The horse was well known by the Proto-Indo-Europeans, as best proven by several poetic formulas mentioning the 'swift horse', the 'horses of the sun', and using the adjectives 'characterized by good horses' and "having horses which are cared for". The formulas tell us nothing specific about the use of horses, but archaeology and history supply the necessary information.

The Proto-Indo-European term for 'horse' shows only that horses were known (nobody doubts this); it does not mean that horses were already domesticated.

Burrow (1972) notes the existence of a word for the horse which is found only in Tamil and Brahui (DED 500: Tamil ivuli, Brahui (h)ullī, and which therefore must have existed in the earliest Dravidian [...] McAlpin suggests that this early Dravidian word probably referred to the Asian wild ass, Equus Hemionus, which is native to South Asia, rather than to the domesticated horse, Equus Caballus.

As Renfrew put it in his archly-titled review of Mallory’s book – ‘They ride horses, don’t they?’ – the horse has assumed “an almost mythical significance in traditional Indo-European studies” (1989: 845).

Which components of the reconstructed Indo-European proto-culture can be used as evidence of a steppic location?... two arguments are generally singled out by the proponents of the steppic theory: the case of the horse and that of the chariot. The domesticated horse, on the one hand, and the chariot on the other, are supposedly well-attested in the shared vocabulary and are particularly valorized in the earliest Indo-European mythologies, where the sacrifice of a horse is the ultimate royal sacrifice... The most common root for the horse is certainly found in a significant number of Indo-European languages... Its absence in Slavic is all the more surprising since the historical “cradle” of the Slavs is often said to be located in the North Pontic Steppes, or close by, precisely where the earliest domestication of the horse is reputed to have occurred.

IE linguistics can agree on the reconstructed Proto-Indo-European etyma "ekwos 'horse'. . . . But let us note [that] the animal terms tell us, in and of themselves, nothing about the cultural uses of those animals or even whether they were domesticated; but only that Proto- Indo-European speakers knew of some kind of horse . . . although not which equid. . . . The fact that the equid *ekwos was the domesticated Equus cabailus spp. Linnaeus . . . come[s] not from etymology but rather from archaeology and paleontology. The most we can do with these prehistoric etyma and their reconstructed proto-meanings, without archaeological and paleontological evidence (which does indeed implicate domestication), is to aver a Proto-Indo-European familiarity with these beasts.

The significance attached to the fact that the Indogermans were acquainted with the horse . . . may have been exaggerated. We do not know the precise meaning of the Indogermanic words in question; we do not know whether they mean the domesticated or the wild animals." ... "it is difficult to see how these names can be safely used for determining the original home of the Indogermans".

Indeed Ivanov (1999), who has undertaken by far the most comprehensive study of the cognate terms for horse in Indo-European as well as the adjacent languages of Northern Caucasian and Hurrian, points out that "the Indo-European homeland need not be identical to the area of horse domestication, but should be connected to it. The ways in which names and technical knowledge . . . spread should be explored".

The significance of the horse for the understanding of the distribution of early Indo-European has been much exaggerated.

The evidence concerning horses remains nonetheless the weakest point in the case for an Indian Urheimat. While the evidence is arguably not such that it proves the Harappan culture’s unfamiliarity with horses, it cannot be claimed to prove the identity of Vedic and Harappan culture either, the way the abundance of horse remains in Ukraine is used to prove the IE character of the settlements there. At this point, the centre-piece of the anti-AIT plea is an explainable paucity of the evidence material, so that everything remains possible.... The non-invasionists should recognize the merits in the invasionist skepticism of the horse evidence found in the Harappan cities. It is one thing for Prof. B.B. Lal (one of those healthy doubters who only came to dismiss the “myth of the Aryan invasion” gradually) to cite recent finds of horse bones as proving that “the horse was duly known to the Harappans” and to quote archaeozoologist Prof. Sandor Bokonyi as confirming that the horses found in Surkotada were indeed horses (which some had refused to believe due to their AIT bias), and that “the domestic nature of the Surkotada horses is undoubtful”. It is another to deduce that the horse was simply part of Harappan life rather than an exotic curiosity; AIT defenders have a point when they maintain that the horse was not part of the Harappan lifestyle the way it was in the Kurgan culture. More work is to be done, both in digging and incorrectly interpreting the data.

We cannot hope to recapture today the terror that the mounted horse struck into the Middle East and Eastern Europe when it first appeared. That is because there is a difference of scale which I can only compare with the arrival of tanks in Poland in 1939, sweeping all before them. I believe that the importance of the horse in European history has always been underrated. In a sense, warfare was created by the horse, as a nomad activity. That is what the Huns brought, that is what the Phrygians brought, that is what finally the Mongols brought, and brought to a climax under Genghis Khan much later. In particular, the mobile hordes transformed the organisation of battle. They conceived a different strategy of war – a strategy that is like a war game; how, warmakers love to play games!

Hehn argued that, it was risky, in the attempts to reconstruct a Proto-Indo-European culture, to depend too much on linguistic paleontology, whose methodological accuracy he doubted. How can we be sure, for example, that the Proto-Indo-Europeans owned tame horses simply because we can reconstruct the word for horse (*h1ekuos)? Did they perhaps only know about the animal, without having domesticated it? Or how do we know that *h3evis denoted "goat" and not some other similar animal, and that it has not acquired the meaning "goat" later? (Arvidsson 2006, p. 255).

All the same,” I said, “when you read the prints in the snow and the evidence of the branches, you did not yet know Brunellus. In a certain sense those prints spoke of all horses, or at least all horses of that breed. Mustn’t we say, then, that the book of nature speaks to us only of essences, as many distinguished theologians teach?”
“Not entirely, dear Adso,” my master replied. “True, that kind of print expressed to me, if you like, the idea of ‘horse,’ the verbum mentis, and would have expressed the same to me wherever I might have found it. But the print in that place and at that hour of the day told me that at least one of all possible horses had passed that way. So I found myself halfway between the perception of the concept ‘horse’ and the knowledge of an individu?al horse. And in any case, what I knew of the universal horse had been given me by those traces, which were singular. I could say I was caught at that moment between the singularity of the traces and my ignorance, which assumed the quite diaphanous form of a univer?sal idea. If you see something from a distance, and you do not understand what it is, you will be content with defining it as a body of some dimension. When you come closer, you will then define it as an animal, even if you do not yet know whether it is a horse or an ass. And finally, when it is still closer, you will be able to say it is a horse even if you do not yet know whether it is Brunellus or Niger. And only when you are at the proper distance will you see that it is Brunellus (or, rather, that horse and not another, however you decide to call it). And that will be full knowledge, the learning of the singular. So an hour ago I could expect all horses, but not because of the vastness of my intellect, but because of the paucity of my deduction. And my intellect’s hunger was sated only when I saw the single horse that the monks were leading by the halter. Only then did I truly know that my previous reasoning, had brought me close to

Sanskrit has many words for the horse: aśva, arvant or arvvā, haya, vājin, sapti, turanga, kilvī, pracelaka and gho ṭ aka, to name the most prominent among them. And yet, the Dravidian languages show no trace of having borrowed any of these words; they have their own words kudirai, parī and mā [...] The Santali and Mundari languages, however, have preserved the original Kol- Munda word sādom. Not only has no linguist ever claimed that the Dravidian and Kol-Munda words for ̳horse‘ are borrowed from 'Aryan‘ words, but in fact some linguists have even sought to establish that Sanskrit gho ṭ aka, from which all modern Indo-Aryan words are derived, is borrowed from the Kol-Munda languages.