Disease overview

Cone-Rod Dystrophy is a type of Progressive Retinal Atrophy (PRA) that causes retinal degeneration. 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

NPHP4

Inheritance

Autosomal recessive

Signs and symptoms

Signs of change in the tapetum, the reflective surface of the eye, may begin in dogs as early as 5 weeks old. Subsequent symptoms include vision loss in dim light environments and progressive visual deficits.

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 have or will lead to vision loss. Genetic testing assists veterinarians with diagnosis and helps breeders identify affected and carrier dogs.

Breeds at higher risk

Standard wire-haired Dachshund

Citations

Wiik AC, Wade C, Biagi T, Ropstad EO, Bjerkås E, Lindblad-Toh K, Lingaas F. A deletion in nephronophthisis 4 (NPHP4) is associated with recessive cone-rod dystrophy in standard wire-haired dachshund. Genome Res. 2008 Sep;18(9):1415-21. doi: 10.1101/gr.074302.107. Epub 2008 Aug 7. PMID: 18687878; PMCID: PMC2527698.

Ropstad EO, Narfström K, Lingaas F, Wiik C, Bruun A, Bjerkås E. Functional and structural changes in the retina of wire-haired dachshunds with early-onset cone-rod dystrophy. Invest Ophthalmol Vis Sci. 2008 Mar;49(3):1106-15. doi: 10.1167/iovs.07-0848. PMID: 18326738.

Palánová A, Schröffelová D, Přibáňová M, Dvořáková V, Stratil A. Analysis of a deletion in the nephronophthisis 4 gene in different dog breeds. Vet Ophthalmol. 2014 Jan;17(1):76-8. doi: 10.1111/vop.12092. Epub 2013 Sep 3. PMID: 23998563.

Disclaimer

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