Answer:
All foods contain purines as part of their nucleic acid content. Organs are higher in purines than muscle meats, however, please keep in mind that chicken giblets contain a large portion of gizzard, a muscle. Also, organs are not the only ingredient or even the first ingredient in Geriatrx. Remember that the dosage makes the poison. When feeding a variety of foods, specific amounts of food componenets is inconsequential.

The Optimal Health Program will explain this more fully (http://www.wysong.net/wohp/).

Also obtain a copy of Dr. Wysong's book, The Truth About Pet Foods, and the brochure, How to Apologize to Your Pet (http://www.wysong.net/products/documents/monographs/legacy/apology_pamphlet.pdf).

Please also see:

The 100% Complete Pet Food Myth: http://www.wysong.net/pet-health-and-nutrition/the-100-percent-complete-pet-food-myth.php

Does Your Pet Need A Percent of Something?: http://www.wysong.net/pet-health-and-nutrition/does-your-pet-need-a-percent-of-something.php

100 Pet Health Truths: http://www.wysongpethealth.net/