The debate to dock, or not to dock, will always be ongoing. Some countries don’t dock at all.
In the US, a Vizsla’s tail is docked 1/3 of its length. In other words the tail that remains is 2/3 the length. This is longer than other sporting breed dogs.
My personal take is that if the dog is damaging its tail on a continuous basis, I would dock the tail.
It may put a dog out of competition, as it may not conform to a breed standard for each country.
All of my dog’s tails have been docked to US, AKC, conformation standards. None of them have suffered from the docking, and I’ve never had a tail injury.
At the end of the day, it is your dog, and you have to decide what it right for it.