Health issues: The Bullmastiff dog breed is quite likely to hip dysplasia, cancer, tumours, eyelid problems, PRA and boils at the lip and bloat which will need meals in small portions throughout time. Effectively good apartment dogs and good watchdogs. The Bull Mastiffs dog's height is 25 to 27 inches with the bitches measuring 24 to 26 inches. Well-known was developed as a ratter so a watchdog.