Boxer vs. Bullmastiff vs. Boerboel: The Big Boxy Dogs Explained

They’re big. They’re blocky. They’ve got those distinctive square heads and that unmistakable “don’t mess with my family” vibe. But if you think Boxers, Bullmastiffs, and Boerboels are basically the same dog in different sizes — think again. These three breeds share a certain aesthetic, but their personalities, energy levels, and care needs are genuinely worlds apart.

If you’re a big-dog person in the St. Pete or Pinellas area (and let’s be honest, Florida big-dog people are a special breed of their own), here’s what you need to know before bringing one of these giants home.

Meet the Contenders

The Boxer: Big Energy, Big Heart

The Boxer is a German breed, originally developed from working mastiff-type dogs to be a versatile all-purpose dog: hunter’s assistant, cattle drover, police dog, and eventually the exuberant family companion we know today. At 60–70 lbs, the Boxer is the smallest of our three, but what it lacks in mass it more than makes up for in enthusiasm.

Boxers are famously playful — often described as “the clown of the dog world.” They’re loyal, energetic, and deeply attached to their families. They’re also brachycephalic (short-muzzled), which gives them that adorable smooshed-face look and, unfortunately, some real respiratory limitations in heat and humidity.

The Bullmastiff: The Gentle Giant Guard

The Bullmastiff was purpose-bred in 19th-century England to help gamekeepers catch and hold poachers — without mauling them. That required a dog that was powerful enough to take down a grown man, but controlled enough to hold him without serious injury. The result is a breed that is calm, deliberate, and surprisingly quiet for its size — until it isn’t.

Bullmastiffs weigh 100–130 lbs and have a lower-key energy level than Boxers. They’re affectionate with family, somewhat reserved with strangers, and capable of producing truly impressive amounts of drool. They are also brachycephalic, though less severely so than Boxers, and they’re quite heat-sensitive due to their substantial body mass.

The Boerboel: The South African Powerhouse

The Boerboel (pronounced “boo-r-bull”) is the least well-known of our three, but arguably the most impressive in raw physical terms. Developed in South Africa by Dutch settlers to protect homesteads from predators — lions, hyenas, baboons — the Boerboel is one of the largest and most powerful breeds in the world at 150–220 lbs.

Boerboels are confident, territorial, and intensely bonded to their families. They’re not brachycephalic in the same way as Boxers or Bullmastiffs, so they handle heat somewhat better — but their sheer size still makes Florida summers a management challenge. They are less common in the US but are growing in popularity among experienced large-breed owners.

How They Compare: The Key Differences

Energy Level

Energy is where these three diverge most dramatically. Boxers are high-energy dogs that need significant daily exercise — long walks, play sessions, and mental stimulation. A bored Boxer is a destructive Boxer. Bullmastiffs are more moderate — they enjoy a good walk but are equally happy lounging on a cool floor for hours. Boerboels fall somewhere in between: moderate energy, but they need enough activity to stay mentally engaged and physically healthy given their powerful build.

Trainability

Boxers are highly trainable and eager to please, though their enthusiasm can make them a bit much for first-time dog owners. Bullmastiffs are intelligent but independent — they’ll follow commands when they see the point, and they respond best to calm, consistent leadership. Boerboels are smart and capable, but their confidence and size mean they need an experienced handler from day one. All three benefit from early, positive socialization and obedience training started in puppyhood.

Guarding Instinct

All three have guard dog heritage, but it expresses differently. Boxers have a moderate protective instinct and will alert to strangers but are generally friendly. Bullmastiffs were literally bred to apprehend intruders and will take that job seriously with minimal encouragement. Boerboels are territorial and deeply protective — they’re not aggressive by nature, but they are formidable when they sense a threat. Socialization isn’t optional for any of these breeds; it’s essential.

The Florida Factor: Brachycephalic Breeds in the Heat

This is where St. Pete and Pinellas County pet owners need to pay close attention. Florida’s summer heat and humidity are genuinely dangerous for brachycephalic dogs — and Boxers and Bullmastiffs are both on that list.

Dogs cool themselves by panting. Short-muzzled breeds have narrower nostrils, longer soft palates, and smaller tracheas, which means they can’t move air as efficiently. When temperatures climb past 85°F — which in St. Pete is May through October — that cooling system becomes critically impaired.

For all three breeds, Florida owners should:

• Walk in the early morning or after sunset — never midday
• Always provide fresh, cool water and shade
• Watch for signs of heat stress: excessive panting, drooling, red gums, stumbling, or collapse
• Never leave these dogs in a car, even for a few minutes
• Consider cooling mats, elevated beds, and fans for indoor comfort
• Keep large-breed dogs like Bullmastiffs and Boerboels at a healthy weight — extra pounds make thermoregulation even harder

Boerboels, while not technically brachycephalic, still need Florida heat management given their size and muscle mass. A 200-lb dog generates a lot of heat that needs somewhere to go.

Health Considerations by Breed

Boxers are prone to heart conditions (particularly arrhythmias and dilated cardiomyopathy), certain cancers, hip dysplasia, and thyroid issues. Brachycephalic obstructive airway syndrome (BOAS) is also a concern. Regular cardiac screenings and annual wellness exams are important for Boxer owners.

Bullmastiffs face risks including hip and elbow dysplasia, bloat (GDV — a life-threatening stomach condition), lymphoma, and heart disease. Their deep chest makes bloat a real concern; feeding strategies like elevated bowls and avoiding exercise right after meals are worth discussing with your vet.

Boerboels can suffer from hip and elbow dysplasia, vaginal hyperplasia, heart disease, and juvenile epilepsy. As a relatively young breed in the US, buyers should seek reputable breeders who screen for these conditions.

Which One Is Right for You?

If you want a fun-loving, energetic companion who’s great with the kids and doesn’t mind a Florida lifestyle with appropriate heat precautions — and you have experience with dogs — the Boxer might be your match.

If you want a calm, protective presence that’s devoted to family, doesn’t demand constant activity, and doesn’t mind a Florida afternoon nap in the AC — the Bullmastiff could be a wonderful fit (bring extra towels for the drool).

If you’re an experienced large-breed owner who wants a supremely confident, powerful dog with deep loyalty and a serious protective instinct — and you have the space and commitment — the Boerboel is extraordinary. Just be prepared for people to stop and stare.

All three need experienced, committed owners, consistent training, and regular veterinary care. None of them are casual choices — but all of them are deeply rewarding ones.

Big Dogs Need Big-League Vet Care

If you share your Pinellas County home with a Boxer, Bullmastiff, Boerboel — or any large, blocky, wonderful working breed — the team at Community Animal Hospitals is here for you. We provide breed-specific wellness care, cardiac and orthopedic screenings, heat safety guidance, and everything your big dog needs to thrive in the Florida climate.

Schedule a wellness exam today and let’s keep your blocky best friend healthy, comfortable, and ready for whatever adventure (or afternoon nap) comes next.