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07:57
Necropsy-based Wild Fish Health Assessment
Published on: September 11, 2018
Steatitis in egrets and herons from Japan
Yasuko Neagari1, Suzue Arii, Mai Udagawa
1Laboratory for Intellectual Fundamentals for Environmental Studies, National Institute for Environmental Studies, Onogawa 16-2, Tsukuba City, Ibaraki Prefecture, 305-8506, Japan. neagari.yasuko@nies.go.jp
Journal of Wildlife Diseases
|January 29, 2011
Summary
Over 70 wild birds in Japan died from steatitis, a condition linked to low vitamin E levels and cyanobacteria blooms in their water source. This outbreak highlights a significant wildlife health concern.
Area of Science:
- Avian pathology
- Wildlife toxicology
- Environmental health
Background:
- Steatitis, characterized by inflammation of adipose tissue, is typically seen in captive animals.
- A large die-off of egrets and herons occurred in a Japanese reservoir.
- Affected birds exhibited severe weakness and inability to fly.
Purpose of the Study:
- To investigate the cause of a steatitis outbreak in wild birds in Japan.
- To determine the contributing environmental factors and pathological findings.
Main Methods:
- Necropsy and histopathological examination of affected birds.
- Analysis of blood vitamin E levels.
- Water quality testing for cyanobacteria and microcystins.
Main Results:
- Diagnosis of steatitis confirmed through gross lesions and histopathology.
- Low blood vitamin E levels were observed in affected egrets.
- High counts of cyanobacteria (Microcystis aeruginosa) were present in the reservoir, but no microcystins were detected.
Conclusions:
- This is the first reported case of steatitis in wild birds in Japan.
- Cyanobacteria blooms and low vitamin E may be associated with the outbreak.
- Further research is needed to understand the specific mechanisms and environmental triggers.
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