Only syrian hamsters get wet tail. The other small animals can get severe diahrroea, but not wet tail, if I am correct. You can read my article on wet tail here: http://www.geocities.com/calhamassoc/WetTail.html If you find a small pet breeder in your area most of them can guarantee the health of your new pet. I get my hamster breeder friends and who are also members of the California Hamster Association. They all have very hugh standards for their animals as pets and for show. I also know rat, mouse, rabbit, and guinea pig breeders. It is pretty much the same for them... A lot of pet store animals are always sick.
Also, I know several hamster breeders around your area in Rhode Island, Pennysilvania, New York, Maryland, etc, as well as some of those people breed other things as well..