Rodents carry disease. I’m not going to go down the Internet rabbit hole and debate whether the guinea pig is a rodent or not, but I will let this quote from the CDC do it for me:

This outbreak is a reminder that pet rodents such as guinea pigs, regardless of where they are purchased or adopted, can carry Salmonella bacteria even when they look healthy and clean…Pet rodents are not recommended as pets for children younger than 5 years, and should not be kept in childcare centers.

Yes, the adorable pet guinea pig/rodent you are keeping as a pet could be carrying the Salmonella bacteria. Nine people in ten states have reported Salmonella cases linked to pet guinea pigs, prompting an advisory from the CDC. Symptoms include diarrhea, fever, and stomach pain. The illness usually lasts four to seven days and most people will recover without treatment. In some cases, hospitalization may be required. Salmonella can be more severe for children under than five, older adults, and those with weakened immune systems.

The CDC’s advice for pet rodent owners: wash your hands, don’t eat or drink while playing with your pet rodent, and be aware that any surfaces your pet rodent scurries across could be contaminated. Most importantly (in my opinion): “do not kiss, nuzzle, or hold pet rodents close to your face.”