Definition of whirling disease in US English:

whirling disease


  • A disease of juvenile trout and salmon caused by a parasitic protozoan, affecting the balance of the fish and causing it to swim with a whirling motion.

    The protozoan is Myxobolus cerebralis, phylum Sporozoa

    • ‘In yet another controversy, the new EPA chief's family fish farm stands accused of introducing trout infected with the deadly whirling disease - which causes fish to swim in circles - into Utah rivers.’
    • ‘In some rivers whirling disease causes little harm to fish, but it can also suddenly erupt, causing a so-called ‘hot zone’ in which thousands of young fish die.’