My Lab bitch is only just over 21" she is off trialing stock which is also worked hard by keepers, which makes her light built and fast.
I did all the usuall training until she was 7 months, i then stopped all dummy training and started light rough shooting, all a young lab wants to do is retrieve, but the only way my bitch got a retreive was if she hunted hard and made the fluch for me to shoot.
I dont know if this made her keener ( i guess alot was already in her) but she hits cover like a self harmer and when i get complements off lurcher lads when i use her bushing i know she is the busi