Winter Ulcer
Moritella viscosa
Animal model: Atlantic salmon
Applications: Vaccines, functional feeds, repellents, physical barriers, environmental treatments, system modification, immersion and in feed treatments, benchmarking commercial treatments, genetic selection/ phenotyping
Type of model: Immersion, Intraperitoneal (IP)
Clinical Signs of Disease in our Model: Cutaneous lesions which develop to sub cutaneous ulcerative lesions with skeletal muscle exposed, typically large and on a single flank
Challenge conditions: 25-35ppt, 3-12C
Other end points: Semi-quantitative pathological scoring, periodic sampling
Starting Fish Size: 50 g - 2 kg
Summary:
The bacterium Moritella viscosa is the autological agent of winter ulcer disease. Typically, infection and associated pathogenesis are of the highest risk in colder water temperatures (<8°C), though the pathogen is often isolated at warmer temperatures as well. The disease has a classical presentation of large ulcerative skin lesion(s) which are subcutaneous which can cause the skeletal muscle to be exposed. Field outbreaks can result in high mortality, though most often the disease presentation is chronic leading to economic and animal welfare concerns. Chronically affected animals may be moribund, show reduced growth, and are of poor harvest quality. The disease challenge models developed at CAT have been designed to simulate farm outbreaks and can be manipulated to cause acute or chronic pathogenesis and mortality. The model is frequently used to test the efficacy of several novel feed, vaccine, and other technologies, as well as to benchmark existing commercial treatments.
