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 ingredient transparency on a 0–100 scale. For Shih Tzus with dental disease, we weighted O’Neill 2021 (The Veterinary Journal) on canine periodontal disease prevalence, Wallis 2019 (BMC Veterinary Research) on small-breed periodontal predisposition, Niemiec 2008 on retained deciduous teeth in toy breeds, the AVDC (American Veterinary Dental College) 2019 staging guidelines, the VOHC (Veterinary Oral Health Council) Seal of Acceptance criteria, Roudebush 2005 on tooth-brushing efficacy, and the AAHA 2019 dental care guidelines.
Our ranking weights small kibble shape that brachycephalic Shih Tzus can pick up and chew without slip-and-gulp, AAFCO feeding-trial substantiation per WSAVA Pillar 4, grain-inclusive cardiac-conservative formulation per the FDA 2018–2019 advisory, and named-meat-first ingredient quality. We did not weight any maintenance kibble as “dental” without VOHC Seal of Acceptance — only Hill’s Prescription Diet t/d, Royal Canin Veterinary Dental, and Purina Pro Plan Veterinary Dental DH carry VOHC acceptance and require veterinary prescription.
Our Top 5 Picks
1. Royal Canin Shih Tzu — B (76/100)
Royal Canin Shih Tzu is our top pick because the kibble is breed-engineered — small triangular kibble shape designed for the Shih Tzu’s foreshortened brachycephalic jaw conformation, requiring deliberate pick-up and chew rather than gulp-and-swallow. Omega-3 EPA/DHA fortification supports skin and coat health (Shih Tzus have known atopy susceptibility per Picco 2008). The recipe is grain-inclusive (corn, brewers rice, wheat) and AAFCO-substantiated for adult Shih Tzu maintenance. Manufactured by Mars Petcare with on-staff veterinary nutritionists meeting all 7 WSAVA assessment pillars.
The breed-targeted kibble shape is the most directly relevant feature for Shih Tzu mealtime safety and chewing efficacy. Read our full Royal Canin Shih Tzu review → · Shop on Amazon →
2. Purina Pro Plan Small Breed — B (80/100)
Purina Pro Plan Small Breed delivers AAFCO feeding-trial substantiation (Method 1, gold standard) on a small-kibble formulation. The recipe uses chicken as the first ingredient, includes whole grain rice and oat meal as the carbohydrate base, and provides moderate calorie density appropriate for adult small-breed maintenance. Manufactured by Nestlé Purina with on-staff veterinary nutritionists meeting all 7 WSAVA Global Nutrition Committee assessment pillars.
For owners who want WSAVA-pillar-complete feeding-trial-substantiated small-breed feeding without the breed-specific premium of Royal Canin Shih Tzu. Read our full Purina Pro Plan review → · Shop on Amazon →
3. Hill’s Science Diet Small Bites — B (78/100)
Hill’s Science Diet Small Bites uses chicken meal as the primary protein, whole grain wheat and oats as the carbohydrate base, and is AAFCO feeding-trial substantiated. The kibble is sized appropriately for small-breed jaw conformation. Hill’s veterinary nutrition team is the largest in the consumer kibble space and the company manufactures the VOHC-accepted Prescription Diet t/d — the maintenance Small Bites is not VOHC-accepted but shares the same R&D infrastructure.
For owners whose veterinarian recommends Science Diet (the most-recommended consumer brand at U.S. veterinary clinics) but whose Shih Tzu does not yet warrant prescription t/d. Read our full Hill’s Science Diet review → · Shop on Amazon →
4. Wellness Complete Health Toy Breed — B (84/100)
Wellness Complete Health Toy Breed earns the highest ingredient-rubric score on this list (84/100) thanks to deboned chicken and chicken meal as the top two ingredients, whole grain barley and oatmeal as the carbohydrate base, and small kibble sized appropriately for toy-breed jaw conformation. The grain-inclusive formulation aligns with FDA-advisory cardiac-conservative feeding. Wellness uses formulation-only AAFCO substantiation rather than feeding trial.
For owners willing to pay a premium for higher-quality named meats while staying inside the FDA-advisory grain-inclusive frame, Wellness Complete Health Toy Breed is the strongest small-breed option. Read our full Wellness Complete Health review → · Shop on Amazon →
5. Iams ProActive Health Small Breed — C (70/100)
Iams ProActive Health Small Breed is the budget small-kibble option for Shih Tzu owners managing the cost of routine dental care (annual or biennial professional cleaning under anesthesia adds up). Manufactured by Mars Petcare with WSAVA-aligned veterinary nutrition support, Iams uses chicken as the first ingredient with whole grain corn meal and ground whole grain sorghum providing the grain-inclusive carbohydrate matrix. Our rubric scores it at C/70 due to corn-second-ingredient positioning, but the formulation is FDA-advisory-conservative.
