people, or other pets. A hamster's symptoms are: runny nose, sniffles, and other obvious cold symptoms. If one of your hamsters comes down with a cold, he should be separated from the others. It'd probably be good idea to keep an eye on the others for cold symptons also. Make sure his cage is warm, dry, and draft free and he gets fresh water. Clean out all the old bedding and put new bedding in. Do this after he has gotten better so he doesn't catch it again. Other signs are listlessness, dull eyes, lack of appetite, and a rough coat.

The hamster's teeth can break off, get cavities, and possibly decay. Hamsters' teeth keep growing though. That's why they need a chewing block in their cage.

     Broken teeth can prevent him from eating and malnutrition, if not starvation. If he does have broken teeth, clip the adjecent teeth with heavyduty nail clippers. Bring him to the vet if you feel uncomfortable doing it yourself.

     Check your hamsters teeth regulary for cavities or signs of unusual discoloration. Wear clean gloves when you do this. If he has a loose tooth, you can probably pull it out with your fingers, holding the blood with a bit of gauze held firmly. If a tooth is in bad shape but not loose, let a veterinarian extract it.

If your hamster is caged by himself, he'll rarely have any cuts, wounds, or bites. While dwarf hamsters usually can be kept together, fighting may occur. If he gets a minor cut within reach of his tongue,  there will be little need to worry. Him licking the wound will prevent infection. Otherwise treat them with a mild antiseptic applied with a cotton swab. Do not bandage the wound, if it's bleeding freely, hold a bit of gauze firmly against it until the wound stops bleeding. A injured hamster should never be kept with others, they may attack him.

Your hamster's droppings are a good way to determine his health. If they are rod-shaped and of normal consistency, all is well. Loose, watery droppings indicate a diet of too many fresh fruits and vegetables. Hard, dry droppings indicate that more fresh foods are necessary. Constipation is more common among young hamsters, so make sure they get plenty of fresh water.