Symptoms of HPAI in Waterfowl

Lethargy

Birds aren’t as active as normal, may seem reluctant to rise. They don’t forage as far as normal, or may tend to hide and isolate themselves from the flock.

lack of appetite

Birds don’t consume their usual amount of feed, and may stop eating entirely. Birds generally refuse even their favorite treats. We found that most (not all) would continue to drink if prompted.

Pale bill/legs

Especially in geese, the bills and legs became noticeably paler. The change was very sudden, and generally indicated death within 48 hours.

seizures

Seizures began in many ducks and were especially intense in the geese, usually hours prior to death. They may begin with head twitching or light shaking, then proceeded to full-body seizures. In all cases but one, birds exhibiting seizures died within 24 hours (usually within 12 hours).

lack of eggs

More than expected drop in egg production. This was the first symptom in our flock. We saw a 2-3 week decline in egg production to well below what we expected for the season. At the onset of other symptoms, the birds stopped laying completely.

eye/nose discharge

Some birds (less than 1/3) exhibited runny eyes or nose, sneezing, or coughing. Despite HPAI being a respiratory disease, this was not a reliable indicator of infection in our flock.

feather loss

This is one symptom we haven’t seen reported elsewhere - many of our seriously affected ducks began dropping feathers as though they were molting, even if they had already completed their annual molt. Feathers generally came from the abdomen (short body/down feathers, not wing primaries or other large feathers), and it seemed like they were loosening at the follicle. They were easily knocked loose even during gentle handling.