Back to top


Bullmastiff Dog Breed

Aliases: Bullmastiff, Bull Mastiff

Life Span: 8 to 10 years, though some have lived up to 14 years
Litter Size: 4 - 13 puppies with the average little size being 8.
Group: AKC Working, Utility, Guardian Dogs
Color: Fawn or Brindle or Red, each with Black markings on the head.
Hair Length: Short
Size: Extra Large
Shedding: Moderate Shed
Male Height: 25-27 inches (63-69 cm.)
Male Weight: 110-133 pounds (50-60 kg.)
Female Height: 24-26 inches (61-66 cm.)
Female Weight: 100-120 pounds (45-54 kg.)
 General info courtesy of Additional information about this breed can be found on their website.

Thyroid Disease - Medium Risk

The Bullmastiff ranks #70 among all breeds for autoimmune thyroiditis prevalence. While this is not a high risk breed, there is still a good chance of disease transmission through breeding. Therefore, all dogs intended for breeding should be tested first. 

 Rank Among Breeds  Number of Dogs Tested  Percent of Dogs With Disease
 #70  1,169  5.8%

You can download the full report (on all breeds) by the Michigan State University Diagnostic Center for Population and Animal Health. Here

Other Health Problems

Though the Bullmastiff is a healthy and athletic dog, it is prone to several health problems:

  • Hip dysplasia - A common occurrence in dogs. This is a condition in which the hip joint wears down, causing pain and problems with mobility. Owners can choose to treat with pain medications, activity, and sometimes surgery in severe cases. Occurs over time.
  • Elbow dysplasia - The same situation as hip dysplasia, but in the elbow area. Often caused by the larger bond structure of this particular breed.
  • PRA ( Progressive Retinal Atrophy ) - The retina begins to deteriorate, causing troubles with sight in the dog.
  • Hypothyroidism - A slowed thyroid condition that can cause the body to not function properly. Treatment can include thyroid replacement supplements and monitoring of thyroid levels.
  • Entropion - The inward rolling of the eyelid.
  • Lymphoma cancer - Quite common in this breed and can progress rapidly, beginning with fatigue and lethargy, then pain and problems with basic activities and functions. Often results in the need for chemotherapy or other cancer therapies, but many times require euthanasia.