
I remember asking my mentor to teach me how to palpate for pups, I was so glad I did because I thought that like humans the uterine horns would grow from the vulva up, I learnt that the horns fill up from the ribs down, she said there is a very small window around 3 weeks when the pups are the size of a kidney bean[ may be bigger in larger breeds] and can be counted, after that there is too much fluid around the pups to be able to palpate each pup, in the coming weeks not all the pups will survive for varying reasons so final count may be less than the number at 3 weeks.
I have never managed to palpate pups despite being a midwife and examining hundreds of women, during a teaching session with a consultant I was the only one to diagnose that this patient was having triplets, others had come up with twins but no one picked up on the third baby lying horizontally up by her ribs,she went on to have 3 healthy babies on Xmas Eve 1981, 2 boys and a girl at 34 weeks by normal delivery and they went home 4 weeks later.