I hate avocado. The reason why birds never eat avocados is because it is deadly poisonous to birds - that’s the tree’s defence. The Guatemalan variety, which is the main one sold in the UK, is particularly poisonous. It’s a substance called persin that kills them.
Persin is a fat soluble fungicide that leaches into the fruit from the seed. It kills rabbits, and makes many domestic animals ill, plus horses, cows, pigs and presumably any animals in the wild that eat it. In rabbits they die due to cardiac arrhythmia, the other animals get mastitis and bowel problems. Never ever allow your dog or cat to eat any avocado, or the skin, you’ll have a house full of poo and vets bills.
It’s allegedly considered safe for humans, though as it is fat soluble, you won’t wee it out. Don’t know where it goes.
Anyway, it’s cytotoxic, so they are trying to make an additive from Persin to go with Tamoxifen in breast cancer.
All toxic substances have an LD50 - the dose that kills half the population. It’s usually tested on animals. I can’t find an LD50 for persin, presumably because it kills every animal they test it on.
But don’t mind me, enjoy your avocados. I, along with most of the animal kingdom, don’t think it is food. I’m not pushing my luck eating cytotoxic chemicals, thank you very much.