Good morning,Our 8 month old Cocker Alfie has developed a habit of digging holes in the garden to get at the shingle the lawn was laid on to help with the drainage.
The shingle is around 5"to 6" below the surface so he has to dig a big hole to get at it.Luckily the garden is big enougn for us to have given him his own fenced off garden so the main lawn is safe it just looks like the army had gone through blowing everything up leaving mini craters all over the place. My concern is that he may been eating the shingle and if he is the damage he may be doing to himself(slighty paranoid as we lost Ollie at 2yrs due to huge kidney stones not, a related issue i know but the word stones and Cockers fills me with dred.)
Any help or advice would be much appreciated.

My own experience is that I lost a Cocker Spaniel at around 9 months and when they opened him up, he was full of small stones and pebbles - we hadn't even seen him eating them :-( It had caused damage to his gut and intestines. So, I think you're right to be concerned.

No advice but just to say my dog is a terror for stones - it has got better - I try to make sure she has something else to chew on in the garden if she is out there for a while and not just sunning herself.  Trouble is we have all those decorative pieces of slate edging the paving - it is a horror - the grandchildren play with it too - scattering it all over the place (and putting it into their mouths given half a chance.  I really didn't want it in my new garden - but I just got laughed at - how else are we going to make the garden look nice our builder says.  My dog took a pebble out of a plant pot once and went over to my OH who made a fuss of her while it was in her mouth - I saw her swallow.  Luckily the next day she ate and ate grass until she vomited it back up.  

we taught our boy the drop command, basically just for good manners, but it was lucky we did beacuse he developed a love of really small pebbles. if we werent quick enough in stopping him he'd eat them.
we are so glad we did. he now drops anything when instructed, including his favourite food, wafer thin ham...
i moan about him too much, i love my border collie :-D (but wouldn't have another :-) )

London my Bernese Mountain Dog has learned the 'spit it out' command ;) so everytime I see him chewing something that I don't know of I say 'spit it out' and he does hahaha!! so funny :) so I sugest you to start training him something like that, you have no idea how much dogs can learn ;)

My mums male pug used to eat small stones, not something you want to encourage obviously! They passed through him, thankfully.

She used to shake an empty bottle with stones in (ironic, eh? lol ;-) ) to suprise him into stopping when she caught him at it. It took a while but it seemed to do the trick. You could also try the water squirting trick too, no good if he doesnt mind water though!

I think you'll just have to watch him like a hawk and try and distact him when he starts to dig for the pebbles.