When does a Shih Tzu have its first heat?

Shih Tzu

Sociable and playful, but independent, not eager to please.

Photo: Mostafameraji

Adult weight

4.5–8 kg

9.9–18 lb

Lifespan

12.8 yrs

Handler demand

Suits a first-time owner

Class · Lap dog

also Companion, Family

What it's like

In temperament the breed is lively, alert and friendly, with a proud, slightly haughty bearing. It is sociable with people and playful at home, but tends to be independent rather than eager to please.

Summary

Detail

Owners who rated their dogs' everyday behaviour found Shih Tzus calmer and more independent-minded than most, and less often among the friendliest with other dogs. With people, they were about average. Breed is only a small part of any one dog's personality, so meet the dog before you decide.

Owners in the Darwin's Ark survey1 rated their dogs on everyday behaviour, and Shih Tzu dogs were 2.1 times as likely to land in the most independent quarter (95% CI 1.76–2.54; 106 dogs), 1.6 times as likely to land in the calmest quarter (95% CI 1.25–2.1; 84 dogs) and only 0.49 times as likely to land in the most dog-friendly quarter (95% CI 0.29–0.82; 106 dogs), compared with all the dogs surveyed. On sociability with people, they looked like dogs in general1. Breed explained only about 9% of the differences in behaviour between individual dogs in that study1, so these are tendencies, not a forecast for one dog.

Day to day

Activity

Happy with modest walks

Intelligence

Easy-going, simple routines

Handler demand

Suits a first-time owner

With people

Affection

A lap or leaning dog

Loyalty

Friendly with everyone

Independence

Cooperative, with its own ideas

Around the home

Sensitivity

Average

Voice

Barks to alert, then settles

Prey drive

Usually fine with small pets

Breed explains only about 9% of how individual dogs differ in behaviour1. Meet the dog. A good breeder breeds for temperament as well as health, and matches each puppy's personality to the right home2,3.

Is a Shih Tzu right for you?

Take the breed matcher

Living with one

Summary

Detail

Kept long, a Shih Tzu's coat needs brushing through to the skin every day, with the hair on top of the head trimmed or tied up out of the eyes. A groomer's short puppy trim is the low-maintenance alternative. It needs a modest amount of exercise compared with other breeds.

Kept long, a Shih Tzu's coat needs brushing through to the skin every day, and the hair on top of the head is trimmed short or tied up to keep it out of the eyes. A groomer's short "puppy trim" is the low-maintenance alternative4.

The FCI standard describes a long coat ("outer coat long, dense, not curly")5. By its coat type, the undercoat moults, most heavily as the seasons change. As a rule of thumb for this coat: daily brushing. Plan for a modest amount of exercise compared with other breeds, judged from its FCI group: companion and toy dogs, bred for company. Owners in the Darwin's Ark survey said their Shih Tzu seeks constant activity less often than owners of other dogs did1, which bears that out. In a VetCompass study of heat-related illness across 905,543 UK dogs, the Shih Tzu's odds were not measurably different from the Labrador's (odds ratio 0.47, 95% CI 0.18–1.24)6.

Size and growth

Summary

Detail

A Shih Tzu is a small dog, about the weight of a grown Cavalier King Charles Spaniel.

A long, dense double coat falls straight or slightly wavy, often to the ground, and the hair on the muzzle grows upward, giving the face what is often called a chrysanthemum look. The head is broad and round, the muzzle short and square, the eyes large and dark, and the plumed tail curls over the back. Any colour is allowed, though in parti-colours a white blaze on the forehead and a white tail tip are prized in Britain.

Two types

The growth curve, the weight table and the size class on this page use the UK / FCI type's weights.

UK / FCI type

FCI 208

Adult weight

Males

4.5–8 kg

Females

4.5–8 kg5

Its weights are the ones used on this page.

American type

AKC standard

Adult weight

Males

4.1–7.3 kg

Females

4.1–7.3 kg7

Its weights are not the ones this page uses.

Puppy growth

Reference curve · community data appears as owners log

Summary

Detail

By about 3 months, a male Shih Tzu puppy is already as heavy as a grown Chihuahua. They grow fastest between 3 and 4 months old.

By 3 months a male Shih Tzu puppy already weighs as much as a grown Chihuahua8. It grows fastest between 3 and 4 months, when a male puts on about 0.2 kg (0.4 lb) a week. The chart keeps rising after a dog is fully grown, because many dogs keep putting on some weight into their second year8.

Expected range in kilograms: the breed's own adult weight, grown along the under 6.5 kg band of a WALTHAM growth standard8.

