What arw the signs and symptoms of avian flu?
Clinical Signs
The severity of the disease ranges from inapparent (mild) to rapidly fatal. Lethal strains of the virus can strike so quickly, particularly in young chickens, that there may be no clinical signs other than sudden death.
Avian influenza viruses of low to moderate pathogenicity are identified regularly in the United States in the domestic poultry populations. Avian influenza virus is reintroduced into domestic poultry by migratory waterfowl, which are carriers of the influenza virus.
Clinical signs vary greatly and depend on many factors including the age and species of poultry affected, husbandry practices, and the inherent pathogenicity of the influenza virus strain. Clinical signs may include:
- ruffled feathers
- soft-shelled eggs
- depression and droopiness
- sudden drop in egg production
- loss of appetite
- cyanosis (purplish-blue coloring) of wattles and comb
- edema and swelling of head, eyelids, comb, wattles, and hocks
- diarrhea
- blood-tinged discharge from nostrils
- incoordination, including loss of ability to walk and stand
- pin-point hemorrhages (most easily seen on the feet and shanks)
- respiratory distress
- increased death losses in a flock
The clinical signs of avian influenza are similar to those of other avian diseases. Avian influenza may be confused with infectious bronchitis, infectious laryngotracheitis, fowl cholera, and the various forms of Newcastle disease.
Typical history, signs, and lesions may be suggestive of mild forms of avian influenza. Confirmation of a diagnosis is by serologic testing and virus isolation and identification. Because virulent strains of avian influenza are considered to be exotic to the United States, they are reportable to the USDA. Virulence level is evaluated by virus isolation and controlled laboratory challenge of experimental chickens.
http://edis.ifas.ufl.edu/ps032