Kane turns 14 weeks this Friday, and is already on the last hole of his 16" collar. I was going to order him a new one, but wasn't sure whay size to go to. Should I order his soon to be "adult collar" and use it now. Hes 4 months, 40 lbs, and growing like a damn weed! I'm going to update pics in the morning when I am home from work. Thanks ahead of time for any info.