Making decisions together

I got to thinking about making decisions together, with your spouse or partner. I recently overheard a phone conversation in which a husband was stupefied to hear that his wife had adopted a dog… much to his dismay and without his consent. He told her he was very upset and wouldn’t be walking the dog EVER. I can’t say I blame him. Not that I don’t want a dog, I love dogs dearly, but I wouldn’t want my partner to make that decision without me. Isn’t that a decision you make together? Shouldn’t you lean on your partner? Is it a partnership without agreement and deciding things together? Is it ever okay to make a huge life decision without consulting your partner? Is getting a dog without consent grounds for divorce? What would you do? How would you deal with it?