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SD Viral 🟡 Moderate 🔔 OIE Notifiable 💉 Vaccine Available

Sleeping Disease

🦠 Sleeping disease virus (SDV / Salmonid alphavirus 2) · Togaviridae

📋 Overview

SD is the freshwater counterpart of Salmon Pancreas Disease (caused by SAV1 and SAV3 in seawater). The virus targets pancreatic acinar cells and cardiac muscle, causing progressive necrosis. Survivor fish may grow poorly and remain persistent carriers.

📊 Key Facts

Causative Agent
Sleeping disease virus (SDV / Salmonid alphavirus 2)
Agent Family
Togaviridae
Genome Type
ssRNA, positive-sense
Peak Mortality
40%
Onset to Peak
2–4 weeks
Geographic Range
Europe (France, UK, Italy, Poland)
Transmission Routes
Water-borne, horizontal fish-to-fish
Primary Host
Rainbow Trout (Oncorhynchus mykiss) in freshwater
Treatment
⚠ Supportive only
Vaccine
✓ Available
First Described
1995

🩺 Clinical Signs

Fish lying on side at bottom, reduced feeding, fin necrosis, pancreatic exocrine necrosis, cardiomyopathy.

🔬 Symptoms

🔬
Lying on side at bottom
Neurological Acute
🔬
Anorexia
Digestive Acute
🔬
Fin necrosis
Integumentary Subacute
🔬
Pancreatic necrosis
Digestive Acute

🧪 Diagnosis

RT-PCR, virus isolation (CHSE-214, BF-2 cells), histopathology.

💊 Treatment

ℹ️ Treatment options are supportive. Consult a qualified fish health professional.
Supportive; improving water quality, reducing stocking density.

🛡️ Prevention

ℹ️ Prevention is the most effective strategy for managing this disease in aquaculture and aquarium settings.
Certified disease-free eggs, vaccination, biosecurity.