Another example would be King Charles Spaniels, which are overbred to have tiny heads and big cute eyes - and are at high risk of seizures from compression of the brain by the skull :-(
I have shepherds and there's a big philosophical split between shepherd owners who want 'working line' dogs and those who want 'show dogs' that are significantly more likely to have health problems. Dog breeding is a very poorly regulated market and the outcomes are just as depressing as you would imagine.
It's easy to breed and sell dogs and hard to regulate/litigate against bad breeders. The US Kennel club prioritizes promoting 'breed standards' over the wellbeing of the animal. My informal observations suggest an overlap between such priorities and the general belief in animals as property/divinely ordained for human use/lacking in consciousness of any kind.
No engineering required, but obviously a huge change.