Long story, but bitch mated 3 1/2 weeks ago has been scratching and chewing her rump. Found one flea. Anal glands also quite full (been emptied).

Vet suggested putting Stronghold on her as said this is safe. I'm not really happy about that.

Any suggestions for what I can safely use on her please?

Frontline SPRAY not spot on.

I wouldn't be happy about Stronghold.  But I have used the Stronghold SPRAY as Barbara advises.

One hot summer I found a single solitary flea on a pregnant bitch.  Blasted it with the spray so hard, I'm sure I drowned the little bugger.  It is the only thing I would recommend as, knowing my bitch had an event free pregnancy, and normal whelping, I have to go with tried and tested.  :-)

> I found a single solitary flea on a pregnant bitch

If I thought it was a solitary flea I would be inclined to remove it, destroy it and wait and see. 

Too late to edit my post!  :-(

Apologies - I meant the same treatment as Barbara.  Frontline spray.  My mistake.

You can use Frontline spot on on a pregnant bitch but not on young puppies.
I've never used any of the other products around but I think the spray you can use on pups from 2 weeks is it? With veterinary advice as the spray is prescription only I believe. As is the Frontline Combo.

Thanks for your replies. So far we have removed it and destroyed it (obviously LOL) and used a flea comb on her. Also used flea comb on other dogs and cat. I have a breed that is susceptible to auto immune problems so do not like spot ons at the best of times.

I've never used the Frontline spray before but have very occasionally used the spot on. All the dogs have garlic and fenugreek regularly and I don't usually have a problem.

Update to help others...

Used the frontline spray and all stopped chewing within a day.

Good news on bitch, 7 healthy puppies of good weight.

Congrats on the new arrivals.

Thanks, they all have homes when they are old enough :)