The best way to compare canned and dry foods is to convert these to a dry matter basis (DMB). To do this, first subtract the percentage of moisture given on the label from 100%.
For example, a food that's 75% moisture would have a DMB of 100%-75% or 25%. A food that's only 10% moisture would have a DMB of 100%-10% or 90%.
Second, divide the nutriet by the DMB. So if the food has a DMB if 25% and 10% protein as fed, then the percentage of protein would be 10% divided by 25% or 40% protein. In the second example where the DMB is 90%, if that food has 18% protein as fed, the amount of protein based on dry matter would be 18%/90% or 20%
Keep in mind is that percentages of various nutrients says nothing about the quality or digestibility of those nutrients. Fortunately there are several sites that provide good information about what pet food labels say and don't say. A search for "how to read pet food labels" should turn up multiple hits. Information from veterinary nutritionists may be less biased than that of pet food companies, although some of the latter (such as Hill's) offer some good pointers.
NOTICE: The information provided on this site is not a substitute for professional medical advice,
diagnosis, or treatment. Never delay or disregard seeking professional medical advice from your
physician or other qualified health provider because of something you have read on Wellsphere.
If you have a medical emergency, call your doctor or 911 immediately.