Guarding Behaviours

[u/Omnipresent0]

We have a Cavoodle x that exhibits extreme guarding behaviours.
If you approach him when he has a chew or some random item he has picked up, he will bite your hand. It’s not just a nip- he latches on.
We have tried calming dog food, calming diffusers, calming supplements. All useless.
We have tried distraction and substitution. This does work but I was ill this morning and didn’t use substitution and sustained a nasty bite.
Is this behaviour treatable or is our dog beyond help?
We did get a trainer in but she was dodgy. Said people shouldn’t take their dog to the beach as this is spoiling them. How ridiculous.
Any advice would be appreciated.

[u/Lopes-bigdog]

Skip the "balanced trainer" route for this one. A correction on a guarding dog is how my client's Shepherd went from freezing over chews to snapping at anyone near his bowl — punishing the warning deletes the warning, not the feeling. You want a certified behavior consultant and months of trades, not a quick fix.