Ok. I had an article on my blog about liability insurance for dog bites, I received an email asking what companies will be good for aggressive dogs. That's all I know. I guess the answer is - Call the home insurance companies in your state.
The person who sent you the email probably had a specific situation, a certain state, a certain dog, and knew if the dog had a history of attacks. With that information, it can be answered. Without it, its almost impossible to answer the question.
In general, if a dog has a history of attacks, it will be difficult to write, and the dog will likely be excluded.
If the breed has a history of attacks, many insurers either won't write the policy, or exclude the dog (I have no idea if this is the majority).
If the dog has no history, but is an aggressive breed, some insurers will write the house, with the dog, until the first bite, then the dog will be excluded.
I can't answer specifically without a specific question.
Dan