Why should you not give dogs apple cores what do the pips do

Apple cores are perfectly safe, unless you plan to give your dog about 100 at once! Apple pips contain a miniscule amount of cyanide, but not nearly enough to do any harm at all in normal quantities.

My concern would not be the natural toxic content, which as Jeangenie says is insignificant, but the toxic residue of pesticides such as Carbendazim, used worldwide, which do collect in the seed. Carbenazim is a known carcinogen and also affect chromosomes. Have a look at the Pesticide Action Network website www.pan-uk.org

And a cautionary note from chemistry.about.com:

<<If you accidentally eat a cherry pit in a pie or swallow an apple seed or two, you'll be fine. Actually, if you swallow several seeds whole, you would absorb a minimal amount of the toxic compounds. Chewing the seeds makes them much more hazardous to your health. Children and pets are much more likely to suffer poisoning from eating the seeds than adults>>

Be on the safer side and buy organic for people and pets.