What is the main cause of skin allergies in dogs?

My dog has skin allergies, and I'm not sure what causes it. We give her omega 3s, and benydryl, and that seems to help. I'm just wondering what causes it and it's year round too.

What is the main cause of skin allergies in dogs?
My dog has skin probs.I changed his diet to include fresh veg he likes celery and carrots because they need veg just like humans lots of people only feed meat. Also grass can cause allergic reactions but you cant really keep them off so you just have to feed them well and treat any allergies they have with grass as best you can.
Reply:uhh grass normally
Reply:Sometimes it is grass or other weeds. It can be anything from the laundrey detergent you use(because they touch your clothes) to the shampoo you bath them with. It is hard to tell. 2 of my dogs have allergies, but it is to things in the air, which causes them to have athsma attacks.
Reply:For our golden, it's FOOD, namely grains. That means no kibble. For more information, check out RawDog Canada. We've been feeding her a modified raw diet, and avoiding all grains, dairy and eggs for the last 5.5 years, and she's had very few hotspots and ear infections. If the skin itchiness is mainly on your dog's feet and legs, it's probably environmental - something she's touching. If the itchiness happens only in the summer, it could be mosquito or flea bite sensitivity. Ours gets that too. My biggest help was from other dog owners, who'd been there. My vet confirmed that it WAS food allergies, but his only suggestion was prednizone shots and yet another kind of kibble. Good luck to you in your search for help.
Reply:Fleas
Reply:Have her thyroid checked. Sometimes when the thyroid acts up, they will get itchy skin, loose hair, sores from scratching, hot spots, etc. I do not know what breed you have but some, like my shelties, has it run in some of the lines. It is a simple blood test (one version is the Michigan Panel) that does not really cost much (usually around $50) but if that is what it is, there is medication that can be given to stop the symptoms and normalize the thyroid hormones.