I had my first rat pup born with defect today. I kept back 2 females from 2 litters born early december. One (russian blue berk) was from a daughter-father breeding, the "daughter" came from the father being bred to a half sister(they shared the same father). The other (PEW) female came from the same male to his half sister.

Both the females were first time moms and bred to an unrelated capped himilayan male., the blue berk had 5 live babies, the PEW had 6, and one died shortly after birth(defect).

I'll try to post pictures of it tonight but it was missing its lower jaw, and didnt have defined nostrils, just a smal "hole" between where they should have been. Anyone seen a pup like that before? Is there a genetic component or was this just a fluke? The other 10 babies are fine, and the two litters before(their mothers) of 24 pups were from the same male and also healthy. Wondering if i should be culling this female and her offspring? Wasn't planning on keeping her as a breeder but i didn't have any other females to chose from.