Old English Sheepdog

Multidrug Sensitivity is caused by a deletion in the ABCB1 gene, also known as the multidrug resistance 1 (MDR1) gene, and is characterized by neurotoxicity following the use of certain common drugs. Dogs with two copies of MDR1 will exhibit multidrug sensitivity. Some dogs with 1 copy of MDR1 may also exhibit multidrug sensitivity.

The intensity coat color gene variant causes an extreme dilution of phaeomelanin (red or yellow pigment), resulting in a cream to white coat in dogs.

This DNA-based parentage test uses microsatellite marker analysis to compare the DNA profile of an offspring to the profiles of possible parents.

Progressive rod-cone degeneration (PRCD) is an inherited form of late-onset progressive retinal atrophy (PRA) that has been identified in many dog breeds.

A dominant variant of the R-spondin-2 gene produces the longer mustache and eyebrows seen in wire-haired dogs and other breeds.

Two variants in the Keratin-71 gene are associated with curly hair in dogs. Dogs with these curl variants have curly coats or wavy coats depending on how many copies of the allele they possess.

Five recessive variants in the fibroblast growth factor-5 (FGF5) gene are associated with long hair phenotypes in dogs.

White spotting patterns that occur in many dog breeds do not have a uniform genetic basis, and the genetics are complex. In piebald/parti/random white spotting, the extent of white pattern expression varies, and markings are often asymmetrical.

Merle is an incompletely dominant coat color pattern characterized by irregularly shaped patches of diluted pigment and solid color.