The accepted way to compare the protein levels of dog foods is by dry weight analysis, which looks at the protein in the dry element of the food. This link explains and gives examples
https://www.dogfoodadvisor.com/choosing-dog-food/dry-matter-basis/On the face of it, wet foods (raw, and also processed cans and trays) appear to have lower levels of protein when you look at the labels. The labels also show around 70% moisture in wet foods, and around 10% moisture in kibbles. When you do a dry weight analysis the protein levels appear to change dramatically. The wet foods will have a much higher % of protein in their dry matter than kibbles.
But that doesn't take account of the amount of the food actually fed to the dog. Dogs fed kibble are typically fed less (in weight) than dogs fed a wet food. When you compare the actual weight of food you have to ignore the dry weight analysis and go back to looking at the labels. Then you often find that the difference in the actual weight of protein fed to kibble fed dogs and that fed to wet food fed dogs is minimal.
As an example:
I used to feed James Wellbeloved kibble to William. Looking at the JWB guidelines and from memory, I think he used to have 200g per day. Dry Weight analysis works out at 20% protein. The product information states as packaged it contains 22% protein. So William was eating 44g protein per day (200g x 22% = 44).
William has been raw fed for about 7 years and has 300g per day. A typical food is Natural Instinct Natural Chicken. Dry Weight Analysis works out at 42.8% protein. The product information states as packaged it contains 14.1% protein, so William is eating 42.3g protein per day (300g x 14.1% = 42.3).
It will of course vary from food to food. But just using Dry Weight Analysis to compare foods doesn't give an accurate comparison. You have to look at the weight of food actually fed.
I hope that's clearer than mud
