Ours is collie/grey x deer/grey, and just checked my diaries, 5 months 25", 8 months 26 1/2, 10 months 27 1/2 and 13 months when she finished growing in height, a shade under 29". Again, as has probably been said, all pups grow at different rates and some, even from same litter, keep growing for a little while longer than some of their siblings, so yours could possibly grow on til 12-13 months