Influenza A virus subtype H5N8
H5N8 is a subtype of the Influenza A virus (sometimes called bird flu virus). Although H5N8 is considered one of the lower pathogenic subtypes, it is beginning to become more so. Many times, H5N8 is used as an incubator for the highly pathogenic H1N1. 
For the most part, symptoms of the H5N8 virus are respiratory. The common symptoms are "flu-like": fever, chills, headache, coughing, and weakness. Conjunctivitis reportedly has been associated with the virus, as well. When farmed poultry are confirmed as having the virus, the farm will cull the birds. This way, the virus will hopefully not be passed along to the public. However, neighboring farms and area wildlife must be tested, also.
Perhaps the most known outbreak of H5N8 occurred in Ireland in 1983. Poultry on two farms showed the usual symptoms, plus diarrhea, nervousness, and depression. Poultry farms within close proximity soon began to show signs of infection, as well, but no contact between the farms could be established. In the end, 8,000 turkeys, 28,020 chickens, and 270,000 ducks were culled. When investigated in the lab, clinical findings demonstrated that turkeys were the most susceptible to infection. The virus could not be clinically reproduced in ducks.