Is your dog itchy and scratchy? It could be fleas or seasonal allergies, but did you know that your dog's itchy skin could be due to food allergies? Dog food allergy is the third most common hypersensitivity skin disease after flea allergies and seasonal allergies. If you are interested to know more, take a look at Hypoallergenic Dog Food. You may not realise that your dog has a dog food allergy because adverse food reactions often mimic other itchy skin diseases.Adverse reactions to food in dogs can be split into two main categories: food allergy and food intolerance. Food allergy is an immune-based reaction to food, and can occur after prolonged exposure to one brand, form or type of food. Food intolerance is not immune-based, and can occur after a single exposure.Regardless of the actual type of adverse food reaction, the signs that you will see are generally the same. Dogs with food allergies often have non-seasonal itchiness, sometimes accompanied by gastrointestinal problems. This itchiness can vary in severity from the occasional scratch to a maddening itch that leads to self trauma and infection.The areas that are most commonly affected by dog food allergy are the feet, face, armpits, perineal region, inside the thighs, rump and ears. Interestingly, about one quarter of dogs with adverse reactions to their diet will only have problems with their ears.Every level of the gastrointestinal tract can be damaged by diet-related allergies. Gastrointestinal signs of food allergies include vomiting, diarrhoea, abdominal pain and increased bowel movements.Any of these signs in your dog could suggest a food allergy. This is especially true if you have a young dog. One third of all of these allergies occur in dogs under 1 year of age. Dogs less than 6 months of age with itchy skin problems are very likely related to their diet.If your dog has any of these signs, the first thing to do is to visit your veterinarian to get a check over. Your dog may have a flea problem or non-food related allergic skin disease. If you have ruled out other causes of these signs with your vet, then it is time to start a dietary elimination trial. This is where you feed a special food as the only food source to your dog for at least 6 weeks.The best kind of food to feed in an elimination trial is a hypoallergenic diet. These are specially designed to prevent your dog's immune system from recognising and attacking the proteins in the food. For more info, visit Hypoallergenic Dog Food.