One of the first signs of illness for a cockatiel is a change in weight. Unfortunately, most pet owners are unaware of this and do not own a scale or check weight on a regular basis.

Birds naturally mask illness. By the time we notice that they are sick they are often very ill. Catch illness sooner by observing loss in weight.

A cockatiel usually weighs:
70 to 125 grams (according to Margaret A. Wissman, DVM on the BirdChannel.com)

My birds are 78 grams and 104 grams. Depending on where you got your birds from you can expect some variety.

Slow weight loss (a few grams) over a few days may indicate illness.
When I see 10% weight loss I start to get worried and I seek veterinary help.
The first cockatiel I had lost 20% by the time I realized he was sick and was too ill for treatment to succeed.

When shopping for a scale, remember that the resolution must be at least 1.0 gram. Some food scales are sufficient. However, it is convenient if the scale comes with a bird perch. You mayPurchase A Bird Scale Here.