our cavalier keeps scratching at his neck (ears)

[ilovemarkb]

im worried that it could be Syringomyelia. just been looking at some images of it in the early stages. Had oscar to the vet numerous times last year for his repetitive scratching, but none of the treatments worked from the vet, we even changed his food. they never done any allergy testing. The scratching did subside between nov - feb but has got quite bad in the last few weeks. He groans as he scratches then ends up getting his claws stuck in his ear fur, i keep having to cut lots of cotters out. Any advice would be greatly appreciated. julie