Bull Mastiff

Basic Information


livestock dog, mastiff (bulldog)

Area of Origin:


Original Function:

estate guardian

Today's Function:


Avg Size of male:

Height: 25-27 Weight: 110-130

Avg Size of Female:

Height: 24-26 Weight: 100-120

Other Name:


Pic 1



Although the mastiff is one of Britain's oldest breeds, its immediate descendant, the bullmastiff, is probably a fairly recent development. It is true that occasional references to the bullmastiff, or crosses of the mastiff and bulldog, can be found as early as 1791; however, no evidence exists that these strains were bred on. The documented history of the bullmastiff begins near the end of the 19th century, when poaching game from the large estates had become such a problem that the gamekeepers' lives were endangered. They needed a tough courageous dog that could wait silently as a poacher approached, attack on command and subdue but not maul the poacher. The mastiff was not fast enough, and the bulldog was not large enough, so they crossed the breeds in an attempt to create their perfect dog; the aptly named "gamekeeper's night dog." The preferred color was dark brindle, as it faded into the night. As the breed's reputation grew, however, many estate owners chose the dogs as estate sentries and preferred the lighter fawns, especially those with black masks, a coloration reminiscent of their mastiff ancestry. Breeders began to aim for a pure-breeding strain rather than relying upon repeating crosses between the mastiff and bulldog. They worked for an ideal animal that appeared to be 60 percent mastiff and 40 percent bulldog. By 1924, the breed was deemed to be pure and was recognized by the English Kennel Club. AKC recognition followed in 1933.


The bullmastiff is gentle and quiet, a devoted companion and guardian. It is not easily roused, but once threatened it is fearless. It is stubborn and cannot easily be goaded into action against its will. Some can be aggressive toward strange dogs, but it is generally good with other household dogs and pets. It is good with children, but it may not be playful enough to satisfy some children. The bullmastiff needs a firm but loving home. It is not for fragile or timid owners.


1. Major concerns:gastric torsion, CHD, elbow dysplasia

2. Minor concerns:entropion

3. Occasionally seen: PRA

4. Suggested tests:hip, elbow, (eye)

5. Life span: 8 to 10 years

Form and Function

This nearly square breed should be powerful and active ? a combination of strength, endurance and alertness. It should appear to be 60 percent mastiff and 40 percent bulldog. Its gait is smooth and powerful, but its angulation is moderate. Its coat is short and dense, and its expression keen and alert. These attributes allowed the bullmastiff to both overtake and over-power intruders.