The virus came from eating food with the same paw that handled the underside of the robot & possibly licking a wrapper that was inside the robot.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2878247/

There's definitely fecal material on the underside from dogs.  The inside is more mysterious.  All food is wrapped up, but 24 hours before the symptoms, the lion kingdom wasn't the most sanitary.  It was the worst case of norovirus a lion ever had.  It was a reminder that the dirt on the last 10 years of vehicles isn't always dirt.

Having said that, the lion kingdom got norovirus 2 days after an outbreak happened in a Chico evacuation shelter. Humans would have been streaming in from the fires.  It may not have been unsanitary lion conditions but other humans. After all those humans wore face masks to avoid the smoke, they really needed to avoid themselves.