For owners on a budget who would otherwise shop into a grain-free retail kibble for cost reasons, Iams Small Breed is the meaningful upgrade in DCM-conservative direction. Read our full Iams review → · Shop on Amazon →
What to Look for in Food for a Shih Tzu with Dental Disease
Daily tooth brushing is the gold standard, not food choice. Per Roudebush 2005 and the AVDC 2019 guidelines, daily tooth brushing with veterinary-formulated toothpaste is the most effective at-home dental intervention — more effective than any food alone. Two-minute brushing sessions, focused on the buccal (cheek-side) surfaces of upper premolars and molars, where calculus accumulates fastest, drive measurable plaque reduction. Most owners brush 0–3x per week; the AVDC recommends daily. Multi-day gaps reset the plaque-mineralization clock. Use poultry-flavored or peanut-butter-flavored canine toothpaste; never human toothpaste (xylitol toxicity).
Schedule professional cleaning under anesthesia annually for Shih Tzus. Per the AAHA 2019 dental care guidelines, small breeds typically need annual or biennial Comprehensive Oral Health Assessment and Treatment (COHAT) under general anesthesia — full-mouth probing, dental radiographs, supra and sub-gingival scaling, and extraction of irreparably affected teeth. Owners frequently postpone “dental cleaning” due to anesthesia concerns; per Bellows 2019, modern multimodal anesthesia protocols on healthy small-breed adults have ASA-equivalent risk profile to other elective procedures. Pre-anesthetic bloodwork and chest radiographs identify candidates for protocol adjustment.
Consider VOHC-accepted dental chews as adjunctive. Per the VOHC Seal of Acceptance criteria, products earning VOHC acceptance have demonstrated meaningful plaque or tartar reduction in clinical trials. VOHC-accepted dental chews include Greenies, Whimzees Stix, OraVet, and Tartar Shield. These are adjunctive to brushing, not substitutes. Caloric load matters — a single Greenies Teenie has approximately 25 kcal; for a 10-pound Shih Tzu on 350 kcal/day, that’s 7% of daily calories, leaving room for 1 daily Greenie within the 10% treats budget. See our dental chews guide.
Address retained deciduous teeth before age 1. Per Niemiec 2008, approximately 25% of toy and small breeds retain deciduous (baby) teeth alongside erupted permanent teeth, creating early-life crowding and food-impaction risk. Veterinary dental extraction at the time of spay/neuter (typically age 5–8 months) addresses this efficiently. Owners often miss retained deciduous teeth at the routine spay/neuter and discover crowding-driven periodontitis at age 3–4 when restoration becomes more complex. Ask the spay/neuter veterinarian to specifically check for retained deciduous teeth.
Address periodontitis-related pain that may suppress food intake. Per the AVDC 2019 guidelines, advanced periodontitis (Stage 3–4) causes meaningful pain that can suppress food intake and lead owner-perceived “picky eating” or weight loss. Soft-food trials (canned wet food, soaked kibble) may improve intake during periodontal flares pre-COHAT, but are not long-term solutions — canned food alone is associated with faster plaque accumulation than dry kibble per Harvey 1996. Post-extraction soft-food feeding for 1–2 weeks is appropriate; revert to dry kibble once oral pain resolves.
Stay grain-inclusive per the FDA advisory. Per the FDA 2018–2019 dilated cardiomyopathy advisory, grain-free formulations heavy in peas, lentils, chickpeas, and potatoes have been temporally associated with diet-associated DCM. Shih Tzus do not have notable DCM predisposition, but cardiac risk-stacking is hard to justify for a chronic feed in a breed already managing brachycephalic respiratory burden. Grain-inclusive (oats, barley, rice) is the current safer maintenance default per WSAVA and ACVIM 2020.
Bottom Line
Shih Tzus rank in the top 10 breeds for periodontal disease per O’Neill 2021 due to crowded dentition, shallow alveolar bone, retained deciduous teeth, and reduced mechanical chewing. Diet alone does not prevent or treat periodontal disease; daily tooth brushing per Roudebush 2005 and routine professional cleaning under anesthesia per the AAHA 2019 are the standard-of-care. Our top pick is Royal Canin Shih Tzu for breed-engineered small kibble. Purina Pro Plan Small Breed and Hill’s Science Diet Small Bites are WSAVA-aligned alternatives. Wellness Complete Health Toy Breed is the premium named-meats option. Iams Small Breed handles the budget tier. See also our general Shih Tzu feeding guide, general dog dental health guide, and dental chews guide. Address retained deciduous teeth at spay/neuter per Niemiec 2008, schedule annual COHAT under anesthesia per the AAHA 2019, and brush daily with poultry-flavored canine toothpaste per the AVDC.