拥有一只斗牛犬有多大的风险？ 我不是在谈论致命事件，而是咬伤，因为咬伤仍然是一个不好的结果，任何咬人的狗都应该被安乐死。 如果我们考虑一只狗咬伤其主人的年风险，针对斗牛犬和金毛寻回犬进行规模化，并推算30年……

How do you calculate this? Simple. First, we need estimates of the portion of the U.S. population bitten by dogs per year. Next, to adjust that, we need the portion of those bites that are to owners. So, for overall dogs, we get about 1.5% and roughly ~25% of that. Then, to obtain lifetime risk figures, we need to pick a length for a 'lifetime'. I picked thirty years because that's what I picked. Sue me. It's about three dog lifetimes. P(>=1 bite) = 1-(1-p)^t It's pure probability math. To rescale for the breed, we need estimates of the relative risk of different dog being the perpetrators of bites. We'll use the NYC DOHMH's 2015-22 figures to get the risk for a Golden Retriever (breed = "Retriever" in the dataset) relative to all other dogs, and Lee et al. 2021's figures to get the risk for a pit bull. The results don't change much just using the NYC figures, they just became significantly higher risk for the pit bulls. To rescale 'p' for b reed, it's just p_{breed} = p_{baseline} \times RR_{breed}. Then you plug it back into the probability of a bite within thirty years. If you think, say, pit bulls are undercounted for the denominator for their RR, OK! Then let's take that to the limit and say that every 'Black' neighborhood in New York has one, halve the risk noticed for them, and bam, you still get 1-in-5 to 1-in-2.5 owners getting bit in the time they own pit bulls (30 years). And mind you, bites are not nips. As Ira Glass had to be informed when he was talking about his notorious pit bull, it did not just "nip" two children, it drew blood, and that makes it a bite. Final method note: the lower-bound for Golden Retriever risk was calculated out as 0.00131%, but that rounded down to 0. Over a typical pet dog lifespan of 10-13 years, an individual Golden Retriever will almost-certainly not bite its owner even once, whereas a given pit that lives 11.5 years will have an 18-33% chance of biting, and if we use the DOHMH RRs, it's much higher. If we use the DOHMH RR and double their population, that still holds. The very high risk of a bite associated with a pit bull is highly robust and defies the notion that '99.XXXX% won't ever hurt anyone.' The idea that almost no pit bulls are bad is based on total fatality risk and it is a farcical argument on par with claiming that Great White Sharks shouldn't be avoided because they kill so few people. Frankly, if we throw in non-owner risk, the typical pit bull *will* hurt some human or some animal over a typical pet dog's lifespan. And because pit bulls live a little bit shorter, you can adjust that down, but the result will still directionally hold because they are just that god-awful of a breed. Final note: Any dog that attacks a human or another dog that wasn't actively attacking them first should be put down. That is a big part of why this matters. These attacks indicate that the dogs in question must die.