Disease overview

Cone-Rod Dystrophy 2 is a type of Progressive Retinal Atrophy (PRA) that affects American Pit Bull Terriers. This is an early-onset disease that affects both rod and cones. Rod cells are responsible for vision in low light conditions and for detecting and following movement, while cone cells detect color and adjust brightness, but do not work as well in low light.

Gene name

IQCB1

Inheritance

Autosomal recessive

Signs and symptoms

Signs of change in the tapetum, which is the reflective surface of the eye, may begin as early as 1 year of age. This is followed by vision loss in dim light environments. This is a severe disease that progresses rapidly.

How is it diagnosed

Thorough examination of the eyes and clinical signs. A veterinary ophthalmologic exam can determine if there are changes in the eye that could lead to vision loss. Genetic testing assists veterinarians with diagnosis and helps breeders identify affected and carrier dogs.

Breeds at higher risk

American Pit Bull Terrier

Citations

Goldstein O, Mezey JG, Schweitzer PA, Boyko AR, Gao C, Bustamante CD, Jordan JA, Aguirre GD, Acland GM. IQCB1 and PDE6B mutations cause similar early onset retinal degenerations in two closely related terrier dog breeds. Invest Ophthalmol Vis Sci. 2013 Oct 25;54(10):7005-19. doi: 10.1167/iovs.13-12915. PMID: 24045995; PMCID: PMC3809947.

Disclaimer

Disease diagnosis and treatment should always be performed by a veterinarian. The following information is for educational purposes only.