Duck vitamin B 2 deficiency is a kind of nutritional and metabolic disease, which is caused by the deficiency of vitamin B 2 in ducklings. It is characterized by slow growth, web-clawed feet curled to rat race and paralysis, it is common in clinic. Clinical symptoms and pathological changes, clinical symptoms: Slow Growth and development of sick ducks, emaciation, curly feathers, disheveled dull, diarrhea, decreased appetite. 

The severely ill duck's webbed feet curl inward, making it extremely difficult to walk, often landing at hock joints, the leg muscles atrophy, the skin is dry and rough, and eventually die of exhaustion. 

The symptoms of the disease in adult ducks were decreased egg production and fertilization rate, thin egg white such as water, light yolk color, increased dead embryo at late hatching stage, decreased hatchling rate and more weak chicks. 

Weak ducklings can be shown as foot paralysis, tufts like curly. PATHOLOGICAL CHANGES: Dead ducklings malnutrition, atrophy of gastrointestinal Mucosa, intestinal tract filled with foam-like content, leg muscle relaxation, atrophy. 

Diagnosis method: through the analysis of duck feed and the course of disease, combined with the characteristic clinical symptoms, the diagnosis can be made.

Prevention: The disease can be prevented by adding yeast, green feed and fish meal which are rich in vitamin B 2 to the feed of ducks and ensuring sufficient vitamin B 2 in the feed. After the ducks were infected, the formula of feed should be adjusted in time and vitamin B 20.5-1 g should be added according to 50 kg feed for 7-10 days. For obvious symptoms of sick ducks, can use vitamin B 2 injection or oral, each 2-3 mg, continuous 3-4 days.