I think as long as it’s introduced slowly it should be fine.

I don’t think they mean for you to totally replace the hay though – they need the hay for digestion.

I think it’s also just a suggestion, not a guarantee.

Here is the full paragraph:

7) “Any rabbit that does not wear its teeth sufficiently will end up with its mouth held open by elongated cheek and/or incisor teeth. This interferes with chewing, and once established the problem tends to self perpetuate.” Crossley made the point that the chewing of fresh grass probably tends to abrade the teeth even better than the chewing of hay. Needless to say, however, in many areas of the USA, chewing grass outdoors will expose the rabbit to life-threatening diseases such as Baylisascaris, West Nile virus, etc. etc. – so hay may be the overall best choice for those who don’t have protected “grazing land” for their house rabbits. In any case, the overall thrust of his lecture was this: Feed your rabbit low-energy, high-silicate vegetation that will require hours (literally) of chewing. The way to keep your bunny’s GI tract healthy turns out also to be the way to keep his teeth healthy.

http://www.vrra.org/dental.htm

Here’s the link to the article..interesing article.

I think it’s very interesting what the vet says about how pellets are chewed as opposed to hay/grass.

Worth reading the whole article.

Horses taken from hay to grass can end up with colic or founder etc-so your totally on the right track introducing it slowly and not taking it out completely! I found mine wouldn’t touch grass at all at first but then really liked it