Ulcer disease in common carp fisheries in the UK

Ulcer disease (or carp erythrodermatitis) associated with atypical Aeromonas salmonicida was diagnosed in two common carp fisheries in England. Managers from these two fisheries reported mortality rates over 30%. Clinical signs in fish included severe dropsy, exophthalmia, and varying sizes of skin ulcers. Fish were not systemically infected with atypical A. salmonicida; however, the bacteria was isolated from ulcers. Mortality was suspected to be due to osmoregulatory failure. Treatment options for this condition in fisheries are limited due to the extensive nature of these operations and, therefore, managers may want to focus on prevention strategies. Preventing stress on fish and improving water quality should help reduce the risk of this condition.