If it is raw chicken bones are not that big of a deal, particularly if it is shop=bought (as opposed to organically raised) chicken. The problem with chicken bones is that when they are cooked they tend to splinter in to sharp shards, but raw, and not organic, the odds are the poor little things will have grown so rapidyly their bones will still be very soft and quite safe for animals to eat. I feed Shadow chicken carcases for his teeth and likewise the cats get chicken wings. They eat the lot ...
He looks as if he is having a great time - I say let him go for it.
BTW> The vet I used to work for mentioned on more than one occasion that since KFC had opened in the neighbourhood (that was back when they were a rarity) there had been no increase in cats choking on bones. Considering the number of discarded cartons with bones, and the number of pet cats allowed to roam at night, I think that is a fair indication of the level of risk.
Also when that particular point of view was established, chicken was eaten after they had slowed down laying (i.e. around 4 years old) - i have the recipe books to prove it. These days they are slaughtered around 16 weeks, which makes a considerable diffference to the toughness of their bones. Let him enjoy himself, I say.
