Salmon Poisoning (Anaplasmataceae)

Question 1

What agent causes salmon poisoning?

Answer 1

Gram negative, obligate intracellular bacteria

• Neorickettsia helminthoeca

Question 2

Which species is affected by salmon poisoning?

Answer 2

Dogs (also foxes, coyotes, raccoons, captive bears)

Question 3

Who is the intermediate host of salmon poisoning?

Answer 3

1st IH: aquatic snails

2nd IH: salmonid fish (“sick fish that Labradors lick”)

Question 4

How is salmon poisoning transmitted?

Answer 4

Flukes Nanophyetus salmincola (asymptomatic from fluke, sick from Neorickettsia)

Question 5

Where (geographically) is salmon poisoning seen?

Answer 5

Coastal regions

• Northern California, Oregon, Washington in the US and BC in Canada ONLY

Question 6

Who is the poster child for salmon poisoning?

Answer 6

Any age affected, but ~3 year old, male dogs (Labrador retrievers)

Question 7

What is the pathogenesis of salmon poisoning?

Answer 7

Neorickettsia replicates within macrophages > granulomatous inflammatory (macrophages, neutrophils) response within stomach, intestines, lymph nodes and spleen

• Incubation period: 2-14 days
• Severity of illness varies

Question 8

What are the clinical signs in a dog with salmon poisoning?

Answer 8

• Innapetence or anorexia (100%)
• Lethargy
• V/D
• Hematochezia
• Weight loss
• Melena
• PU/PD
• Peripheral lymphadenomegaly
• Fever, dehydration, abdominal pain, and more

Question 9

What are the laboratory abnormalities in a dog with salmon poisoning?

Answer 9

• CBC
  
  • Thrombocytopenia > will be 2-3X higher than immune mediated thrombocytopenia
  • Anemia > GI hemorrhage
  • Neutrophilia
• Chemistry
  
  • Hyponatremia
  • Hypokalemia
  • Hypoalbuminemia
  • Less common: increased liver enzymes, hypoglobulinemia and hypocholesterolemia
• Clotting function: DIC!

Question 10

How do you diagnose a dog with suspected salmon poisoning?

Answer 10

Clinical signs +

• Fecal sedimentation + zinc sulfate centrifugal flotation (fluke)
• Cytology (FNA of lymph node), PCR, or histopathology of biopsy or necropsy (Neorickettsia bacteria)
  
  • Lymph node, spleen, feces, blood

Question 11

How do you treat a dog with salmon poisoning?

Answer 11

Supportive care

• Fluids
  
  • Colloids vs. crystalloids
• Antinausea medication (Cerenia)

Neorickettsia helminthoeca: doxycycline, tetracycline or oxytetracycline (14 days)

Nanophyetus salmincola: dewormer (Praziquantal, Droncit)

Question 12

What is the prognosis for salmon poisoning?

Answer 12

Good outcome if treated early, but an alternate strain can result in reinfection again