An excess number of seeds would have tobe chewed and ingested to reach toxic levels. We used to have apple trees in our horse pasture, and the horses ate all the apples with no ill effects.
I don't bother to remove seeds when feeding apples to the rabbits - there aren't enough seeds to cause any harm.
Very small amounts of cyanide are acritical part of the rabbit's (and human)diet and are synthesized in the form ofvitamin B12 (cyanocobalamin).
Many types of foods given to our rabbits actually contain low levels of cyanide including flaxseed, linseed, millet, soy, spinach, corn, some types of grasses (Johnson, Sudan, Trefoil), and cherry leaves. Cassavaroot - notoriously known for high cyanide levels,is also fed to rabbits in many countries.
Gorging on excess amounts of cyanide containing foodscan be dangerous (as well as a rabbit gorging itself on any type of food), but small amounts of cyanidein feeds is not harmful.
Pam