Roan and Ticking Genetics in Dogs: What Causes the Speckled Pattern

Roan and ticking are two related coat patterns that both involve coloured hairs intermixed with white areas, but they are visually and genetically distinct. Both patterns sit on top of white spotting — a dog must first have white areas (from the S locus or other sources) before roan or ticking can modify those areas.

What Is Ticking?

Ticking is the presence of small, isolated spots of colour within otherwise white areas. It typically appears as small round specks — similar to freckles — spread across the white portions of a dog's coat. Ticking is common in Beagles, English Setters, Australian Cattle Dogs, and many hunting breeds.

Ticking is controlled by the T locus. Dogs with at least one T allele express ticking in their white areas. Dogs that are t/t (homozygous for no ticking) remain cleanly white in their white patches.

What Is Roan?

Roan is a more uniform intermixing of coloured and white hairs throughout the white areas, giving a softer, more blended look than the discrete spots of ticking. Roan ranges from lightly flecked (blue roan) to heavily pigmented, where the white areas appear nearly fully coloured.

Roan is caused by the Gr (graying/roaning) locus, separate from ticking. It is common in Cocker Spaniels (blue roan, chocolate roan), English Springer Spaniels, and German Wirehaired Pointers.

How Roan and Ticking Interact

A dog can carry both roan and ticking genes simultaneously. In breeds like the Australian Cattle Dog, this produces the distinctive speckled coat that looks ticked on a roan background. The two patterns complement each other but are genetically independent.

Breeds Where Roan and Ticking Matter

• Australian Cattle Dog: Classic blue or red speckled coat
• Cocker Spaniel: Blue roan and chocolate roan are registered colours
• Beagle: Ticking creates the classic tri-colour speckled appearance
• English Setter: Heavy ticking on a white base is the defining pattern
• Dalmatian: Spots are related to ticking, though the exact genetic mechanism is debated
• German Shorthaired Pointer: Liver roan is a standard colour

Testing

Not all DNA companies test comprehensively for roan and ticking loci, as these genes are less commercially important than merle or colour loci. Breed-specific panels from PawPrint Genetics and Embark may include T locus testing for relevant breeds. If roan is important to your breeding program, confirm which variants your testing lab covers.