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.
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.
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.
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.
Addison’s disease occurs when the adrenal glands stop secreting necessary natural steroid hormones. In the Nova Scotia Duck Tolling Retriever, a genetic form of Addison's disease can occur in puppies.
There are multiple genetic causes of cleft palate within the Nova Scotia Duck Tolling Retriever breed. The most common form has been identified as CP1.
The CLPS genetic variant causes development of cleft palate and/or cleft lip, sometimes also accompanied by syndactly (fused toes), in Nova Scotia Duck Tolling Retriever puppies.