Fully grown

10 mo

Both sexes, at 99% of adult weight9

Male

Female

Shaded: expected range

Chart

Table

Age

Male

Female

2 months

1.5–2.6 kg 3.3–5.7 lb

1.6–2.8 kg 3.5–6.2 lb

3 months

1.8–3.3 kg 4.0–7.3 lb

1.9–3.5 kg 4.2–7.7 lb

4 months

2.4–4.2 kg 5.3–9.3 lb

2.5–4.4 kg 5.5–9.7 lb

5 months

2.8–5.0 kg 6.2–11.0 lb

2.9–5.1 kg 6.4–11.2 lb

6 months

3.2–5.7 kg 7.1–12.6 lb

3.2–5.6 kg 7.1–12.3 lb

7 months

3.5–6.1 kg 7.7–13.4 lb

3.4–6.0 kg 7.5–13.2 lb

8 months

3.7–6.5 kg 8.2–14.3 lb

3.6–6.3 kg 7.9–13.9 lb

9 months

3.8–6.8 kg 8.4–15.0 lb

3.7–6.6 kg 8.2–14.6 lb

10 months

3.9–7.0 kg 8.6–15.4 lb

3.8–6.8 kg 8.4–15.0 lb

11 months

4.0–7.1 kg 8.8–15.7 lb

3.9–7.0 kg 8.6–15.4 lb

12 months

4.1–7.3 kg 9.0–16.1 lb

4.0–7.1 kg 8.8–15.7 lb

15 months

4.3–7.6 kg 9.5–16.8 lb

4.2–7.5 kg 9.3–16.5 lb

18 months

4.4–7.9 kg 9.7–17.4 lb

4.4–7.8 kg 9.7–17.2 lb

Health and lifespan

Summary

Detail

Vets record these more often in Shih Tzus than in crossbreeds. Corneal ulcers and dry eye stand out as far more likely, and an inward-rolling eyelid is slightly more likely; all three are rated moderate. These are figures for the breed as a whole, not a prediction for your dog.

The list and these lines follow one order, the same on every breed: likelihood level (the four steps of its meter, not the exact odds), highest first; then impact, most serious first; then name, A to Z.

Conditions vets recorded more often in this breed than in crossbreeds10,11,12. Each has two ratings, on scales used for every breed: how much more likely the breed is to get it, and how serious it is for a dog that does.

•
Corneal ulcers: 10× the odds of crossbreeds, in vet records in England (VetCompass, 2017) (95% CI 7.3–14; 2,031 Shih Tzu records)10.
•
Dry eye (keratoconjunctivitis sicca): 13× the odds of crossbreeds, in UK vet records (VetCompass, 2021) (95% CI 10–18; 13,310 Shih Tzu records)11.
•
Inward-rolling eyelid (entropion): 1.57× the odds of crossbreeds, in UK vet records (VetCompass, 2025) (95% CI 1.2–2.05; 67,368 Shih Tzu records)12.

These are population figures from the studies cited, not a prediction for any one dog.

Listed by likelihood level, highest first, then by how serious it is, then by name.

Corneal ulcers
Far more likely
Impact: moderate
Dry eye
Far more likely
Impact: moderate
Inward-rolling eyelid
Slightly more likely
Impact: moderate

Flat face and breathing

Summary

Detail

The Shih Tzu is one of the flat-faced breeds. In UK vet records, flat-faced dogs were more likely to have breathing and airway problems than dogs with a medium-length muzzle, and lived shorter lives on average. Noisy breathing at rest is worth raising with a vet.

Lifespan

Summary

Detail

In UK vet records, the typical Shih Tzu lived to about 13 years, shorter than the typical small breed.

Where it comes from

The Shih Tzu, whose Mandarin name means roughly 'little lion', has Tibetan roots but was developed in China. Lion dogs sent from Tibet as tribute were prized at the Manchu court and probably crossed with the Pekingese, though the UK breed club concedes much of this is hearsay. At the imperial palace, the Dowager Empress Tzu Hsi oversaw their breeding, watching family lines and colour5,16.

The Shih Tzu's place in China faded with the end of the imperial court, and its survival came to depend on dogs taken abroad. In the nineteen-thirties Lady Brownrigg brought a small group from Peking to England, helping to found the breed in Britain. These dogs were at first shown alongside the Lhasa Apso, until the two were recognised as separate breeds. Kept chiefly as a palace companion rather than for work, the Shih Tzu is a small, sturdy dog, slightly longer than it is tall, carried with its head held high.

