Our 5 year old cocker ran off yesterday in Battersea Park.  My husband was walking her and passed a couple of professional dog walkers who had a fairly large pack of dogs.  By the time he had realised she was missing she was nowhere to be seen.  She has been off the lead for 4 and a half years in this particular park with nothing like this happening.  After searching high and low for her my husband returned to the car to see if she had made her own way there and fortunately she was waiting by the side of it.  Is this something to be concerned about in the future?  We are obviously wary about letting her off the lead now.  She has never been afraid of larger packs of dogs and on the occassion an aggressive dog has attacked her or our other dog (or my husband on one occassion!) she has always fought back.  Could this just be a one-off?  or would it be sensible to keep her on her lead for a couple of days?  We don't always take the car to the park and I dread to think of her trying to get accross the busy roads along the Embankment to make her way home.  I would be grateful for any thoughts.
Thank you. 

For the time being I would go back to using a long line and seeing if any thing else spooks her. Not a flexi as if you drop it the sound of the handle falling might spook her more. Start retraining recalls and using high rewards like sausage or small pieces of liver to get her attention. Good luck.

Glad you found your dog. It happened to me a few months ago in a much smaller park than Battersea, and I was in bits by the time we were reunited. I use a horse lunge rein if I think he might be tempted to go hunting rabbits, which was why he went AWOL in the first place.