How To Detect Gluten Allergy Best Way To Detect Gluten Intolerance In Dog?

Best way to detect gluten intolerance in dog? - how to detect gluten allergy

Hello, I suspect that my dog may have an intolerance to gluten?
I am in the United Kingdom, how can confirm or deny my suspicion?
Are there home kits available?
Are blood tests accurate?
Thank you.