What am I doing wrong? Are they sick?

[Sid Post]

I have Welsh Harlequin ducklings. They look fine and healthy and are very active. Last night I had 5 of 11 die. They have good water and plenty of feed. I can't see any sickness. They are are on dry clean wood shavings with a heat lamp up high in a 4'x4' brooder and are four weeks old.

TIA,
Sid

 

[Amiga]

What is the temperature? Do they leave the brooder?

I would take them for a necropsy.

What has changed?

 

[Sid Post]

Ambient temperatures is ~85F, no huddling and, they don't hang out or avoid the heat lamp. Humidity is pretty high with frequent intermittent light rain, though they are in the garage away from the chicks (~20'). They brooder is closed so they can't leave without my help.

There have been no significant changes recently.

 

[Amiga]

Keep at least one refrigerated (around that temperature), in hopes you can get a necropsy done to find out what is wrong.

This time of year, if a mosquito carrying certain protozoans bites them, it could be fatal.

 

[Sid Post]

Thanks!