Red Dwarf

Marooned - S3-E2

Question: Why was there dog food on board in the first place? I thought that Red Dwarf wasn't meant to have any animals on board- so why was it needed?

Chosen answer: It's entirely possible there were animals on board. Lister mentions lab mice, there could have been other lab animals too, or pets. Lister got in trouble with the cat because it hadn't been quarentined or vacinated.