Pinto Patterns

The Pinto Patterns

The problem with identifying pinto patterns is that it's more complicated than just overo and tobiano. There are actually four patterns; overo (also called "frame" overo), tobiano, splash white (also called "splash" overo) and sabino. To further complicate things, horses can inherit more than one pattern. And to make things even MORE difficult, few people can properly identify patterns, so there is just TONS of misinformation out there, in both the real horse world and in the model world. (Just last week I read a post on one of the AOL horse boards, and a girl was vehemently explaining that sabino was an APPALOOSA pattern, and that Paint registries would not register sabino horses because they were really appaloosas - EEEK!)

Anyway, the best book I can recommend is the (much talked about!) Sponenberg Horse Color. It explains the four patterns, and has several pictures of each. It's a good start at getting a really basic understanding of the patterns.

The way I explain the patterns to folks in a way that I think makes sense is to look at the patterns in terms of the white that is on the horse. All pinto patterns have what I call "points of origin", which is the places on the horse where white will first start appearing in the most minimally marked individuals. On sabino horses, for example, the most minimally marked sabinos will have irregular blazes that continue on past their lower lip up under the jaw, and the hind stockings will extend up the stifle in a particular way, and sometimes there will be belly white. These for a sabino are the "points of origin".

Each pattern has various stages that it goes through as the horses show more and more white, so horses of a particular pattern will have progressively more white in fairly predictable manner. A tobiano with 50% white will look very similar to other tobianos with 50% white. I refer to this as "pattern progression". Progression refers to how the pattern goes from minimal expression to maximum amount of white (on a group of horses, of course - pinto patterns on individual horses do not change!) .

If you understand the "points of origin" and the "pattern progression", you can almost always tell which pattern (or patterns) are involved. There are also some "tell tale signs" as well, which are quirky little traits that seem to consistently show up in horses with the pattern, no matter how much white they have.

Soooooo - with this all in mind, let me try to explain each pattern. (Gosh, I hope all this makes sense!)

SABINO

Points of origin - on the face, legs (particularly the hind), belly and flanks
Pattern of progression - up the stifle and along the belly, sometimes up the stifle along the hindquarters to the croup, and up the front legs to the chest. Often the markings are blotchy or roany. In the most extreme cases, dark hairs will remain along the topline, ears and tail.
Tell tell signs - white extending under the jaw. An irregular patch of white on a knee (without any other white on that particlular leg). Eyes usually remain dark.

SPLASH OVERO

Kat Walk
Chestnut splash white Paint mare customized from the Breyer Lady Phase by Diane Capwell and owned by Polly Fields.

Points of origin - bald face and blue eyes, leg white (particularly on the front legs)
Pattern of progression - this pattern progresses very simply and predictably! It looks like you dipped the horse, feet-first, into a vat of white paint, and it spreads just like the horse was getting dipped deeper and deeper into the paint. In the most extreme individuals, the ears and topline will remain dark. The edge of the markings is crisp like a tobiano.
Tell tale signs- Blue eyes. Horses that consistently pass on blue eyes almost always carry this gene, and splash overos always have two blue eyes. LOTS of face white - even in minimally marked horses the entire head is often white.

FRAME OVERO

Electric Lace
Apricot dun overo Paint stallion, Rio Rondo QH#1 custom-painted by sculpting artist Carol Williams and owned by Lisa Sents.

Points of origin - along the side of the neck and along the flank. To a lesser extent on the face.
Pattern of progression - the white on the neck and flank will grow to fill the side of the horse, so that when viewed from the side the horse looks dark around the edges and white in the center (hence the term "frame"). Only in extreme cases will the white begin to extend down to the legs. The markings tend to be ragged or sometimes lacey, but not roany.
Tell Tale Signs - dark legs. Frame overos have legs marked much like oridinary horses - a small sock or two, or no markings at all. The mane and tail also tend to remain dark. Overos occasionally have blue eyes.

TOBIANOS

Points of origin - legs, along the withers, back and base of the tail.
Pattern progression - the white spreads down from the topline and up from the legs, forming the dark parts into large, roundish areas. The head and chest usually remain dark and the flanks will have one or more roundish spots. The edge of the markings is usually crisp.
Tell Tale Signs - The face is usually marked like an ordinary (unspotted) horse. All four legs and often the tail are usually white.

It's hard to explain all this over the net, where I cannot use drawings, but hopefully this will help! :-)

BTW, *all* pinto patterns are dominant, for those interested in pedigree assignment.

Lesli Kathman

lesli@vnet.net