How long does a Sealyham Terrier live?

The listed lifespan for a Sealyham Terrier is 12–14 years.

How tall is a Sealyham Terrier?

The listed height for a Sealyham Terrier is 10.5 in.

Is a Sealyham Terrier good with children?

The AKC good-with-children score for a Sealyham Terrier is 3 out of 5.

When is a Sealyham Terrier full grown?

The growth size band for a Sealyham Terrier is 8–12 months.

Terrier Group

Sealyham Terrier

Sealyham Terrier is a small dog in the Terrier Group. Adult weight is 19.8 lb (male), 17.6 lb (female), height is 10.5 in, and the listed lifespan is 12–14 years. AKC describes the temperament as Alert, Outgoing, Sense of humor.

Last reviewed November 1, 2026.

Sealyham Terrier dog — Photo: Pleple2000 · CC BY-SA 3.0 · Wikimedia Commons

Lifespan12–14 years

Weight19.8 lb (male), 17.6 lb (female)

SizeSmall GroupTerrier Group

Height

10.5 in

Energy

3 / 5

Shedding

3 / 5

Grooming

3 / 5

Trainability

4 / 5

Good with kids

3 / 5

The breed record

Across 45 single-size small breeds, a lifespan midpoint of 13 years is about 0.6 years shorter than the 13.6-year average. A midpoint adult weight of 18.7 lb is about 2.7 lb heavier than the 16 lb average for those small breeds.

The listed origin is Wales. The coat is described as double, wiry, medium. The AKC energy score is 3 out of 5, 0.6 points below the group average of 3.6 for the Terrier Group. Shedding scores 3 out of 5. Grooming scores 3 out of 5. Trainability scores 4 out of 5, which is a biddable score. Good with children scores 3 out of 5. Good with other dogs scores 3 out of 5. AKC ranked this breed number 163 in 2025.

Adult size is usually reached in 8–12 months (size-band statement (Salt et al. 2017): very small dogs reach maturity at 8-12 months). AKC parent-club recommended health screenings: Ophthalmologist Evaluation and Primary Lens Luxation (PLL) - DNA Test. These are screening tests, not a list of diseases the breed is guaranteed to develop.

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