North American Veterinary Licensing Examination (NAVLE) Practice Test

The organism responsible for causing salmon poisoning in dogs is Neorickettsia helminthoeca. This bacterium is an intracellular pathogen that infects dogs when they consume raw or undercooked salmon that is infected with the parasite Nanophyetus salmincola. The life cycle of Nanophyetus includes an aquatic snail as an intermediate host, and the salmon acts as a host where the parasite develops. When dogs ingest the infected salmon, Neorickettsia helminthoeca is released from the parasites in the gut and causes clinical illness, including signs like vomiting, diarrhea, fever, and potentially severe illness if untreated.

Understanding this relationship is crucial for recognizing how the consumption of certain types of fish can lead to specific health issues in dogs, emphasizing the importance of proper food handling and preparation. The other options, such as Nanophyetus salmincola, are involved in the life cycle but are not the direct causative agent of the illness itself. Oxytrema silicula is a type of snail, which is the intermediate host for Nanophyetus, and Rickettsia rickettsii is responsible for Rocky Mountain spotted fever, which is unrelated to salmon poisoning in dogs.