It depends - it depends on what the dog is doing, what the home's occupants are doing (trying to flee, trying to contain the dog, encouraging the dog to attack). If the dog made any "threatening" moves towards to the officers, they would, under most circumstances, be considered justified in using deadly force to stop the dog.
If you're thinking that a "large aggressive" dog will stop the police from executing the warrant you are very much mistaken. And if you think that the police shooting and killing the dog in the process is going to make the dog's owner rich, you are also mistaken.
They would shoot it.
A large agressive dog is a lethal threat against them and a distraction from other potential lethal threats. It will not prevent the house from being searched.
Law enforcement agencies know why people have large agressive dogs. Having one will put an extra layer of suspicion on whatever is in the warrant.
The Dog Whisperer has enough money and business. Get a bassett hound.