Salmon Poisoning Disease in Dogs

N. helminthoeca is a species of bacteria that causes salmon poisoning disease in dogs. The bacteria is carried by parasitic flatworms from the Nanophyetus family, which are found in native to the Pacific northwest. Dogs, and other canines, become infected by ingesting the raw fish.

The bacteria is carried by certain kinds of fish, including:

• Salmon
• Trout
• Sculpin
• Sturgeon
• Candlefish
• Lamprey

Salmon poisoning disease is a potentially life-threatening infectious disease requiring prompt veterinary assessment.

If treated hastily, dogs usually improve within 2 to 3 days from the start of antibiotic treatment and are able to recover completely. If the condition is left untreated, most affected animals die five to fourteen days from ingestion.

Any dog with access to raw fish sourced from the Pacific northwest is at risk of salmon poisoning disease. Very young, very old, and immunocompromised individuals are at highest risk of developing severe disease. Dogs living in endemic areas who are able to roam freely on the coast and those working for fisheries on the Pacific coast are at highest risk of exposure. Dogs on raw, fish-based diets are also at risk.

Elokomin fluke fever (EFF) is a condition that resembles salmon poisoning disease, caused by N. elokominica bacteria. EFF can infect a broader range of animal species, including canines, ferrets, raccoons, and bears. EFF has a lower death rate than SPD, with only 10% of infected animals dying due to untreated N. elokominica infections. Symptoms of EFF are less severe and occur later (14 days to a month after ingestion) than those of SPD.

Salmon poisoning disease (SPD), also known as fish disease, is caused by the Neorickettsia helminthoeca bacteria. The bacteria is carried by parasitic flatworms that live in fish native to the Pacific northwest.

Once infected fish are ingested, the infected flatworms implant in the intestine, and the bacteria enter the bloodstream, spreading to several organs and causing SPD.

Main symptoms of salmon poisoning disease develop five to seven days after ingestion of the infected fish.

Ongoing diarrhea may lead to dehydration.

Initial diagnosis of SPD is based on the presence of symptoms, history of exposure, and geographic location. Diagnostic tools include:

• Physical examination
• Bloodwork
• Urinalysis
• Diagnostic imaging such as ultrasound
• Fecal examination
• Lymph node biopsy
• Analysis of intestinal contents
• Specific testing for the bacteria where available

Dogs diagnosed with SPD frequently require hospitalization. Treatment options include:

• IV fluid therapy to treat and prevent severe dehydration
• Antibiotic treatment
• Blood transfusions
• Supportive care for vomiting and diarrhea

Cases with early treatment and diagnosis usually improve within 2 to 3 days and are able to recover completely. Left untreated, SPD usually leads to death within weeks of ingestion of infected fish.

The only way to prevent SPD is to ensure that pets do not ingest raw fish from the Pacific Northwest. Neorickettsia bacteria are easily eliminated by freezing (2 weeks minimum) or cooking infected fish. Prevention strategies include:

• Keeping dogs on a leash while at the beach
• Proper disposal of fish entrails
• Not feeding raw fish to animals

Only dogs that ingest raw salmon, trout, or steelhead from the pacific northwest are susceptible to developing SPD and EFF.

• IV fluid therapy
• Antibiotic treatment Blood transfusions
• Supportive care