Horses were common animals of the Pleistocene in Eurasia and right across Siberia into North America. At https://blogs.scientificamerican.com/tetrapod-zoology/spots-stripes-and-… … the greatest concentration of cave art is in southern France and northern Spain where horses and bison are the most frequently depicted animals. The paintings and etchings of horses reveal an unexpected amount of variation. These are the caballoids (the complex of domestic horses and their feral derivatives). Why there was an emphasis on equines is a matter of opinion. They arfe mostly stocky, tan in clour, or yellowish with a stiff dark mane – somewhat akin to Przewalski's horse of modern Mongolia, or the Selerikan horse of Pleistocene Siberia (extensively described in sources largely unknown in the western world). Pleistocene horses in North America seem to have had long flowing manes.
The Selerikan horse was first discovered in a gold mine. A tunnel happened to coincde with its burial in sediments and its hind legs protruded out of the roof. They were used to hold cables and hang lanterns. Later, the horse was removed by the Siberian Academy of Sciences (minus sits head). Several other Selerikans have been discovered in the Siberian permafrost – the carcase of a white horse was retrieved from the banks of the river Yana for example. Permafrost horse remains are also known from Alaska. Horses were able to remain sedentary on the Alaskan North Slope during the Late Pleistocene era (the so called Late Glacial Maximum), a discovery consistent with the idea that the land surface, vegetation, and pattern of wind and rainfall differed from that of the Holocene climate in the region.
Horses in Europe depicted in cave show many variations in colour, proportion, mane form, head shape etc. These features may have been exaggerated by the artists – for whatever reasons they might have had. Stripes are depicted on occasion – across the shoulders or neck. A long standing mystery is the presence in the Cave of Pech-Merle de Caberate in France of spotted horses with dark shoulders and necks. It has often been assumed the spots were an artistic licence – or have a symbolical meaning. Other animals in the same cave are spotted. However, others claim there really were spotted horses in the Palaeolithic period, similar to modern Apaloosa. There is no reason why the latter view is not true as spotted horses may have been favoured by some groups of humans. In contrast, the majority of cave art depicts horses that looked much like the wild horses that have survived on the Asian steppes (although there is an argument that spotted horses also survived in parts of greater Asia) and the Selerikan horses are direct evidence of this. See RD Guthrie, 'Frozen Fauna of the Mammoth Steppe', University of Chicago Press:1990.