>>78705765Known fact: There is a "rage plague" afflicting city dwellers and turning them into feral animalistic critters.
Supposition: It is contagious. Supported by otter-attacks-panther, and later a feral panther.
Supposition: Someone is doing this to people on purpose.
Which brings us to: Who benefits?
My guess is that someone disagrees with the idea of Zootopia on racial or quasi-religious grounds and is trying to get the city to break up into species-specific districts instead of being a melting pot. If the virus, or whatever, can only move cross species, so an otter can infect a panther but not another otter, the result would be species segregation once people knew what was happening.