Chewing dried up apple cores?

[Carrotsandcelery]

Tonight my dog has started to chew on old dried up apple cores from the flower bed. They are as dry as a stick would be.

He doesn't chew sticks however, or even dog chews, as he was kicked about the head by his previous owner and has a sensitive jaw as a result

Is it safe for him to do this? Why would he suddenly start to do this? These are apples which fell in the autumn and have mostly been eaten by the birds.

Can anyone shed some light?

I read somewhere they are not good as the seeds contain arsenic but I'm not sure how many they would need to eat to cause a problem.

Thanks Betti - I have got him inside and shut the door as I am a bit concerned. It also occurred to me that the apple could have fermented a bit - I don't fancy a drunk dog