Flat chested kitten syndrome (FCKS) and pectus excavatum (PE)
Uncommonly, kittens will be born with, or develop in the first few weeks of life, deformities of the wall of the chest (thorax). The result of the deformity can be to reduce the space for the lungs and affect the blood circulation. The severity of the deformity is very variable so its effects can range from nothing to severe difficulties breathing and oxygenating the blood. Severely affected kittens may not survive.