A food allergy occurs when your immune system responds defensively to a specific food protein that, in reality, is not harmful to the body. There are eight foods that cause over 90 of food
Dietary changes can cause problems especially if a dog has an allergy to an ingredient in the new food, I would move back to the old food for a while to see if the symptoms decrease in severity. The rectal itching may also be caused by parasites, anal gland issues or other irritation; but most likely the change of food is the culprit.
Most common food allergies in dogs By Juliana WeissRoessler While it has become common to watch out for the signs of lifethreatening food allergies in young children, it still comes as a surprise to some dog parents that their fourlegged companions can also suffer from food allergies.
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