Adding Oil For Itchy Skin

Corn oil is extremely high in Omega 6 fatty acids, which are absolutely necessary for healthy skin, BUT most dog foods have PLENTY. You may see it listed as linoleic acid. They're also quite shelf stable, so if your food says 3% linoleic acid, it most likely has 3% linoleic acid when your dog consumes it.
 
Salmon oil is very high in Omega 3 fatty acids. They're needed in a ratio of between 1:10 and 1:1 with Omega 6 (that is, between 1 part Omega 3 and 10 arts Omega 6, to one part of each. I aim for closer to 1:1, but that may or may not be beneficial. I'd say 4:1 is probably the most used ratio), but the trick is Omega 3's are NOT shelf stable in dog foods, so what it says on the bag probably isn't what's in the food by the time puppers eat it. Many foods don't even contain many Omega 3's.
 
Corn oil might help if you're feeding a really cheap grocery brand, but if you're feeding a decent brand, it most likely won't, but salmon oil probably would.

Thanks for the great response! I am feeding Eagle Pack Holistic, LG & giant puppy food. So I guess I should stick with the salmon oil. I have heard of Grizzly oil, any better suggestions..or is this one good? How much would you add to each feeding, or would you give once a day? He is 12 weeks,19 Lbs. I was told to feed 2 1/2 to 3 cups a day. I am only feeding 2 cups, in 2 feedings.

Grizzly's fine, especially if it's what you can find locally, but if you're ordering it, you might want to go with "pharmaceutical grade", also called molecularly distilled, which is ultra-filtered so it has no toxins or heavy metals. Timberwolf Organics [linkhttp://www.timberwolforganics.com/s.nl/sc.7/.f]salmon oil[/link] is pharmaceutical grade, as is [linkhttp://www.icelandpure.com/salmon_oil_info.htm]Iceland Pure[/link], and [linkhttp://www.onlynaturalpet.com/products/Only-Natural-Pet-Salmon-Oil/999060.aspx]Only Natural Pet's[/link]. I'm sure others are too, but those are the ones I know of. I'm using Nature's Logic's [linkhttp://natureslogic.com/products/saroil.html]sardine oil[/link] right now. It's not pharm. grade, but sardines have much lower levels of toxins and metals anyway, and I just figured I'd try it since Cherokee'd been on salmon oil for so long. So far so good.

Oh, and I'm not sure how much to give a puppy. I would guess just follow the bottle's amounts based on weight, but you might want to give more to a pup. Maybe someone else can answer that. The amount will be per day, so you can either split that in half and give half per feeding, or give it all at once. I don't think it matters. And I'm not sure if you've heard this, but you generally want to supplement vitamin E when adding oils. Again, I don't know about puppies, maybe you shouldn't for them.

My first thought on Corn oil is that yes it is cheap but i would think not very digestable either,and as chelsea mentioned it is an omega6(inactivated form!) which most dogs get in excess anyhow.

I would be interested to hear why this nutritionist recommended something like corn oil,instead of fish oil etc??

I would not give corn oil to itchy dogs. Corn is often an allergy problem. Have you seen a dermatologist to find the problem?