not-c-diff

Also seemingly involved is a species of Clostridium, which does have a wikipedia page:

https://en.wikipedia.org/wiki/Clostridium_perfringens

It's mentioned that some dogs showed a presence of both microbes. Maybe it's a harmful interaction between two different bacterial loads, that evolves into a toxic conflict, as each organism tries to kill off the rival population and colonize the environment for themselves?

That the toxin is canine specific is interesting. The contagion incubates for maybe three days before the dog is incapacitated by digestive problems, so you get the sense that after crossing the fecal/oral disease vector (spoiled food, sniffing and licking biofilm surfaces, tracking in vomit/feces contaminated soil after walking dog paths mutually shared by infected animals or carriers) the foreign bacteria might react to quorum sensing once it's gained a foothold in the hospitable gut environment that meets it's needs as a microbe.

Some signal in the canine metabolism sends it into overdrive and it blows up causing tissue damage, and then the animal's body tries to evict everything by retching and dumping out both ends.