Is ZIWI Peak or Sundays better for dogs?

Effectively tied at A/90 vs A/90 on the v15 rubric. Both are A-tier air-dried whole-prey-model recipes — the two flagship US-distributed air-dried brands. ZIWI Peak leads with novel-protein venison, 96% animal content, New Zealand green-lipped mussel, and large-breed-puppy AAFCO substantiation. Sundays leads with USDA-inspected beef, quinoa inclusion, and DTC subscription convenience. Pick ZIWI for novel-protein elimination diets and giant-breed puppies. Pick Sundays for USDA sourcing standard and quinoa-included grain inclusion.

What is the difference between air-drying and freeze-drying?

Air-drying uses warm air circulation (75-95°F over 24-48 hours) to gently dehydrate raw ingredients while preserving more nutritional structure than kibble extrusion. Freeze-drying uses sublimation drying under vacuum at -40°F to remove moisture without heat exposure, preserving the most nutritional intactness of any commercial format short of frozen raw. Both are shelf-stable. The trade-offs: freeze-dried foods need rehydration with water before serving (1-2 minutes); air-dried foods can be fed as-is straight from the bag (kibble-replacement convenience). Air-dried foods are typically denser and chewier; freeze-dried foods are lighter and more porous. For maximum nutritional preservation: freeze-dried. For maximum convenience: air-dried.

ZIWI Peak vs Sundays: Which Is Better for Your Dog?

Q: Why do air-dried recipes include green-lipped mussel?

New Zealand green-lipped mussel (Perna canaliculus, native to New Zealand coastal waters) is one of the most nutritionally dense natural sources of glucosamine, chondroitin, omega-3 EPA + DHA, and a unique anti-inflammatory fatty acid called ETA (eicosatetraenoic acid) that’s not present in fish oil. Clinical research supports green-lipped mussel for canine osteoarthritis joint-support. ZIWI Peak includes it as a structural ingredient at primary position; Sundays doesn’t include green-lipped mussel. For dogs with joint sensitivity, breed-disposition orthopedic concerns (Labradors, Goldens, German Shepherds), or sport-dog joint maintenance needs, the green-lipped mussel inclusion is structurally meaningful.

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The short answer: Effectively tied at A/90 vs A/90 on the v15 rubric. Both are A-tier air-dried whole-prey-model recipes — the two flagship US-distributed air-dried brands. ZIWI Peak leads with New Zealand free-range venison (novel protein), 96% animal-derived content (one of the highest ratios in commercial dog food), New Zealand green-lipped mussel for natural glucosamine and ETA omega-3, and AAFCO substantiation for all life stages including large-breed-puppy growth. Sundays leads with USDA-inspected beef + organ meats + quinoa (the only grain in the recipe) and US small-batch production. Pick on protein (novel venison vs USDA beef), grain tolerance (grain-free vs quinoa-included), and country-of-origin preference (NZ vs US).

The scores

ZIWI Peak Venison Air-Dried Recipe: A (90/100) — Venison, Venison Tripe, Venison Heart, Venison Lung, Venison Liver.

Sundays Air-Dried Beef Recipe for Dogs: A (90/100) — USDA Beef, USDA Beef Heart, USDA Beef Liver, USDA Beef Bone, Quinoa.

How the ingredients compare

The top-five ingredients reveal the formulation split between these two products:

ZIWI Peak: Venison, Venison Tripe, Venison Heart, Venison Lung, Venison Liver

Sundays: USDA Beef, USDA Beef Heart, USDA Beef Liver, USDA Beef Bone, Quinoa

Both products earn effectively the same v15 score, but the ingredient lineups tell different stories about how they got there — that is where the actual pick decision lives.

Where ZIWI Peak pulls ahead

Novel-protein venison for elimination-diet utility: ZIWI Peak leads with venison — a novel protein for most US dogs with no prior immunologic exposure. Sundays leads with USDA beef — common in the food-allergy trigger top six. For dogs with suspected beef sensitivities or owners running elimination-diet protocols, ZIWI’s venison is structurally aligned. ZIWI also offers Beef, Lamb, Chicken, Mackerel + Lamb, and Tripe + Lamb variants for protein-rotation diets. Shop on Amazon →

96% animal-derived content + green-lipped mussel for natural glucosamine: ZIWI Peak runs 96% animal ingredients — among the highest ratios in commercial dog food. New Zealand green-lipped mussel at #7 supplies natural glucosamine, chondroitin, omega-3 EPA + DHA, and the unique anti-inflammatory ETA fatty acid (not present in fish oil). Clinical research supports green-lipped mussel for canine osteoarthritis joint-support. Sundays’ recipe runs slightly lower animal-percentage (quinoa contributes a meaningful plant fraction) and doesn’t include green-lipped mussel.

AAFCO all life stages including large-breed-puppy growth (higher AAFCO bar): ZIWI Peak Venison is AAFCO-substantiated for growth of large-size dogs (70+ lb adult weight) — the higher AAFCO bar requiring controlled calcium percentages (1.0-1.8% on dry-matter) to prevent skeletal-development complications in giant-breed puppies. Many premium recipes meet the standard adult AAFCO bar but not the large-breed-puppy bar. Sundays is AAFCO-substantiated for all life stages but check the specific calcium percentage for large-breed-puppy growth.

Where Sundays holds its own

USDA-inspected beef + US small-batch production: Sundays explicitly uses USDA-inspected beef and organ meats as a sourcing standard. The USDA inspection mark on raw-meat input is a verification step that the source slaughter facility met federal hygiene and safety standards at slaughter and primary processing. For owners specifically prioritizing US-sourced ingredients and USDA-inspected meat sourcing, Sundays is the structurally aligned pick. ZIWI Peak is New Zealand-sourced — outstanding quality from New Zealand’s small-population free-range farming, but not USDA-inspected. Shop on Amazon →

Quinoa as a complete-protein grain inclusion: Sundays includes quinoa as the only grain in the recipe — a complete-protein pseudocereal (quinoa contains all nine essential amino acids, unusual for plant proteins), gluten-free, with low glycemic index. For owners who are uncomfortable with fully grain-free formulations (DCM-concern related, per FDA’s ongoing investigation of grain-free DCM risk) but want a single high-quality grain inclusion, Sundays’ quinoa choice is structurally aligned. ZIWI Peak is fully grain-free.

Established US DTC brand with broad subscription convenience: Sundays is a US DTC-first air-dried brand with subscription customization based on dog weight, life stage, and feeding pattern. ZIWI Peak is widely distributed in independent pet retailers, PetSmart, Petco, Chewy.com, and Amazon, but the subscription convenience is less integrated than Sundays’ DTC model. For owners wanting integrated subscription convenience with air-dried format, Sundays is the structural pick.

The bottom line

Effectively tied at A/90 vs A/90 — the pick comes down to protein, grain tolerance, and country-of-origin priority. Pick ZIWI Peak for novel-protein venison (elimination-diet utility), 96% animal-derived content, New Zealand green-lipped mussel for natural glucosamine + ETA omega-3, AAFCO substantiation for large-breed-puppy growth, and New Zealand free-range sourcing. Pick Sundays for USDA-inspected beef (US sourcing standard), quinoa inclusion (single high-quality grain for owners avoiding fully grain-free), and DTC subscription convenience with US small-batch production.