
Herman is a 10 month old LH Weimaraner. Up to now his recall has been good anywhere we go - he is an utter mummys boy and didn't use to let me get out of sight on a walk.
In fact, his recall IS still pretty good - as long as there's no other dogs about. If a dog tells him no, he tries again and again and again..... If a dog runs then, as Hermans most favouritest game EVER is chase (he and the cat play it - it's quite a sight to see a big gangly puppy get chased by a furry Norwegian kitten

He seems to go deaf as soon as he spots another dog - it doesn't matter what noise I make, what I shout at him, what treat I have, whether I turn and walk the opposite way, nothing - he doesn't even acknowledge me.
To be fair, everyone has been fine with him - it is playing, there is no aggression - but 1. it's no fun seeing a big gangly dog come bounding up to you, blatently ignoring its owner, 2. Not all dogs are fine with it, one day he will get bitten. 3. It's dangerous having the complete lack of attention! and 4. It's just plain rude - I would be really cross if I had my dog out and this huge hairy thing came and started leaping about, especially if my dog was on a lead.
He isn't food or toy orientated in the slightest and he plays out with his friends 4 or 5 times a week. We go to puppy training weekly (I got told this selective deafness was a Weimy thing

I feel tomorrows offlead walk should be done on the lead if I can't trust him to recall, but he won't understand why he's on the lead when he's normally off, will he? Dogs (or boys, or boy dogs) don't do logical, sadly.
What to do, what to do?