How do I stop my gundogs squabbling?

One of my three gundogs is very possessive and is so eager to please that when I throw a ball she will either steal it or stop the other two dogs from retrieving it, leading to squabbling. How can I prevent this?

Should I send my gundog to a pro?

I have been training a young spaniel myself and although it's my first I feel that I have done a good job installing all the basic sit, stay, walk at heel and stopping on the whistle commands.

How do I stop my gun dogs from running ahead?

Gun dogs: When beating, I can’t stop my spaniel running ahead to the front of the wood before working back to the line of beaters. The walking guns love him for pushing game back to them but it’s a fault I want to cure. How do I go about it?…