Shih Tzu Growth Chart: What to Expect

Growth milestones from birth to 12 months

At birth, Shih Tzu puppies typically weigh 100–200 grams depending on litter size and individual genetics. By 8 weeks — the typical age for rehoming — most weigh between 0.8 and 1.5 kg. From this point, small breeds generally gain weight steadily but rapidly, often gaining 100–150 grams per week in the early weeks.

By 4 months, a typical Shih Tzu may weigh 2–4 kg, depending on its ultimate adult size. Growth begins to slow noticeably from around 5–6 months, and most individuals are close to their adult weight by 10–12 months. Some may continue filling out slightly (adding muscle and coat density) until around 12–14 months, but the major growth phase is complete by the end of the first year.

How small-breed growth differs from larger dogs

Small breeds like the Shih Tzu complete skeletal growth faster than medium or large breeds because their bones are proportionally lighter and require less time to ossify. This means that small-breed puppies reach physical maturity earlier but are also more vulnerable to growth plate injuries in the first few months of life — rough play or falls can cause real damage during this period.

Small breeds also have higher calorie needs per kilogram during puppyhood compared to large breeds, and they are more susceptible to hypoglycemia if meals are missed or spaced too far apart. Feeding a puppy-specific small-breed formula rather than a generic puppy food ensures that the nutrient and calorie density match the Shih Tzu's smaller stomach size and faster metabolism.

What healthy growth looks like — and red flags

A healthy growing Shih Tzu should gain weight steadily and consistently in the first 6 months. Week-to-week weights should generally trend upward without dramatic spikes or stalls. A puppy that loses weight across two consecutive weigh-ins, or gains no weight over two weeks, warrants a veterinary check — potential causes include intestinal parasites, infection, or inadequate caloric intake.

Visible ribcage in a growing puppy is normal — puppies at a healthy growth weight are typically leaner than healthy adults. The concern is the opposite extreme: a rapidly rounded, pot-bellied appearance in a young puppy can indicate parasites rather than healthy growth. Regular deworming and veterinary wellness checks are important throughout puppyhood.

Common misconception: many owners worry their Shih Tzu puppy is "too small" at 8–12 weeks and overfeed as a result. Puppies at the lower end of the breed range are not abnormally small — they are simply fine-boned individuals. Overfeeding a small-breed puppy accelerates growth inappropriately and can affect bone development. Let a vet assess growth trajectory rather than comparing to photos online.

Transitioning to adult food

The transition from puppy to adult food for a Shih Tzu should happen around 10–12 months of age, when most individuals have reached or are very close to their adult weight. Adult small-breed formulas have lower calorie density and adjusted calcium-to-phosphorus ratios appropriate for a dog that is no longer growing.

Transition gradually over 7–10 days by mixing increasing proportions of adult food with the puppy food to avoid digestive upset. After the full transition, recalculate daily portions based on adult weight and adjust to maintain the ideal body condition score of 4–5 on the WSAVA 9-point scale.