Oxen are slower than horses, donkeys and camels have a worse temper, and dogs aren't as good as horses either, because you can't ride them.
Civilization might still develop, but slower.
The horse become extinct in North Africa and the Middle East around the same time that in the Americas. However, that never stopped the development of the Egyptian and Sumerian civilizations. The Egyptians were the first who domesticated the donkey and the Sumerians built chariots pulled by onagers (until this day, this is the only known epoch when these "untameable" animals were domesticated in some form). In my opinion, there is none reason to think that the donkey would be harder to breed for new races than the horses. Even the tranquil and giant draft horses of some European races are descendants of tiny, fast and also bad-tempered savage tarpans.
Obviously, the horse triumphed above the donkey in OTL. But that was only because the horse is faster than the donkey. In absense of horses, people could turn to the donkeys and create faster breeds through generations. There were some races of "running donkeys" in the 19th century that were used in hippodromes. Nothing as fast as horses, but if you think that they were only breeded with this target very lately and only for fun, you would realise that through millenia the results of such breeding would be amazing.
So there are alternatives to horses in farming, even if this would slow down things in Northern Europe, reducing the outcome because of lack of sufficient draugth animals.
There are still the oxen. In fact, the horse was a bad animal for plowing untill a Chinese invented the horse collar.
So without horses and therefore chariots, what is the likelyhood of an Indo-European migration? Would they be staying in Central Asia and Ukraine or span outward in a very limited range?
So without horses and therefore chariots, what is the likelyhood of an Indo-European migration? Would they be staying in Central Asia and Ukraine or span outward in a very limited range?
Of course they could end up importing onagers the way the dwellers of the Near East and North America did horses, ie someone else bring them in and some are captured or get lose and rounded up by natives.Even if they don't domesticate a substitute for the horse (like the Persian onager, that at that time also existed in the European part of Russia).
Lets say Persia or Babylon conquer the Sythans.So lets say horses die off in the early days of the human race before they are cultivated. How could civilizaiton progress?