We don’t really know a lot about horse care, unfortunately, apparently because it just wasn’t something that chroniclers were interested in (or understood enough to write about). Horses do appear often in medieval accounts of crusades, but usually only to say that there were a lot of them, and everyone was happy, or there weren’t enough of them, and everyone was unhappy. Also, it depends on which crusade - for the First Crusade, hoof care probably wasn’t great. But for the later crusades you’re a lucky horse! The people organizing those crusades were careful to ensure that you and your hooves were well taken care of.
First Crusade
Knights on the First Crusade, probably started out with two or three horses, which meant they had to bring along a few servants to take care of them. The servants might have been armed foot soldiers who fought in battles as well, but otherwise their main function was taking care of you, their lord’s main warhorse, and any other horses and pack animals that they brought with them. John France estimates that
“In association with the knights alone a minimum of 20,000 horses would have begun the journey, and in addition there were pack and draught animals including oxen for the carts. The servants needed in order to look after these 20,000 alone would have constituted a substantial army.” (Victory in the East, pg. 126)
The crusaders walked/rode all the way to Jerusalem, and sometimes it was a rough journey. Even when they were still in Europe, the armies experienced some difficulty marching through Hungary and into the frontier with the Byzantine Empire. Once they were in Constantinople though, the crusade restocked their food and supplies, which probably means you would be groomed and fed and re-shod in Byzantine stables.
Unfortunately the journey from Constantinople to Jerusalem was much more difficult. The crusaders battled the Seljuk Turks during their journey through Anatolia, and spent a year besieging Antioch. After securing Antioch, there were even more hardships on the way south to Jerusalem. So many horses were lost in these battles that at one point, one crusader estimated that only 700 horses remained. New horses could be captured in raids against the Seljuks, but sometimes knights ended up riding ponies, donkeys, or oxen - or they had to walk, which was considered highly undignified.
The crusaders were sometimes near starvation. Your knight might be so desperate that he would cut open your skin and drink your blood. Your fellow horses that were killed in battle, or died along the way, were certainly eaten - as were mules, dogs, camels, and any other flesh that the crusaders could find and cook, including (on one occasion when they were totally desperate for food) the bodies of dead Muslim soldiers.
In 1099 the crusaders reached Jerusalem. While they were besieging the city, a fleet of ships from Genoa arrived on the coast. Some of the ships were dismantled and the supplies were used to build new siege towers. Although no one says so directly, it’s pretty likely that some of the scrap nails and metal from these ships would have been used to re-shoe you and the other horses.
In Jerusalem
The crusaders established a kingdom in Jerusalem and a few other crusader states in the east in the 12th century. We don’t have a lot of narrative evidence about the horses there either. You might have a tougher time in the crusader states if you were a horse imported from Europe. The climate was dryer and the terrain was rockier and rougher on your feet. But there were also native-bred horses and the crusaders adapted to using them as well. There were clearly a lot of blacksmiths who made weapons and armour for knights, but also items for you too:
“Most of the metalwork manufactured in the Latin East was of a utilitarian nature. Blacksmiths spent most of their time manufacturing spikes, nails, tools and other items, above all horseshoes” (Crusader Archaeology, pg. 159)
Crusader-era archaeological sites are a pretty valuable source of information about daily life in the kingdom, a picture we often don’t really get from chronicles and other literature. Horseshoes and nails often show up in the archaeological record.
The most information that we have is probably for Templar horses. The Templars constructed stables in what they called the “Temple of Solomon”, actually the al-Aqsa Mosque. They had their own blacksmiths and they were even supposed to provide free horseshoes to knights who joined the order for a limited time (i.e. they weren’t full members and weren’t expected to buy their own horseshoes). The Templars were soldiers, but at the same time they were also monks and they were expected to spend much of their day praying. But there were special provisions for blacksmiths, who did not have to go pray if they were busy shoeing horses.
Later crusades
By the Third Crusade, crusaders usually travelled to the east by sea, now that there were friendly crusader ports along the Mediterranean coast. Preparations for Richard I of England’s crusade included ships to transport horses. You needed specialized equipment to get you onto the ship and keep you there - bigger walkways, reinforced decks, and stalls and harnesses to keep you in place and, most importantly, to keep you from falling overboard. Horses also needed food and water, in addition to all the food and water supplies for soldiers.
Among the supplies Richard brought with him were “at least 60,000 horseshoes”, which cost the king £50, according to the Pipe Roll accounts from the Exchequer in 1190.
Unfortunately we don’t have the same detailed accounts for the preparation of other crusades, but Louis IX made similar preparations for the Seventh Crusade in 1248. His fleet included horse transports, and he also purchased several thousand horseshoes.
So, you’d be taken care of as well as possible under the circumstances! On the First Crusade your hooves might be in rough shape, until your shoes could be repaired somewhere along the way. But you would have seen most of your fellow horses killed, or dead of disease or starvation, and/or eaten. In the crusader states, blacksmiths were plentiful and important for you as well as your knight. On later crusades, horses were very well taken care of. Planners made sure to include special accommodations for horses as well as enormous supplies of shoes and nails.
Sources:
John France, Victory in the East: A Military History of the First Crusade (Cambridge University Press, 1994)
Adrian J. Boas, Crusader Archaeology: The Material Culture of the Latin East (Routledge, 1999)
Christopher Tyerman, England and the Crusades, 1095-1588 (University of Chicago Press, 1988)
Christopher Tyerman, How to Plan a Crusade (Penguin, 2015)
Malcolm Barber, The New Knighthood: A History of the Order of the Temple (Cambridge University Press, 1995)