It seems like all I do is talk about cats on this blog. But I don't want to completely forget that we serve a few pocket pet owners, too.
Most owners of rats and hamsters and such are unaware of the risk of a couple of significant zoonotic diseases they can spread: Salmonellosis and lymphocytic choriomeningitis virus.
Salmonella is a gastrointestinal bacterium that is famous for causing food poisoning. But some pets can commonly carry it - reptiles are the most common source, but rodents such as pet rats and hamsters and mice can also carry it. Never purchase pet rodents that look sick, or share a cage with ones that look sick. Always use good hygiene when handling them, washing up with soap and water afterwards.
Lymphocytic choriomeningitis virus (LCMV) causes a serious viral infection in humans and can be acquired from mice, hamsters, and guinea pigs. As with Salmonella, good hygiene is important, as is ensuring that wild rodents cannot have contact with pet rodents. Symptoms of LCMV resemble those of influenza but can result in neurological disease and birth defects.