Do as I say not as I do!

For the last couple of days I have been very short with my dad. He doesn't understand why. He gets a wild hair and just does what ever he wants. He went out and bought another dog. There is nothing wrong with having dogs, I have two myself.
The problem is, is that it's my grandmas house. Yes he lives there and has built on to her house so now some of the house is his. But it's still her house. She hates dogs, and inside animals. My dad keeps buying dogs and it makes her a nervous wreck. So I haven't been very kind to him.The last time he got a dog, it was a border collie she destroyed the yard. Now he went and got another border collie. I just think that he is in the wrong and he is going to keep justifying to himself until he feels good about the bad decision he has made. What ever happened to respecting your elders! I can remember when I was living at the house, I had brought a dog home and they blew up at me. They even had my brother come down and tell me that I needed to respect the rules. So tell me What is the difference. in this situation? As I talked to him today I told him that he was showing a lack of respect for my grandma. That is just how I feel. He should wait until he has the house all to himself and then get as many animals as he wants. I know my mom reads my blog and so please don't copy this for dad to read. He would be so so mad. I love him to death, but he needs to learn that he can't just do what he wants and be in a bad mood until he gets it.