Laryngeal paralysis (LP) is a genetic disorder that results in breathing difficulties which can be made worse by physical activity and may lead to suffocation in severe cases. The condition may require surgery to alleviate breathing difficulties. Symptoms of the disease can include a respiratory murmur, wheezing, reduced tolerance for exercise, voice impairment, difficulty breathing and collapsing events in severe cases. In some cases, the respiratory difficulties can be fatal. A mutation has been identified in the Bull Terrier and Miniature Bull Terrier breeds that constitutes a major risk factor and can be used to diagnosis an early onset form of laryngeal paralysis in these breeds. Dogs carrying two copies of the mutation are considered to be at an increased risk of developing the disease.

• Bull Terrier
• Miniature Bull Terrier

A (CLEAR/NORMAL): These dogs have two copies of the normal gene and will neither develop laryngeal paralysis nor pass this mutation to their offspring.

B (CARRIER/NOT AFFECTED): These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop laryngeal paralysis but will, if bred, pass the mutation to 50% of its offspring, on average.

C (AT RISK/AFFECTED): These dogs have two copies of the mutation associated with this disease and are susceptible to developing laryngeal paralysis.