Organic Dog Foods in the UK are not as plentiful as you would expect they would be, but I have a couple of starting points for you.
One of the Organic Certification companies is the Organic Farmers and Growers and this link will take you there (opens new window) if you would like to obtain more information on the UK Certification process.
PERO is a UK manufacturer who offers 95% Certified product although it is a very limited range.
YARRAH is from the Netherlands and offers a good range of 100% Organic Tinned and Dry dog food, along with some snacks. They do split their range into different groups i.e. puppy, gluten free etc.
Smaller Specialist Companies such as Darlings Real Dog Supply and Lily's Kitchen claim to supply but I found nothing that says they are Certified, so it would be best to telephone them to check what percentage, and what ingredients, are Organic.
Telephone is better because I have found many companies (large and small) just do not respond to emails!
Certainly you would expect to see a "logo" or "hallmark" if a company meets the certification requirements.
For example the YARRAH product is EKO Certified on the packaging
My vote for the UK currently goes to YARRAH, purely because of the menu range available, which allows for plenty of variety when feeding your dog, whether you prefer wet, dry or a combination of both.
For stockists call:- England: Survival Wholefoods 0156 861 4147