In past years, before we knew anything of SIDS, if a dead infant was found and there happened to be a cat nearby then the cat got the blame. Keep in mind that a cat is extremely unlikely to suffocate a baby. Most cats dislike the smell of human breath so it’s not the milk or formula, what cat would like that anyway.
You know how curious cats can be and they may want to investigate a new baby. They will probably be curious and probably somewhat wary of the new and noisy arrival so don’t panic when he sniffs the crib or hangs around. Many cats soon lose interest and look for entertainment elsewhere. Some become self-appointed guardians to the new arrival and will want to watch you as you care for the baby. The warmth of a crib, with baby in residence or not, is attractive to cats though they usually stay away from a baby’s face.
Keep the nursery door closed or fit a screen door when baby is asleep, but make sure Puss is not accidentally shut inside the nursery. If the nursery is at ground level or accessible from a roof or wall, keep the nursery windows closed or fit mesh screens. This precaution will keep cats – including strays and neighbors’ cats – from entering from outdoors. A baby alarm or intercom will allow you to monitor baby.
Babies may have traces of milk around their mouths and a cat may try to lick it off however, if baby is drinking formula not so much. But it is extremely unlikely that a cat would harm a baby, let alone suffocate it.
Remember that it is not recommended that cats and babies sleep together!