They have small litters and irregular heat cycles which may be a challenge if breeding is the plan. But for the benefit of the dog, there are health concerns: they do not have “typical” hearts and need an echocardiogram at least once a year. PLL or Primary Lens Luxation will need surgery to save their sight. Laryngeal Paralysis can cause them to suffocate and is difficult to diagnose and detect. Deafness is also something common that can affect this breed.  These concerns must be seriously thought through before committing to getting a Miniature Bull Terrier.