Not all insurance companies will want to issue you a Homeowners Insurance policy when you have a Pit Bull since Pit Bulls are more prone to attack and bite people so some insurance companies will not want to take on the liability of your Pit Bull and may not want to cover you.
It's not impossible though to get Homeowners Insurance when you have a Pit Bull but you can expect to pay a higher price for your Homeowners Insurance policy if you do get insured and have a Pit Bull.