Salmon poisoning disease in dogs: clinical presentation, diagnosis and treatment

Salmon poisoning disease (SPD) is caused by a rickettsial organism, Neorickettsia helminthoeca, that is carried by the trematode Nanophyetus salmincola, which encysts in freshwater fish, most commonly salmonids. We reported two dogs from the United States West Coast that had similar clinical signs, hematologic and biochemistry findings. They were both diagnosed with salmon poisoning disease. Lymph node cytology showed morula formation, suggestive of N. helminthoeca organisms in macrophages, while the parasitological fecal test found ova of N. salmincola. The dogs were treated early and showed complete remission of clinical signs within a few days. Lymph node cytology and fecal parasitology are quick and low-cost tests that can be performed whenever SPD is suspected. SPD should be considered as a differential diagnosis for a canine patient with clinical signs of vomiting, diarrhea, lethargy, and lymphadenomegaly; laboratory findings of thrombocytopenia and hypoalbuminemia; and potential exposure to raw fish from the West Coast of the US or Southern Brazil. The earlier the diagnosis and treatment, the greater the chance of survival.