Had my first death of grooming client, an elderly Border terrier. She must have gone downhill quite quickly, she was about 13 but still pretty lively when I groomed her 3 weeks ago. I didn't know whether I should send a card, like some vets do?

If my dogs were professionally groomed I would be so pleased that you thought of me at such a sad time. Especially if I'd been going for some time.

Always.  If it's true, then I'd say what a pleasure they were to groom, how much I'll miss seeing them too and hope that the owner will keep in touch.  By leaving the door open like that I would often have owners ask me to help them find another puppy/dog and then I could steer them away from bybs. :)
If they weren't a pleasure to me (very few weren't!) then I'd just say that I'm sure they'll leave a big gap in the owners lives. :)

What a lovely thought, I would be touched to receive one.

If you want to send one, and I think you do, do it.  Don't make it a business decision.  They will appreciate it I am sure and know it is a genuine offer of condolence. 

I would send one I'm sure the owner will appreciate it

what a lovely thought--the owner will be so touched.

Oh good, I'll do that - thanks all. :-) I doubt she'll be looking for another as she's pretty elderly and is housebound, but you never know.

Oh please do.....
It's an emotional thing to get condolence cards from the vet, but it would be even more precious to get one from someone else who knew the dog.

Maybe if she does contact you, it would be nice to steer her in the direction of an older rescue dog?

Older dogs for older people is a great solution for both. :)  And groomers involved with their local dog community are well placed to match both. I've done it many times with perfect outcomes. :) :)

I've also invited my older clients with no dogs around for a cuppa so that they can share my dogs for an hour.  To me it was all part of the service. :)

definitley send one and maybe a copy of the Rainbow Bridge too. If I recieve one yes it would b make  me cry but I would also be touched by your thoughts