I am so sorry to hear about Kiwi.... Its so heartbreaking, but you may very well not have mistakenly given a seed, that cover that sticks with the apple where the seeds grow can be a problem. When you cut the apple, you may have cut a seed without ever knowing it. I am so so sorry....
Lisa - apple seeds contain a cyanide... in large quantities they are dangerous to humans.
Your best best with birds is to get one of those goofy animal corers, it takes the center out completely. Just toss the center to always be safe. Even when I use that when we have apple and peanut butter (a favorite non gluten snack for me), I still use a paring knife and take the thin edge of each slice off to make sure non of that harder pocket from the seeds is left.
Taking a moment to state what most of probably know, but just to be safe and repeat.... no apple seeds, no chocolate, no avocados in any form, no onions,... those are the major toxins that we very commonly have in our homes. There are lots and lots of others be careful or avoid food lists, take a moment and do a quick search on the forms. Just figured I'd type the obvious...
