Deworming Puppies and Kittens?

Question

Why do we deworm puppies and kittens that have healthy parents and have never been in any element that would lead to worms?

And why are there 2 doses?

Answer 1

this is because signs of worms dont always show up at first and if left too late can lead to diseases

even unborn puppies can have worms and can get them from mummy's milk

Answer 2

Because roundworms can enter a hypobiotic state (like hibernation) in the mammary glands of female dogs, and re-activate once she starts producing milk. This occurs if the female dog has had round worms at ANY stage of her life, even though she may be perfectly healthy and have no intestinal worms as an adult.

She produces milk, the pups drink it and become infected, worms grow up and start producing eggs which re-infect the dam and the pups again.

So we worm the pups a few weeks appart, the first time to kill any adult worms, and the second time to kill any worms that developed from eggs that the pups had picked up at or after the first dose. Piperazine (the common treatment) does not kill worm eggs, only the adults.