The bacteria's species does not have a wikipedia page yet, but here is the genus:
https://en.wikipedia.org/wiki/Providencia_(bacterium)
Meanwhile, a Google search for "Seasonal Canine Illness" produced mixed results, none of which says much about digestive problems, upset stomach or incontinence within the veterinary context.
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.
Unfortunately, not all the pathogens found in any or many of the cases will be causative. Some pathogens or newer strains thereof may be harder to detect.
To make matters worse, some of the dogs with the same symptoms won't even have the same disease.
The common dog cold? Dog flu?
What kind of seasonal outbreak affects dogs?