How We Ranked These
Every food on this list was scored using KibbleIQ’s ingredient analysis rubric, which evaluates protein quality, filler content, preservative safety, and overall ingredient transparency on a 0–100 scale. For Shih Tzus specifically, we weighted three additional factors: small-breed-appropriate kibble size and shape (brachycephalic breeds struggle with large or spherical kibble), antioxidant-rich ingredients that support eye and skin health (beta-carotene, blueberries, vitamin E), and limited-ingredient or single-protein options for the breed’s documented allergy predisposition.
The brachycephalic mouth structure matters more than most owners realize. Banfield Pet Hospital and the American Veterinary Dental College both flag Shih Tzus as one of the most dental-disease-prone breeds, driven partly by crowded teeth in a small, compressed jaw. The mechanical act of chewing firm kibble provides modest dental benefit — but only if the dog can actually chew rather than gulping whole pieces. Small, flat, or bone-shaped kibble at 5–8mm is significantly more dog-friendly for a Shih Tzu than standard round 10–12mm kibble. That’s a real reason Royal Canin’s breed-specific kibble shape is a thoughtful feature — it’s just stacked on a formula we can’t otherwise recommend.
Our Top 5 Picks
1. Wellness CORE — A (90/100)
Wellness CORE Small Breed pairs deboned chicken, turkey, and chicken meal with salmon oil, ground flaxseed, and built-in glucosamine and chondroitin. The Small Breed kibble is sized appropriately for brachycephalic mouths (5–6mm), and the antioxidant blend includes blueberries, kale, and spinach — relevant for a breed with elevated eye-disease risk. The 34% protein at moderate fat keeps muscle maintenance solid for an 8–16 lb frame.
Best practical choice for most Shih Tzu owners: A-grade ingredients, small-breed formulation, antioxidant support for eyes, and built-in joint nutrients for the patellar luxation risk the breed carries. Read our full Wellness CORE review → · Shop on Amazon →
2. Nulo Freestyle — A (90/100)
Nulo Freestyle Small Breed delivers 30%+ protein from named animal sources (turkey, salmon, trout, lamb) at moderate fat, with BC30 probiotics for digestive stability. The Small Breed kibble is sized appropriately for brachycephalic breeds, and the low-glycemic carb base (chickpeas and lentils at moderate inclusion) is a good match for Shih Tzus that tend toward obesity — blood sugar stays stable between meals and satiety holds longer.
Particularly useful for Shih Tzus with environmental or food sensitivities — the clean, short ingredient list minimizes accidental triggers. Read our full Nulo review → · Shop on Amazon →
3. Acana Heritage — B (88/100)
Acana combines 60% animal content with regional vegetables, fruits, and legumes at controlled inclusion. The whole-food antioxidant content (blueberries, apples, kale, pumpkin) is useful for a breed with eye-disease predisposition. For allergic Shih Tzus — a common presentation — the Acana Singles line offers duck-only or mackerel-only limited-ingredient formulas in small-breed kibble sizes.
Strong mid-premium choice, especially Singles for elimination-diet trials. Read our full Acana review → · Shop on Amazon →
4. Fromm Gold — B (84/100)
Fromm Gold Small Breed combines duck, chicken meal, and menhaden fish meal with probiotics, salmon oil, and moderate grains (oatmeal, barley). The small kibble is appropriate for a Shih Tzu’s jaw, and the moderate-grain formulation adds fiber bulk that supports stool consistency — a quality-of-life issue for a long-haired breed where stool hygiene matters more than average. Clean multi-decade recall record.
Good fit for Shih Tzus that haven’t thrived on grain-free formulas or have mildly sensitive digestion. Read our full Fromm review → · Shop on Amazon →
5. Merrick Grain-Free — B (80/100)
Merrick Grain-Free Small Breed leads with deboned meats, with sweet potato and peas as the carb base, plus glucosamine and chondroitin. The small kibble size is jaw-appropriate, and the single-meat-first ingredient deck (beef, lamb, salmon, or duck depending on recipe) is useful for allergy-aware feeding. Widely available at Chewy, PetSmart, and Petco.
A solid value option — mid-premium ingredient quality at noticeably below A-tier pricing. Read our full Merrick review → · Shop on Amazon →
What to Look for in Food for Shih Tzus
Small-breed kibble sized for a brachycephalic mouth. Standard adult kibble (10–12mm round) forces a Shih Tzu to either crack pieces with compromised teeth or swallow whole (which offers no dental benefit and can trigger reflux or aspiration in a short-muzzled dog). Small Breed or Toy Breed variants at 5–8mm are sized appropriately. Flat or star-shaped kibble is generally easier than round for brachycephalic breeds. If your Shih Tzu consistently leaves kibble in the bowl while eating meat or treats eagerly, the kibble size may be the problem — not picky eating.
Named animal protein first, not corn or rice. A healthy adult Shih Tzu needs roughly 400–550 kcal/day depending on activity. Muscle maintenance requires real protein — 26–30% dry matter is a sensible range — from named meats (chicken, salmon, turkey, lamb, duck). Avoid formulas where corn, wheat, brown rice, or “meat by-products” lead the label. This is the core issue with Royal Canin Shih Tzu: the face-friendly kibble design is stacked on a brewers-rice-and-chicken-by-product base that drags the overall ingredient quality to C-tier.
Antioxidants for eye and skin health. Shih Tzus carry elevated risk for progressive retinal atrophy, dry eye (keratoconjunctivitis sicca), and corneal ulcers. Antioxidants — vitamin E, vitamin C, beta-carotene, lutein, zeaxanthin — support retinal and corneal health. Whole-food sources (carrots, blueberries, kale, pumpkin, spinach) in the ingredient deck contribute beyond just synthetic vitamin supplementation. Omega-3 fatty acids from fish sources also support tear film integrity, which matters for dry-eye-prone Shih Tzus.
Allergy-aware formulation. Shih Tzus are among the top allergy-presenting breeds at vet clinics, with skin flare-ups, paw-licking, recurrent ear infections, and anal gland issues all commonly diet-triggered. Cutting corn, wheat, soy, and artificial additives eliminates a meaningful share of typical dietary triggers. If symptoms persist after an 8–12 week clean-diet trial, a single-protein limited-ingredient diet (duck, lamb, fish, or a true novel protein) under vet supervision is the next step.
Portion control and dental hygiene. Shih Tzus tend to become overweight, which compounds respiratory distress (brachycephalic airways are already compromised), patellar luxation risk, and spinal issues. Weigh meals in grams with a kitchen scale; 10–15% of daily calories can come from training treats, never more. Pair dry kibble with daily tooth-brushing or veterinary-approved dental chews — Shih Tzus are dental-disease-prone by breed, and dry kibble alone doesn’t replace mechanical plaque removal. Many Shih Tzus need a professional dental cleaning every 12–18 months throughout adult life.
Bottom Line
The best food for a Shih Tzu is small-breed in size, clean in ingredient deck, and allergy-aware in protein selection. Wellness CORE Small Breed is our top pick for brachycephalic-friendly kibble, A-grade ingredients, and built-in antioxidant and joint support. Nulo Freestyle Small Breed offers a cleaner short-ingredient-list alternative for allergy-sensitive Shih Tzus. Acana Singles is the right pick if your Shih Tzu needs a limited-ingredient elimination trial. Skip Royal Canin Shih Tzu (C/58) — the breed-specific kibble shape is one of the thoughtful elements of Royal Canin’s line, but the underlying formula is brewers rice first and chicken by-product meal second, and you can get the size plus real ingredients from the foods above. Pair whatever you feed with daily brushing, scheduled portions, and regular vet dentals.