Natural and Experimental Persistence of Highly Pathogenic H5 Influenza Viruses in Slurry of Domestic Ducks, with or without Lime Treatment.

Infections by A/H5 and A/H7 avian influenza viruses (AIVs) can cause acute disease and are therefore notifiable in poultry and wild birds. During winter 2015-2016, several cases of infection caused by highly pathogenic (HP) AIVs belonging to the A/H5N1, A/H5N2, and A/H5N9 subtypes were detected in southwestern France. Throughout winter 2016-2017, several cases of infections caused mainly by A/H5N8 HP AIV (A/goose/GD/1/1996, clade 2.

Congenital cataract in 1-day-old French Mulard ducklings.

Ocular opacity, associated with reluctance to move and inability to feed properly, was observed in approximately 1% of all newly hatched females from several related flocks of Mulard ducks. A 5-week follow-up study of 10 1-day-old affected females was performed, and they were compared with 10 control animals. Clinical, ocular and ultrasonographic examinations, and a complete necropsy of two animals per group with histological examination of the eye, were performed weekly.