The words Dog Breed Info with the letter D inside of a black paw print

Bull Mastweiler

Bullmastiff / Rottweiler Mixed Breed Dogs

Information and Pictures

Close Up head shot - Diesel the Bull Mastweiler

Diesel the Bull Mastweiler at 6 years old—"This is Diesel. I rescued him from a kennel and he shares his home with another rescue dog named Jake. Diesel is like a big brother to Jake and luckily they have got along from day 1. Diesel enjoys walks and playtime with Jake. I'm a fan of Cesar Millan and learnt a lot from his training."


The Bull Mastweiler is not a purebred dog. It is a cross between the Bullmastiff and the Rottweiler. The best way to determine the temperament of a mixed breed is to look up all breeds in the cross and know you can get any combination of any of the characteristics found in either breed. Not all of these designer hybrid dogs being bred are 50% purebred to 50% purebred. It is very common for breeders to breed multi-generation crosses.

  • IDCR = International Designer Canine Registry®
  • DRA = Dog Registry of America, Inc.
Front side view - A brown with black Bullmastiff/Rottweiler mix is walking down a grass. There is a soccer ball behind it.

Carla the Bullmastiff, Rottweiler mix—"We rescued Carla from a center in Wales. I saw her photo on their site and fell for her. I was so nervous in case we couldn't have her!! We traveled 200 miles to get her and it was worth every hour of it! She was 3 years old, a Bull Mastiff, Rottweiler mix and the most wonderful girl, very obedient and such a calm girl, but she would have liked a cat sandwich if she could. She would thunder past you like a horse when she ran, and boy was she strong if she wanted to be. Every day she would go in the garden and give a big deep bow then a wow in conversation with the dog across the street for 5 minutes! But sadly she suddenly took ill with a large tumor and is no longer with us."

The head of a brown with black Bullmastiff/Rottweiler mix is on a composited black layer and looking forward.

Carla the Bullmastiff / Rottweiler mix

Luna the Bull Mastweiler puppy sleeping on a couch

"Luna is a happy, confident, gung-ho puppy who has really benefitted from the advice on your website. She is my first puppy and I was getting overwhelmed by all her energy, and she was starting to show signs of stress from having to lead. Now she's right in the middle of Boot Camp, still fighting it a little but starting to relax. I think she's relieved that she doesn't have to be in charge anymore! We go for walks two to three times a day and follow your advice, she trots right along behind, head low, smiling. I didn't think I would be able to read her mind and catch her before/during a distraction but it's surprisingly easy!"

Ghana the brown Bull Mastweiler sitting on a carpet next to a couch

"This is our dog Ghana, shown here at 13 months old, 42 inches tall and 75 pounds. She is a Rottweiler and Bullmastiff mix (Bull Mastweiler). Ghana is a very sweet dog. She is very hyper when you first come home and when you give her loving, she calms down in about 10 minutes. She likes a lot of attention. She enjoys playing with other dogs including her half-brother, a full-blooded Bullmastiff. Although she is a house dog, she enjoys the outdoors. She likes tug-of-war, is a very fast runner and she likes to stand on her hind legs and dance with me."

Ghana the Bull Mastweiler as a puppy standing on a blacktop with a child about to kiss his head

Ghana as a puppy at 2 months old at the flea market saying "hi" to a little girl

Close Up - Mick the black with white Mastweiler laying on a carpet

"Look at our find! This 11-week-old male Bullmastiff / Rottweiler mix named Mick is the latest, greatest addition to our family! He's playful, energetic, loves attention, is smart, and likes to chew on everything with his extremely sharp baby teeth...even us! He's very affectionate and always excited to see us, even if we've just been away for 5 minutes. His favorite play toys are our cats. He's very devoted to our family."

Mick the Mastweiler sitting on a carpet

Mick the black with white Bullmastiff / Rottweiler mix breed puppy at 11 weeks old

Close Up - Mick the Mastweiler sitting on carpet in front of a bed

Mick the Bullmastiff / Rottweiler hybrid puppy at 11 weeks old

Close Up - Deizel the Mastweiler sitting in grass

Deizel the Bullmastiff / Rottweiler at 1 and a half years old, weighing 136 lbs

Close Up - Deizel the Mastweiler sitting in a garage

Deizel the Bullmastiff / Rottweiler full grown at 4 years old, weighing 185 lbs

See more examples of the Bullboxer Staff