Bullmastiff vs Old English Sheepdog

This is a genetically rooted trait in many Bullmastiffs. While they may coexist peacefully with dogs of the opposite sex, placing two males or two females together often results in severe conflict once they reach social maturity (18–24 months). This aggression is rarely "cured" through training; it is managed.

Bred to track and hold poachers silently without human direction, the Bullmastiff is an independent problem solver. They do not have the "will to please" of a Golden Retriever. If a command does not make sense to them, they will simply ignore it. This is often misinterpreted as stupidity; it is actually a refusal to perform rote tasks without high-value motivation.

While independent in thought, they are physically clingy. They will lean their 120-pound bodies against you, sit on your feet, and follow you from room to room. This constant physical presence can be overwhelming for owners who value personal space.

This is a "Velcro" breed in the truest sense. They were bred to work closely with shepherds and drovers, never straying far. In a modern home, this translates to a dog that may panic when left alone. Destructive chewing, howling, and house soiling are common symptoms of distress if isolation training is not started immediately in puppyhood.

The OES has a unique, ringing bark often described as "two pots clanging together." It is loud, deep, and can become a nuisance. They are alert watchdogs and will vocalize at delivery trucks, neighbors, and squirrels. This makes them poor candidates for apartments with noise restrictions.

As a drover's dog, the OES controls movement. In a family setting, this often manifests as nipping at the heels of running children or "body checking" people to move them. While not aggressive, this behavior can be frightening for toddlers and annoying for guests.

While generally social, some OES lines—particularly males—can develop aggression toward other dogs of the same sex around social maturity (18-24 months). This requires vigilant management in multi-dog households.