Dry eye (much more likely); Blood blister in the ear flap (more likely)8,9
No sourced figure
Class
Watchdog
Companion
Which suits you
Size
The American Bulldog is larger on average: about 36 kg (79 lb) as an adult, against 25 kg (55 lb) for the American Staffordshire Terrier.
Temperament
They differ most on loyalty (American Bulldog: sticks close to its people; American Staffordshire Terrier: bonded to its family) and on sensitivity (American Bulldog: hardy, takes a busy home in its stride; American Staffordshire Terrier: average).
Alike
Both are rated the same on affection: a lap or leaning dog.
Neither is the better dog in general. Which suits you depends on your home, your days and the care you can give.
Breed explains only about 9% of how individual dogs differ in behaviour10. Meet the dog. A good breeder breeds for temperament as well as health, and matches each puppy's personality to the right home11,12.
Puppy growth
Reference curves · both sexes
Summary
Detail
The American Bulldog grows to the heavier adult, about 36 kg against the American Staffordshire Terrier's 25 kg.
Expected weight in kilograms, both sexes: each breed's adult weight grown along the 30–40 kg band of a WALTHAM growth standard13 and the 15–30 kg band of a WALTHAM growth standard13.