Salmon poisoning disease (SPD) has been identified in the Pacific NW down through northern California. Because of the name, most people think of it as some sort of food poisoning obtained by eating bad salmon. The organism responsible for SPD is actually a small microscopic (rickettsial) organism located within the immature form of a fluke that colonizes the flesh of salmon. If raw fish are ingested by dogs, the fluke will mature within the intestine and release the rickettsial organism that causes disease.
Symptoms usually occur within five to seven days of ingestion of infected fish and may include fever up to 104F, vomiting, diarrhea, loss of appetite and weakness. The body’s lymph nodes are usually enlarged and can be palpated on exam. Diagnosis is often made by identifying the fluke eggs on a fecal exam, but a CBC/chemistry, abdominal x-rays or ultrasound should be performed to rule out any concurrent diseases.
Patients are generally hospitalized for aggressive supportive care due to rapid onset of symptoms. Diarrhea and vomiting can be severe or become bloody, so fluid support is required. Medications include a tetracycline antibiotic to eradicate the rickettsial organism as well as a general deworming medication to treat for the flukes. If SPD is caught early and treated appropriately, the prognosis is good and patients usually recovery fully.