Salmon poisoning disease in two Malayan sun bears

Area of Science:

• Veterinary Medicine
• Parasitology
• Wildlife Health

Background:

• Salmon poisoning disease (SPD) is caused by the rickettsial organism Neorickettsia helminthoeca.
• The disease is transmitted by the trematode Nanophyetus salmincola, often found in salmonid fish.
• Exotic captive animals, like sun bears, are susceptible to SPD.

Observation:

• Two captive sun bears (Helarctos malayanus) presented with acute vomiting, diarrhea, lethargy, and anorexia.
• Clinical signs appeared one week after consuming live trout from a northern California reservoir.
• Diagnostic findings included anemia, eosinophilia, lymphopenia, hypoalbuminemia, elevated GGT, ascites, mesenteric lymphadenopathy, and gastrointestinal inflammation.

Findings:

• Ova of Nanophyetus salmincola were identified in fecal samples from both bears.
• Histopathology confirmed lymphoplasmacytic and eosinophilic gastritis, enteritis, and colitis.
• Treatment with oxytetracycline, doxycycline, praziquantel, and famotidine resulted in rapid clinical improvement within one week.

Implications:

• Early diagnosis and appropriate treatment of SPD are crucial for successful recovery in susceptible species.
• Veterinarians should consider SPD in captive exotic animals, particularly bears, that consume raw fish, even outside endemic areas.
• Translocation of infected fish for sport fishing can expand the geographic range of SPD, necessitating heightened awareness and preparedness among veterinary professionals.