A dog that has recently traveled to British Columbia and presents with fever and diarrhea is likely suffering from what disease?

The scenario of a dog that has recently traveled to British Columbia and is now exhibiting symptoms of fever and diarrhea strongly supports the diagnosis of salmon poisoning. This disease is associated with the ingestion of raw fish, specifically salmon, which can harbor a parasite called Neorickettsia helmintheca. The presence of fever and gastrointestinal symptoms are typical clinical signs of salmon poisoning, and the geographic location is significant because this condition is particularly prevalent in Pacific Northwest regions, including British Columbia.

In contrast, the other diseases listed may have overlapping symptoms but do not correlate as strongly with the dog's recent travel or the specific clinical signs presented. For instance, leptospirosis can indeed cause fever and diarrhea, but it is not geographically specific to British Columbia and may have other risk factors associated with exposure to contaminated water. Parvovirus infection is a serious viral disease that typically presents with severe diarrhea and vomiting, but it is primarily seen in unvaccinated puppies or dogs with no prior exposure. Lastly, bacterial gastroenteritis can cause diarrhea and fever, but it often arises from various dietary indiscretions or bacterial infections without a specific link to travel or geographical exposure. Thus, salmon poisoning is the most likely diagnosis given the dog's recent history and clinical presentation.