Mortimer is a finicky eater. Being a show dog, Mortimer eats gourmet dog food, premium dog food. It may not be human food, to Mortimer, its better!!!
Once he leaves Fred, there is no more premium dog food to be had. Farm fields and parking lots don’t have premium dog food available.
Wild dachshunds aren’t picky about what they eat. Here is a link from Arew.org You’ll be surprised at the answer.
Pickup a copy of Mortimer’s Odyssey at Barnes and Noble