The new year will see a crop of thoroughbred foals coming into the world. Thoroughbreds have limited coat colours, compared with some other breeds, so it’s not unusual to see gangs of bay or brown foals in the springtime nursery paddocks. Although they may look the same from a distance, every foal is different and unique; each is born with distinguishing marks that never change, enabling individual identification throughout his life.
So, what makes a given horse unlike any other? We can’t take his fingerprints, obviously, but other features are just as useful. There are five basic horse colours: black, brown, bay, grey and chestnut (note that the technically correct spelling “chesnut” is insisted upon by many breed societies, such as the Suffolk Horse Society). All other colours are mixtures or combinations of these.
Colours can be deceiving. Many greys start life as bay, chestnut or even black, changing colour as they grow up. Most greys get lighter with age and end up white, even though white is not a recognised colour. Many don’t realise that greys have black skin.Using terms such as “light bay” or “dark bay” is discouraged, because bays often become lighter in the summer. But an adult bay will always be a bay, a chestnut always a chestnut and so on.
With roan and dun, two colours are evenly mixed throughout. With skewbalds and piebalds, the two base colours occur in large patches that will never change. Even “identical” skewbald or piebald twin foals have slight but definite differences in their patch patterns.
White socks on the lower limbs are fixed from birth; they never shrink down the leg or creep up towards the knee or hock. Even the irregular border between the coloured coat and the white on the leg will always be the same.
Natural white markings on the face are also permanent and unchangeable. The shape and positioning of a forehead star, relative to the horse’s eyes, remains throughout life, as will a stripe down the nose, a blaze or a snip between the nostrils. These grow as the foal grows, but always in the same proportion to the rest of the head.
Permanent markings can also be black, such as a dorsal stripe or zebra stripes on the legs.
On your marks
Plenty of horses have no natural markings — indeed, some breed standards forbid them. So how are these horses unique and individual?
In certain places, the hair of the coat forms a whorl, where the hairs swirl around a centre point. These whorls are characteristic of an individual horse. The position of the centre point of the whorl never changes, and the combination of whorls over the whole horse can be used to identify him.
There is usually one whorl on the forehead, between the eyes, but it can be low, high, dead-centre or displaced to one side. There are almost always whorls under the mane, on either side of the crest, anywhere from just above the withers to right behind the ears. A complete absence of crest whorls is rare and in itself is an identifying feature.
There may be whorls on the chest, over the jugular vein on the neck, on the cheeks, belly, stifles and several other places. They are often not symmetrical — perhaps one on the left jugular groove but not on the right. Believe it or not, there is some credible evidence that the position and direction of hair whorls on the head may be linked to temperament.
On the insides of the forelegs, above the knees, are the chestnuts — patches of soft horn that remind us that horses once had additional digits. Some horses also have chestnuts below the hocks. The shapes of the forelimb chestnuts are unique. Whether oval, tear- or diamond-shaped, triangular or notched, they will always remain that shape.
Acquired white marks in the coat, like natural ones, are also permanent, arising when the pigment cells of the skin are damaged by pressure or injury. Many mature horses have white patches over the withers that were not there when they were young, usually from a badly fitting rug that slips back and tightens around the chest and withers.
Poorly fitting saddles can leave white patches further back, on either side of the spine, which, once present, never go. Cuts, scrapes and bruises will often leave permanent white marks, especially on the limbs.
Even muscle tissue may have a unique, distinguishing mark. Some horses have a “prophet’s thumb” mark, a large dimple or depression in the neck — a small deficit in the muscle, present from birth and unchanging through life. Very occasionally, there will be a prophet’s thumb mark on the shoulder or chest. Tradition has it that these dimples arose when the prophet Mohammed pressed his thumb into some elite mares, and that descendants with such marks will be gifted and exceptional.
The eyes have it
More subtle points can make a horse unique, such as the patterns in the iris of an eye. A “wall” eye, in which some or all of the iris is blue or pink, is obvious and will never alter. Even in brown eyes, the pattern of black and golden stripes is fixed for life.
You will never see them, but the joints in the bones of the skull are also unique. Over the top and sides of the head, the flat bone plates that make up the cranium are joined together by intricately complicated joints or “suture lines”. No two horses have the same pattern.
It is difficult to judge how a foal will turn out by looking at his conformation before weaning. Some straight-limbed foals with excellent proportions end up with weak hocks or wonky forelimbs, a ewe neck or a roach back.
Once established in an adult horse, these conformation points are there for life. Muscle conditioning and soft tissue development through proper training can improve some faults, but the basic frame will always lie underneath.
While very few horses are perfect, most are loved despite their faults and many do their jobs perfectly well. Every horse is unique — complete with markings, whorls, dimples and his own character.
In the picture
An accurate passport description is essential. All UK equines must now be microchipped, but not everyone has a microchip reader and these readers sometimes fail. A microchip may even migrate from its inserted position. A good drawing and a full written description of a horse’s colour, white marks, whorls and other identifying marks is therefore fundamental to his identification.
Vets are told that they should not use overtechnical terms when completing passports, but simple language that can be understood by any sensible horseperson. Legally, all horses must have a passport before they reach 12 months, but most breed societies insist on registration before this age, usually by the end of the year in which the foal is born. Finding whorls and marks on a fluffy young foal, however, can be tricky. Sometimes, the foal needs to grow a little for the markings to become clearer.
A passport should be updated when a colt is castrated, or if the horse acquires a permanent marking such as a significant scar, a branding mark or tattoo. Further details about colours and markings for identification purposes can be found on the Weatherbys website.
Ref Horse & Hound; 27 December 2019