Royal Canin HP works because the “protein” in the food has been hydrolyzed — aka chemically broken down into amino acids. Amino acids are supposed to be in the blood while “protein” is not. The immune system sees undigested “protein” as a foreign invader. So a hydrolyzed protein does not cause an allergic reaction EVEN if the original protein is a problem.
The thing to watch with hydrolyzed proteins (and ESPECIALLY hydrolyzed soy protein like in Royal Canin HP) is that it is VERY high in “free” glutamic and aspartic acids (two types of amino acids). Free glutamic acid is the G in monosodium glutamate (MSG) and free aspartic acid is the ingredient in the artificial sweetener aspartame that causes MAJOR problems for a lot of people and pets. These “freed” amino acids can cause things like multiple sclerosis, dementia, brain damage, aggression, lupus and on and on.. I would cut off my right arm before I would feed any of my dogs this food long term.. Just me though.. I have MRI diagnosed brain damage suspected to be cuased by MSG and aspartame so it REALLY hits home for me…
One of the Science Diet allergy foods also has hydrolyzed protein so I would avoid it like the plague too. Short term you’re probably okay but long term this could be disasterous as these amino acids seem to accumulate and cause more problems the longer they are eaten. I used to have momentary blindness (started at age 12 years) that was caused by MSG and aspartame (and any foods with free glutamic and free aspartic acids).
These types of hydrolyzed foods will stop allergy symptoms —- but at what cost??
