Writing & examples by MistyofSunrise free lineart
Since grey is one of those tricky genes (especially since your favorite equine seems to be constantly changing in appearance
) I thought I would throw together a little guide based on my own research and observation. Hopefully this will be helpful as you design and/or age your equines!
Grey is a dominant gene, so every horse that carries even one grey (G) gene WILL grey - no exception. There is no evidence to prove that there is any difference between homozygous (GG) and heterozygous (nG) in how they grey and how fast the process goes. Family line seems to have more influence - a sire/dam that greys slowly will be more likely to have offspring that also grey slowly, etc. While grey can start to show subtly from birth (babies may be born with whitish "goggles" around their eyes) or be barely visible for those first years, virtually all horses with grey w