Spanish Mastiff

Calm and gentle at home, independent, aloof with strangers.
A Spanish Mastiff
Photo: Bg.dog
Adult weight
64–91 kg
140–200 lb
Lifespan
10–12 yrs
Class · Watchdog
also Working

What it's like

In character it is calm, gentle with its own household and aloof with strangers. It was bred to guard the flock with little direction, so it is independent. Its deep bark can be heard a long way off.

Day to day
Activity
Happy with modest walks
Intelligence
Easy-going, simple routines
Handler demand
Needs an experienced owner
With people
Affection
Affectionate on its own terms
Loyalty
Sticks close to its people
Independence
Decides for itself
Around the home
Sensitivity
Hardy, takes a busy home in its stride
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.
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Living with one

It has a coat of medium length. It sheds through the year rather than in big seasonal moults. Plan on brushing a few times a week. It needs a moderate amount of exercise compared with other breeds.

Size and growth

A Spanish Mastiff is a giant dog, heavier even than a Great Dane. It is one of the heaviest giant breeds.

It is a massive, heavy-boned dog. Its body is longer than it is tall, its head is large and broad, and loose skin hangs in a double dewlap at the throat. The ears are medium-sized and triangular and hang flat against the cheeks. The tail is thick and carried low at rest. The coat is dense, smooth and of medium length, and comes in fawn, red, black, wolf-grey or brindle, sometimes with white markings.

Puppy growth

Reference curve · community data appears as owners log
By about 5 months, a male Spanish Mastiff puppy is already as heavy as a grown German Shepherd. They grow fastest between 4 and 5 months old. They keep growing past their first birthday, longer than a Beagle does. Most males grow into the size large-breed puppy foods are made for.
Fully grown
13 mo
Both sexes, at 99% of adult weight6
Male
Female
Shaded: expected range
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Age
Male
Female
2 months
11.1–15.8 kg 24.5–34.8 lb
11.1–15.8 kg 24.5–34.8 lb
3 months
17.8–25.4 kg 39.2–56.0 lb
17.8–25.4 kg 39.2–56.0 lb
4 months
26.4–37.6 kg 58.2–82.9 lb
26.4–37.6 kg 58.2–82.9 lb
5 months
35.8–51.1 kg 78.9–112.7 lb
35.8–51.1 kg 78.9–112.7 lb
6 months
44.3–63.3 kg 97.7–139.6 lb
44.3–63.3 kg 97.7–139.6 lb
7 months
51.1–72.9 kg 112.7–160.7 lb
51.1–72.9 kg 112.7–160.7 lb
8 months
55.8–79.6 kg 123.0–175.5 lb
55.8–79.6 kg 123.0–175.5 lb
9 months
58.8–84.0 kg 129.6–185.2 lb
58.8–84.0 kg 129.6–185.2 lb
10 months
60.7–86.7 kg 133.8–191.1 lb
60.7–86.7 kg 133.8–191.1 lb
11 months
61.8–88.3 kg 136.2–194.7 lb
61.8–88.3 kg 136.2–194.7 lb
12 months
62.5–89.3 kg 137.8–196.9 lb
62.5–89.3 kg 137.8–196.9 lb
15 months
63.3–90.4 kg 139.6–199.3 lb
63.3–90.4 kg 139.6–199.3 lb
18 months
63.4–90.6 kg 139.8–199.7 lb
63.4–90.6 kg 139.8–199.7 lb

Lifespan

No vet study has measured how long Spanish Mastiffs live yet. The 10–12 years shown is a general figure without a published source.

Where it comes from

The Spanish Mastiff guarded the merino flocks that wintered in southern Spain and moved to the northern mountains each summer, defending them against wolves since the days of the medieval Mesta. When wolves grew scarce and droving shrank to sheep sent by train, the big droving type nearly died out; a 1981 standard set out to recover it. Its breed club counts the dog in Velázquez's Las Meninas as one4,8.

The Spanish Mastiff, the mastín español, is a livestock guardian rather than a herder. Its job was to live among the flock and protect it, not to move it. Shepherds kept it with the sheep on the drove roads and in the summer pastures, and many of the dogs wore a spiked iron collar, the carlanca, to protect the throat in a fight with wolves. It also guarded farms and country estates. Since the breed was revived, it has again been used with livestock in areas where wolves remain.

Breed standard

The Spanish Mastiff is judged against standard no. 91, in group 2, Pinscher and Schnauzer, Molossoid and Swiss Mountain Dogs4.

Questions people ask

General guidance for dogs rather than a measured Spanish Mastiff 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 giant breed is most likely at the late end.

Compare with related

Mastiff
Pinschers & molossoids · Giant
Boerboel
Working · Giant
Saint Bernard
Pinschers & molossoids · Giant
Great Pyrenees
Pinschers & molossoids · Giant
Or compare the Spanish Mastiff with any breed you choose
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Sources

Uncited on this page: Lifespan — no reviewed source yet, so it is a general reference figure rather than a published one.
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Parts of this page were written by AI ·