Hereditary Eye Disease In Bullmastiffs

This handsome fellow is Bronson, a Bullmastiff.  The breed was created by crossing mastiffs and bulldogs.  They are a solid, stocky breed with a fun personality.  Because of their size and guarding ability, it is important to socialize them at an early age.  Females weight between 100 and 120 pounds.  The males are even larger.  The ones I see often weigh about 140 pounds.  Bronson is one of the most well-behaved dogs I have ever met.  He is a great ambassador for his breed. 

Unfortunately, Bullmastiffs are susceptible to a medical problem which eventually causes blindness.  Name the disease.  There is extra credit available if you know the mode of inheritance.



Progressive retinal atrophy is a condition which causes blindness.  In dogs that suffer from the disease, the retina degenerates.  Usually night vision is lost first.  People tell me their pet seems confused in the dark or does not want to go outside at night.  As the condition progresses, all vision is lost.  Blindness may occur at any age.  Unfortunately, there is no treatment for this condition. 

In Bullmastiffs, the disease is caused by an autosomal dominant gene.  That means all individuals with this gene will eventually suffer vision problems.  A company called Optigen (Ithaca, New York) developed a test for this condition.  I recommend testing all Bullmastiffs before purchase and/or breeding.  Further information on testing is available at


Published by kristennelsondvm

Dr. Kristen Nelson grew up on a farm in Watertown, Minn., where she developed a deep love for animals of all kinds. She received a Doctor of Veterinary Medicine degree from the University of Minnesota, College of Veterinary Medicine. Kris then completed a small-animal internship at the prestigious Animal Medical Center in New York City. In addition to writing and speaking, she cares for small and exotic animals in Scottsdale, Az. Dr. Nelson is widely quoted in the media. Her credits include Ladies’ Home Journal, USA TODAY, the Los Angeles Times and numerous radio and television interviews. Dr. Nelson has written two books, Coated With Fur: A Vet’s Life and Coated With Fur: A Blind Cat’s Love. Kris and her husband Steve share their home with rescued cats, birds and a dog.

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