There will always be more of a chance of a dog getting worms through raw than through kibble.

The reason is simple: kibble doesn't have worms; raw may.

That said, your dog is in the dirt, all-day, every day, and there is a thousand percent greater chance that your dog is going to get worms just digging and amusing himself all day than there is from him getting worms eating raw, human-grade meat. You can also reduce the minimal chance of worms in raw meat by freezing the meat ... and there really isn't much of a chance at all with chicken.

Finally, with simple monthly worming, if you use the right stuff, the issue of worms is not much of an issue, really.

Hope this clarifies,

Jack