PKD
Parasitic
🟠 Severe
Proliferative Kidney Disease
🦠 Tetracapsuloides bryosalmonae · Buddenbrockiidae (Myxozoa)
📋 Definition
A myxozoan kidney disease of salmonids causing massive proliferation of lymphocytes and monocytes in the kidney, linked to climate warming and increased summer water temperatures.
📊 Key Facts
Causative Agent
Tetracapsuloides bryosalmonae
Agent Family
Buddenbrockiidae (Myxozoa)
Geographic Range
North America, Europe (salmonid rivers)
Transmission Routes
Waterborne (spores from bryozoan intermediate hosts)
Primary Host
Wild salmonids (brown trout most affected), rainbow trout
Vaccine
✗ None / Experimental
🩺 Clinical Signs
Swollen abdomen (grossly enlarged kidney), dark colouration, exophthalmia, emaciation, anaemia, impaired osmoregulation.
🔬 Symptoms
🔬
Grossly swollen kidney/abdomen
Renal Chronic
🔬
Emaciation
Systemic Chronic
🔬
Exophthalmia
Ophthalmic Subacute
🔬
Anaemia
Circulatory Chronic
🧪 Diagnosis
Histopathology (renal enlargement, PKX cells), PCR.
💊 Treatment
⚠️ No universally approved treatment is currently available. The information below covers supportive care and experimental approaches.
No effective treatment. Fumagillin suppresses development but is not licensed.
🛡️ Prevention
ℹ️ Prevention is the most effective strategy for managing this disease in aquaculture and aquarium settings.
Avoid exposing fish to infected rivers at temperatures >15°C. Rearing fish above bryozoan-containing reaches.