“Leave it” is a very helpful command for any dog, and it’s easily taught even to nervous dogs - you do need to find something small and superbly delicious that they adore, however. Try cooked warm chicken, for eg, or a nice smelly cheese.
We learnt this at Luciano’s puppy preschool, and really wish we’d learnt it earlier. There are many ways to train this “swap” or “leave it” behaviour, but this one worked so incredibly fast, it was amazing.
Basic concept
Put the same excellent treat into both hands.
Close your hands into loose fists, palm side down.
Offer one fist to your dog; keep the other loosely off to the side.
Your dog should start pawing at your fist, trying to get to the treat.
Start saying “leave it … leave it … leave it”. This is one of the few times you keep repeating a training phrase.
Eventually, your dog will realise it’s not getting the treat, and stop in some way. It might be a turn of the head, or putting the paw down, or even walking away.
The instant that happens, say “good!” and immediately supply the treat in the OTHER hand, palm open. Don’t make them work for that treat.
Repeat from step 1.
It seems to only take about 10mins for a dog to realise that they won’t get the treat in the first hand, but by ignoring that treat, they’ll get the one in the second.
Once you’re at this stage, you can start encouraging your dog to move away from the desirable thing. This is utterly invaluable when you want them to back away from - say - a hole in the fence, or something dead, or an antique bone that everyone wants to play with.
You can try to use it to encourage them away from a live thing that they want to investigate it, but you may have limited success. Keep working at it, but remember that Maremmas have curiosity as part of their makeup, and if something moves, they want to check it out.
Set up a standard “leave it”.
Put the “treating” hand far enough away that your dog needs to step away from the “ignore” hand to get their treat.
Say “leave it” but only reward when they step away from the “ignore” hand and over over to the “treat” hand.
Keep increasing the distance between the “ignore” hand and the treat.
If you can get another person involved, even better. Ostentatiously hand the treat to that person; they reward the dog when it steps over to them on “leave it”.
Or try putting the “desirable thing” in something static, and put yourself a few steps away from it.
“Give me”
Once at this stage, you can try it when your dog has something in their mouth that you want. Try “leave it” and offer a treat in the usual hand that provides the treat. If you’re very lucky, they’ll immediately drop the thing in their mouth and take the treat.
You can use “leave it” still, or train to a different command if you feel you need “leave it” and “give me” as separate actions.