I was gone for 48 hours and when I returned home there was a dead mouse in my cats’ water dish. It could have been there for 48 hours or just 1 hour, I’m not sure. Should I be worried about any potential infection from them drinking from the water dish?
Rodents such as mice can carry a number of zoonotic diseases (diseases that can be transmitted to people) as well as diseases that can affect animals. Before talking about your cat, I want to make sure that you take care of yourself. It is important that you wash your hands after handling everything and disinfect the water bowl. If you are at all concerned for your own health, I would encourage you to see a doctor.
Mice can carry include leptospirosis, salmonella, henta virus, and a number of other diseases and parasites that can transmit to your cat. See this link for more details:
https://iacuc.wsu.edu/zoonoses-associated-with-rodents/
As for your cat, it is common for cats to hunt mice and it could have been a mouse that your cat actually caught and put there herself. I would recommend seeing a veterinarian make sure your cat is properly vaccinated and either dewormed or checked for parasites by a veterinarian. Here is a link for more information about vaccinations:
https://www.vetbabble.com/cats/health-cats/vaccinations/
There is no perfect way to prevent illnesses from rodents, but this will at least give you the best protection possible other than preventing exposure. If you see any signs of vomitting, diarrhea, or lethargy, be sure to book an appointment with your veterinarian straight away.