Dangers of breeding
Breeding animals is not always easy, many breeders can tell you their bad experiences. Almost every experienced breeder has been in a difficult situation once or twice. Kittens can die, females can become seriously ill or they might even die at a young age. Luckily, this does not happen often, but please bear in mind that every pregnancy is a risk for both the female and her kittens.
Dangers to the mother
Like mentioned above sometimes fatal complications occur during the pregnancy or delivery. The mother can get problems when one of the kittens is too big and it gets stuck in the birth canal. It can also happen that one of the uterus horns gets twisted (called uterine torsion), so that the kittens cannot be delivered, and the mother as well as the kittens will die if the problem is not recognized quickly enough by the vet. Eclampsia can develop before or after the delivery which increases the risk of the mother and/or the kittens to not survive this. Luckily in most cases everything goes all right, and these examples mentioned above are the exceptions.
Dangers to the kittens
The kittens can of course get ill too. This can vary from an occasional dirty eye to a bacterial infection with severe consequences. Next to that, kittens can get into problems while they are exploring the world. It would not be the first time a kitten bites through an electric wire and gets an electric shock. A small hole or chink behind furniture is also very interesting to a young kitten. It happens regularly that kittens crawl into these small spaces where they cannot escape from without help. Clumping litter can also be a danger to kittens. Kittens are just as curious as human babies, they put everything in their mouths and they want to taste everything. Clumping litter causes internal blockage with terrible consequences. Therefore it is better to use wood pellets or non-clumping litter as litter box filling for kittens.