The most commonly mistaken horse colour among people as they assume Grey is its own colour. This is not true; a Grey horse is always a horse of another colour. Greying, or greying out, is a process where this coloured horse turns Grey over time. This is due to the hair loosing pigment. Horses that carry the Grey gene often are born a darker shade of their colour, this has lead to the saying ‘a Black horse is born Grey and a Grey horse is born Black’.

Stages of Grey

There are 5 basic stages of Grey, these are the stages a greying horse may go through. Some people clump 2 of the stages together resulting in resulting in 4 stages that people consider. Not all horses go through these stages, or go through these stages in this order. Many times the close stages will run into each other and it can be a bit hard to completely label a horse as a stage when it is really transitioning between the two stages. Horses that are bred to go through these stages quickly are seen to get more depigmentation of the skin on the face as well (seen on breeds such as the Lippizan).

First sign of greying: There is no true name for the true first stage which is when the beginnings of grey hairs start coming in. Usually they can be seen on the face first then slowly spreading across the body. A horse that gets the greying around the eyes first can be said to have goggles. Then, finally, when there is enough grey hairs present the coat starts taking on different colours which have names as follows.

Stage 1: Rose Grey and Steel Grey (or Iron Grey). Horses with red pigment will turn a pink rust colour on the coat as it first starts the greying out process, this is called Rose Grey. Horses with black pigment turn a slate blue colour on the coat which is called Steel Grey. This isn’t always true however, as some red pigmented horses will go Steel Grey and vice verse.

Stage 2: Dapple Rose Grey and Dapple Steel Grey. Some people simply refer to any shade of grey with dapples as Dapple Grey where as others prefer to specify the shade of Grey with the Dapples. As with shades, it can be confusing due to the shades running together. Due to this, I prefer to consider all Grey horses as Dapple Grey instead of basing the name off of the shade of the horse. Here the horses have started to transition into the Dapple Grey stage, however, their tinged colour (most noticeable with Rose Greys) is still present on their coats.

Stage 3: Dapple Grey. The horse is now completely a shade of grey and it is no longer possible to tell what the base colour would have been. The horse is covered in dapples and the mane and tail should be a darker grey or even light grey.

Stage 4: Light Grey, or White Grey. The horse keeps getting lighter and lighter and the dapples fade away leaving a solid light (sometimes white) Grey behind over the entire coat and mane and tail. These horses are often mistakenly referred to as being White however they are truly Grey. It is said by some that it is the homozygous grey horses are the ones that go Light Grey.

Stage 5: Flea Bitten Grey. Some horses produce pigmented ticks of hairs over the entire body. These horses can transition from Dapple Grey to Flea Bitten or they can transition from Light Grey to Flea Bitten Grey depending on the individual. The ticks, or Flea Bites, can be a black based colour or a red based colour. Some claim that the colour of the Flea Bites reflect the base colour of the horse where others say this isn’t true. Others also say that it is the heterozgous Grey horses that end at Flea Bitten Grey.

Grey Genetics

There is one Grey gene which is dominant. You could consider the Grey gene the most dominant gene of all as no matter what colour the horse is, if there is a Grey gene it will turn Grey. It is said that heterozygous Grey horses are the horses that will end up Flea Bitten and that Homozygous horses will end up Light Grey, although this seems true to a small collection of grey horses, I would like to see a study on a large scale to prove this correct before stating without a doubt that it is. Genetic testing is available for the Grey gene.