Have you ever wondered why cats and dogs are born blind but other animals are able to open their eyes and even walk after birth?
A great deal of animals across the natural world are blind when they are born, ranging from rodents to birds – and the experience can last as long as a few months. In mammals such as rabbits, horses, dogs, and cats, this usually involves the eyes still being fused together at birth. The reason for this all comes down to different birthing strategies and can get quite complicated but has a basic root in evolution. Animals will give birth to their young at different stages of life depending on life history.
Cats and dogs are born this way because their mothers have short pregnancies, or gestation periods, meaning the babies are born in a partially developed state.
This is an evolutionary trade-off; the young are more at risk when they are born blind and helpless, but their mother is more likely to survive the pregnancy and birth, and therefore be around to look after them when they need her most. Dogs, for instance, only have a gestation period of around two months. At the other extreme, cows have a gestation period of nine month; the young are born fully developed and can walk within minutes. The choice between these two types of reproduction is influenced by the animal’s behaviour; for dogs, pregnancy is dangerous because the females are less able to hunt, whereas for cows, being able to run from birth is essential for keeping up with the herd and escaping predators.