4 Feline - I'd never had any like those two.

I did have a female with kittens who came to me when the kittens were 8 hrs. old and the mom took a dislike to one of the kittens. The vet said he was healthy and normal (except for his horrible loud annoying meow that got on EVERYONE'S nerves...), so we kept tricking the mom into nursing him. We'd put vanilla on her nose so she couldn't smell him (and prayed he'd keep his mouth shut!), would rearrange the kittens to make sure he got a good nipple, even supplemented her nursing with replacement. As soon as this mama cat would realize which one he was, she'd take him out of the playpen and dump him in another part of the house, usually near another cat I had who looked similar to that mom (he never could smell the difference and she'd wallop him sending him sliding across the floor).

Although he never lost the annoying meow, he lived for many years after his mother was put to sleep. After his two brothers and a sister were adopted, I accepted a foster cat who'd tested neg. for FeLV/FIV, but turned out to be FIP positive. This mother tested positive right away, but this guy was 2nd to the last to die - about 6 years later.

We never knew what it was about him that the mother had found so objectionable, unless it was that meow - reminded me of what it would sound like if you stepped on a siamese's tail.