I do not think Dobermanns (or any other breed) are "stubborn" but I DO think that you have to find a way into a dog's head. After all there have been WT Ch in Dobermanns and of course Schutzhund 3 and many compete successfully in Agility.

Training is simple.

As long as you remember two things.

1 Make it simple for the dog
2 Provide sufficient reward

Dogs do what works.

You might find this link useful


http://www.deesdogs.com/documents/wa...headhalter.pdf

Also, you may find that your dog is not happy with a head halter and you may have more luck with a harness such as the Halti Harness or the Mekuti one.

Good luck