Jack Russell Terrier

Merle

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

Dominant Black (K Locus)

The Dominant Black gene (K Locus) affects pigment switching between eumelanin (black) and phaeomelanin (red or yellow) by interacting with the Agouti and MC1R genes.

Dilute (D Locus/Blue)

Several gene variants are known to produce dilute coloration in dogs. Colors are lightened (diluted) to paler shades as a result of the variants' effects on pigmentation.

MC1R including Mask, Grizzle, and Red/Cream (E Locus)

The melanocortin 1 receptor (MC1R) gene controls production of the pigments eumelanin (black) and phaeomelanin (red/yellow). Six known variants of this gene are responsible for producing markings and coat colors including melanistic mask, grizzle/domino, black, and shades of red/yellow.

Chondrodystrophy (CDDY and IVDD) and Chondrodysplasia (CDPA)

Chondrodysplasia is a short-legged phenotype characteristic of many dog breeds. Chondrodystrophy, a separate mutation, also includes a short-legged phenotype as well as premature disc degeneration and increased susceptibility to disc herniation.

Hyperuricosuria (HUU)

Hyperuricosuria is an inherited disorder characterized by elevated levels of uric acid in the urine that can lead to the formation of bladder/kidney stones.

Primary Lens Luxation (PLL)

Primary lens luxation is a painful inherited eye disorder where the lens of the eye moves from its normal position, causing inflammation and glaucoma. If untreated, the condition can rapidly lead to blindness.

Degenerative Myelopathy (DM)

Degenerative myelopathy (DM) is an inherited neurologic disorder of dogs characterized by gradual muscle wasting and loss of coordination typically beginning in the hind limbs. Testing is most appropriate for those breeds in which the clinical disease has been associated with the SOD1 allele.