Should i cut my dad off for what he said about my brother?

My brother has to put his dog down of 13 years a few days ago, because he was suffering from heart failure. He would give him medication 4 times a day. Leave work, wake up in the middle of the night. Take him to the vet repeatedly. I was talking to my brother. He said he's feeling a lot of guilt. I asked him why, and he said he feels like he could have done more. I assured him that he did all he could do, and even more than a lot of people would. I told my dad what my brother said to me, and all he said was "that's self pity". I was kind of in shock. He's said insensitive things in the past, like when I was depressed he told me I need to stop feeling sorry for my self, but this was a whole knew level. I don't know, I kind of feel like this is undeniable proof my dad is just a shitty person.