I have a singleton puppy born by c section  .Mum is rejecting puppy ..advice on getting pup to feed please

Two pairs of hands of you can, hold mum down and latch the pup on. Stay with them at all times. The more she feeds, the sooner instinct will kick in.  I had a litter born by c section and it took a full 12 hours for instincts to kick in, mum then started cleaning the pups, tried to chew cords etc as though they had just been born. I had to cover her eyes whilst holding her in position.  It’s hard work at first but so worth it.

Having had quite a number of C.Sections, we have NEVER had a Sectioned bitch who couldn't be persuaded to nurse their puppy/puppies.   Even with singleton litters.   As suggested, you need to get your bitch to lie down while talking gently with her, and latch the puppy/puppies on.   With a full sized litter, just put one or two on at first - which obviously doesn't apply here.  

I was lucky with a litter of 9 puppies I had.   Having had a C.Section although she walked out of the vet's office, by the time we got home, barely 10 mins. later, she'd zonked out so I managed to carry her indoors (a dead weight!) and to the whelping box, switch on the brood lamp (this was 24 December with ice/snow on the ground) and go back to the car for the box with the puppies in.   In the middle of all that, the agent who'd sold us the property (we moved in on Dec 6) arrived with a Christmas bottle.  I'm afraid he got short shrift, poor man but I think he realised the situation - it was very much a farming area.   Because mum was zonked out, I managed to latch on all the puppies, although has to be said, they'd been with her at the vet's office when I arrived - yoiks.   My husband had to go to work for half a day, and wasn't there.

You might, and this is yuck, put some of her discharge on the puppy, which might help her to recognise that this strange creature belongs to her and allow instinct to kick in.   If it's at all possible, the puppy needs mum's first milk to protect him through the first 5 weeks or so.   So if it's at all possible to get her to allow him to nurse, do it.    Don't leave her alone with the puppy until she has accepted him.

How long ago did she whelp? It's quite normal for c section pups and mums to take a while longer to bond. Everything has been affected.

Firstly you need to make sure the pup gets collostrum, whatever you do with the mum. You might need to have someone feed her food continuously in a down stay or even muzzle her and hold her still whilst pup nurses, but pup really has to get that collostrum. It has lifelong benefits in terms of health.

Assuming pup has got collostrum, supervise very closely further feedings and do similar if necessary. Try not to move to bottle feeding - use mum's milk only if possible so you can at least give her a few days for maternal impulses to kick in.

It is best to bring home some amniotic fluid and MESS from the vets and to smear that on the pup. Mum smells it on the pup and recognises her smell and her stuff and realises the pup is also hers. Is it possible to get some of that, even if you just have some bloody towels lying around from some part of whelping that you can smear on the pup for mum to lick off? If mum has any discharge when she wees you can also mop some of that up on a towel and put it on the pup...

Some people even put a dab of peanut butter on the pup, to encourage mum to lick, but bodily fluids are better if available.

Give it time as well, hormones change relatively slowly...

With ours I would have to put the pup on her and I would sit and stroke my girl. Luckily she was just not that interested in being with her pup but was fine when told to go feed him or he was brought out to her so I didn't have to hold her there.
You may need to hold her until she gets better.