My friend's 5yo, female, pitbull has recently started chewing up the lower branches of the pine trees on our property. She's also chewing the grape vines. She doesn't chew anything else in his house except a ball (I mean she's not chewing his shoes etc) but she'll spend a good half hour out there, just tearing up thick branches and actually eating them.
She's not chewing up stuff in the house, which would lead anyone to believe she needed stuff to chew. She comes outside to pee and whatnot, she plays fetch with her ball and while she is smelling around she ends up chewing these trees. This is a recent thing.
sorry, arwen, doc z emailed me earlier, but i've had a busy day, and haven't been able to get here.
dogs are pretty much stupid. and pitbulls are particularly so
no, really, i don't know. i do know that pine can be "toxic", or at least very irritating to the GI tract. (that being said, i've never seen a dog with pine toxicity).
my rottie mix tore all of the branches off of the lower quarter of my parents' pine tree- so that his back JUST touched the bottom branches, and then he used the tree as a back scratcher for the rest of his life and never chewed it again.
harvey eats sticks all the time. i pretty much blame it on stupidity or a very low amusement threshold.
it's very difficult to over-exercise a pit, and i think most kinds of weird behavior can be fixed with more exercise (it's been true for harvey, and my sister's and friends' pits, anyway).
maybe she just likes the taste?
sorry, no good answer for you. i'm going to go back to "dogs are just dumb"