I have been told that a GSD bitch has lost her litter and the owners were told by the vet that it was due to be mated twice?? I understand that the bitch was taken away by the stud dog owner and brought back the next day.
I've searched the Internet and come across superfoetation & superfecundation. I understand the information I've read but wondered if anyone else had had this problem?

Never heard of it but most bitches are mated twice if possible, sounds an unlikely problem. I'm sure the experts will be on soon!

Most bitches have a minimum of 2 matings.  Unless there is some misunderstanding in what was said, this doesn't sound like a reasonable assumption to me.
My experience is that Vets, unless involved in breeding themselves, know very little about mating, whelping and weaning pups.  Their expertise is in unzipping, if necessary.

"Their expertise is in unzipping" :D :D
To be fair, I'm constantly amazed by what people think their vet said.

This happened with one of my girls. She had one pup naturally and the others she needed a c-section for, they were definitely younger than the male that was born.

It has been known for vets to deliver pups from totally different fathers that definitely look different ages! 

I must admit though, this has only happened to me once and I still believe in mating more than once.

Which is why I am trying to give the Vet the benefit of the doubt! :rolleyes: ;)

the unzipping vet you mean val :)

>I'm constantly amazed by what people think their vet said. 

Exactly :) I've said before that I've often felt I would love to hear what the vet's recollection of a consultation was ;)
I not too convinced that the average vet knows little about breeding and whelping etc.  In the last few decades dog breeding has shifted from large kennels, very experienced in these matters, willing and capable of dealing with many difficulties encountered without veterinary intervention to many, many small hobby breeders.  You only have to buy a catalogue at a local show to see how many breeders reside in a small area to realise that most vets will have several on their patch.  It seems to me that these breeders are far more likely to involve their vets at looking at healthy normal pregnancies for reassurance and for dealing with fairly straightforward deliveries than was ever the case in the past.

lots of good points in that post Isabel ....I am very lucky to have a vet who says when all is well leave her alone...the thing thats gets me thinking is when a litter say is born and the owner think pups are from 2 or more matings ( with same dog) due to the size it makes me wonder how this can be ?? if a bitch ovulates between 24 and 48 hrs only ........... as if they ovulated for up to 5 days or more there not be so many bitches who miss when mated at the wrong time

I would think it jolly difficult to say with any certainty why any pup would vary in size as there must be several possibilities.  The uterus in a dog in a rather long affair so differences of blood supply to whelps seems entirely possible to me, the quality of the placenta for another or just simple genetic differences.

Well my bitch had 4 matings with 7 days between the first and last matings, out of the littyer (6) only one was smaller than the rest, they were all good weights between 9.5-10.8 with the littlest one being 7.7 BUT she is alot finer and lighter framed than the rest but I don't think she is particularly "younger" than the rest. She was mated on days 10,12,15 &17 and whelped 62 days from day 15, maiden bitch. I don't think she was ready on days 10 & 12 but she was awkward so my breeder advised mating her then, I thought she was ready days 15 & 17 hence me taking her back.