Arthritis in ducks. II. Condemnation rate, economic significance and possible preventive measures.

During the period 1959 to 1968 0.4% of ducks slaughtered in Denmark were condemned because they had arthritis. The condemnation rate due to arthritis decreased 2 years after compulsory measures to control salmonella infections were introduced and in the 10 years from 1969 to 1978 this condemnation rate was 0.12%. The condemnation rate due to arthritis was relatively high during the period 1961 to 1967. A positive correlation between the condemnation rate due to arthritis and the number of ducks slaughtered and the overall condemnation rate existed at this time. Seasonal variations in the condemnation rate due to arthritis were observed. Mallards were found to be less susceptible to arthritis than White Pekin and Muscovy ducks reared under the same conditions. The hock was most frequently affected (43%) with arthritis. In 37% of arthritic birds the knee was affected, hip and toe joints being affected in 18% and 1% of cases respectively. Wing joints were affected in less than 1% of cases. The national annual cost of arthritis from 1959-1968 was estimated at 207, 579 Danish crowns. In the subsequent 10 years the cost was only one third of this sum.