Salmon poisoning is often a fatal disease caused by ingestion of raw fish infected with Neorickettsia helminthoeca parasite.
The poisoning, however, doesn't come from the parasite itself but from the bacteria which infects it.
It used to be accepted that if a dog was infected, treated with antibiotics and recovered, they'd become immune to future poisoning. It was also believed that problem was mostly a concern in the Pacific Northwest.
Now, things might have gotten more complicated.
Researchers at Oregon State University have identified another bacterium, SF agent, found in Stellanchasmus falcatus fluke, that can cause symptoms similar to "salmon poisoning". This bacterium can be found anywhere in the world. It also throws the idea of acquired immunity out the window.
Without treatment, 90 percent of dogs can die in a week to 10 days.
Source article:
Discovery of new bacteria complicates problem with salmon poisoning in dogs