This is most definitely unusual behaviour considering the temperament of the standard Vizsla. It sounds like he's asserting his authority which is unacceptable but is a symptom of his environment. Herein lies the answer.
Being alpha, the leader, is an essential role in any dogs life. It makes for a stronger pack, a safer environment and a more successful family unit. This is core and very important considering the Vizsla is primarily a hunting dog. He sees your husband as the boss and he probably sees the rest of the family as his siblings who need to be kept in check. This is the wrong way around.
There are simple things you can do which makes a world of difference to him and his character will change accordingly.
[li]You eat your dinner, he waits until you've finished, then he eats his.[/li]
[li]You sit on the sofa, he sits on the floor.[/li]
[li]You walk in the house first, he enters the house last.[/li]
[li]On walks, you greet other dogs first, establish a bond, then introduce your dog to the other.[/li]
[li]The weaker of the pack (ie. the smaller kids) must assert authority over toys. The dog must wait to be given them before playing with them.[/li]
Can you see the pattern? He's asserting himself because he feels he has to. Vizsla's are beautiful dogs and it's very easy to be "coochy" with them and let them run around doing as they please but they are very powerful animals with a strong hunting instinct and need discipline. All dogs should be at the very bottom of the chain of command in the home and early training certainly helps but all dogs need affirmation on their position in the home throughout their lives. When they don't have to rely on being the boss and worrying about the pack (ie. your family), they turn into affectionate, playful and loving pets.
All the best.