Breed standard

Summary

Detail

The American standard asks for a lighter dog than the UK and international ones.

The Shih Tzu is judged against standard no. 208, in group 9, Companion and Toy Dogs5. The American standard asks for a lighter dog than the UK and FCI one; both types are set out under Two types.

FCI 208: 4.5-8 kg (ideal 4.5-7.5), one range for both sexes. FCI 208's height is a one-sided maximum, so only the weight is carried.

AKC breed standard: ideally 9-16 lb for mature dogs, one range for both sexes. Its height is an ideal with outer limits rather than a type range, so only the weight is carried.

Questions people ask

General guidance for dogs rather than a measured Shih Tzu figure: most females have a first season somewhere between six and fifteen months, and cycles then settle to roughly every 180 days. Smaller breeds tend to start earlier and larger ones later, so a small breed is most likely at the early end.

Compare with related

Lhasa Apso

Companion & toy · Small

Maltese

Companion & toy · Toy

Pekingese

Companion & toy · Toy

Bichon Frise

Companion & toy · Small

Or compare the Shih Tzu with any breed you choose

Track your own Shih Tzu

Log a minute a day and watch them sit on these curves. Free.

Sources

1
Morrill et al., 2022. Ancestry-inclusive dog genomics challenges popular breed stereotypes. Science 376: eabk0639 (Darwin's Ark). ↑
doi.org/10.1126/science.abk0639
2
Dogs Trust. Finding a good, responsible breeder. ↑
www.dogstrust.org.uk/dog-advice/getting-dog/choosing-dog/finding-a-breeder
3
American Kennel Club. Screening puppy buyers: how top breeders find the best homes. ↑
www.akc.org/expert-advice/dog-breeding/screening-puppy-buyers-how-top-breeders-find-the-best-homes/
4
American Kennel Club. Shih Tzu: Dog Breed Information (Grooming / Exercise / Training). ↑
www.akc.org/dog-breeds/shih-tzu/
5
FCI. Breed standard no. 208. Fédération Cynologique Internationale. © FCI. ↑
www.fci.be/Nomenclature/Standards/208g09-en.pdf
6
Hall, Carter & O'Neill, 2020. Incidence and risk factors for heat-related illness (heatstroke) in UK dogs under primary veterinary care in 2016. Scientific Reports 10: 9128 (VetCompass). CC BY 4.0. ↑
doi.org/10.1038/s41598-020-66015-8
7
American Kennel Club. Shih Tzu breed standard. ↑
images.akc.org/pdf/breeds/standards/ShihTzu.pdf
8
Salt et al., 2017. Growth standard charts for monitoring bodyweight in dogs of different sizes. PLoS ONE 12(9): e0182064 (WALTHAM). CC BY 4.0. ↑
doi.org/10.1371/journal.pone.0182064
9
Hawthorne et al., 2004. Body-weight changes during growth in puppies of different breeds. Journal of Nutrition 134(8 Suppl): 2027S–2030S (WALTHAM). ↑
doi.org/10.1093/jn/134.8.2027S
10
O'Neill et al., 2017. Corneal ulcerative disease in dogs under primary veterinary care in England: epidemiology and clinical management. CC BY 4.0. ↑
doi.org/10.1186/s40575-017-0045-5
11
O'Neill et al., 2021. Keratoconjunctivitis sicca in dogs under primary veterinary care in the UK: an epidemiological study. CC BY 4.0. ↑
doi.org/10.1111/jsap.13382
12
O'Neill et al., 2025. Conformational eyelid disorders in dogs under primary veterinary care in the UK - Epidemiology and clinical management. CC BY 4.0. ↑
doi.org/10.1371/journal.pone.0326526
13
O'Neill et al., 2020. Unravelling the health status of brachycephalic dogs in the UK using multivariable analysis. Scientific Reports 10: 17251 (VetCompass). CC BY 4.0. ↑
doi.org/10.1038/s41598-020-73088-y
14
McMillan et al., 2024. Longevity of companion dog breeds: those at risk from early death. Scientific Reports 14, 531 (VetCompass). CC BY 4.0. ↑
doi.org/10.1038/s41598-023-50458-w
15
Dale et al., 2024. Demography, common disorders and mortality of Shih Tzu dogs under primary veterinary care in the UK. CC BY 4.0. ↑
doi.org/10.1186/s40575-023-00135-y
16
Shih Tzu Club (UK). Breed history. ↑
www.theshihtzuclub.co.uk/shih-tzu/breed-history

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