There are significant differences between these 2 choices. If you can't decide between them, you could always use both in a rotation.
I've never used k9Natural, but it appears to be a raw frozen diet, not an air dried diet. So it has to be kept frozen or refrigerated, where ZP does not. ZP has vitamins/minerals added to it while k9naturals does not.
k9natural contains fruits and vegetables. They have also chosen to add in blood to their formulas. Here's the ingredients on their lamb formula:
Ingredients / Composition:
Lamb meat, lamb bone, lamb blood, lamb green tripe, lamb liver, broccoli, cauliflower, carrot, spinach (chard), cabbage, apple, pear, lamb hearts, lamb kidneys, eggs, green lipped mussel and garlic.
Guaranteed Analysis (Frozen values):
Minimum Crude Protein 11.3% Minimum Crude Fat 21% Maximum Crude Fiber 0.7% Maximum Moisture 61%
Here's the lamb formula ingredients on ZiwiPeak -
Lamb - Meat 57%
Lamb - Liver, Lung, Tripe, Heart and Kidney 34%
Green-lipped Mussel 3%
Lecithin, Chicory Inulin, Kelp, Parsley, naturally preserved with mixed tocopherols.
Vitamins: Vitamin D3 Supplement, Vitamin E Supplement, Thiamine Mononitrate, Riboflavin, d-Calcium Pantothenate, Folic Acid, Vitamin B12 Supplement, Thiamine Hydrochloride
Minerals: Iron amino acid complex, Copper amino acid complex, Manganese amino acid complex, Zinc amino acid complex, Selenium Yeast, Potassium Bicarbonate, Calcium Carbonate