I have a 7month old male springer.  He lives with a golden retriever aged 3 yrs and a greyhound aged 10.  He is fine with the retriever (they play fight but get on well) and the greyhound bitch ignores him. 

We take the dogs for walks in the country and the springer is great off a lead, only problem is if he sees other dogs.  He wants to chase and bite them (not play fighting).  We have scolded him, put him on a lead when he does not behave etc.

Apart from that, he is a lovely dog.  Just need some ideas.

Why is he off lead if he wont behave?  This dog is looking for a serious butt whipping and some dog, some day, will give it to him.  :-)

The vet has suggested that he stay off his lead when in the country, so that he can socialise with other dogs.  It was suggested that when the dog is on a lead he fears other dogs and this will make him worst.

I also have a Springer who unfortunatly had discovered this sort of 'game' before I got her :(  Yes, she is also fearful when on lead, but I worked with a 'watch me' command when around other dogs, so she ignores them pretty much now. Allowing him off lead to repeat the unwanted behaviour time and time again is not socialisation.

If a dog is onlead, it CAN'T chase other dogs, and freedom has to be earnt, it is NOT a right :(  Scolding him when he comes back is not going to help his recall, and he may also be associating your stress with the presence of other dogs, so it becomes a viscious circle - dog chases other dogs, owner gets cross, dog associates presence of other dogs with owners stress, so works harder to keep other dogs away :(

I think you need somebody experienced who can watch him 'in action' to deduce what is going on between his ears, and advice accordingly.