My Golden is 5 years old and has a history of scratching himself down to the bloody skin. The vets always say food allergies. He has been eating Hills ZD Ultra hypoallergy food now for 4 months and he still is scratching.
A friend had luck with something called Derma Cap? Does anyone have experience with an Omega 3 and 6 supplement for itching in dogs? And would a human Omega supplement be good to give him?

It can't hurt omega is beneficial for people and dogs and has no side effects.
Can't say it will get rid of his itch since that could be a number of things but it should make his skin softer.

Have you considered doing a sensitivity test to detemine exactly what your dog is allergic to? I wouldn't do it in the general case, but if the allergy is severe, you might be better off knowing exactly what it is.

I have gone to a California Natural Diet, didn't stop the scratching completely, but made a HUGE difference!

Since corn oil is relatively cheap, most dog chows contain enough of it or similar oils to provide more than enough of the essential fatty acids to keep a dog's coat in good shape. There may be a few dogs that will do better with a little more. A teaspoon a day of liquid cooking oil will do the same thing for much less than the supplements.

If the dog really has food allergies, nothing is going to work except a chow without the allergens. Doing blood work to identify the specific ones is expensive. In many cases the vet will do like yours, and try a few chows less likely to a problem.

I know that Flint River Ranch Pet Food is very digestible and most dog owners who use this (including me) for their dogs who have food allergies do quite well on it. It does not contain a lot of the extra ingredients that dog's don't need that can cause these problems. My Jack Russell has a very sensitive stomach and I tried everything under the sun and this works the best for her.

Flint River Ranch Super Premium Cat Food and Dog Food