Horses were important in the lives of our ancestors both for transport and leisure pursuits. They were, of course, particularly fundamental to life in the Army – not only in the Cavalry but also in other regiments where they could be used for activities such as moving ammunition or stores, carrying despatches etc etc.
Farriers were originally a type of “horse doctor” but their role changed in the early nineteenth century after the training of veterinary surgeons commenced. The qualified veterinary surgeons were then attached to the various regiments. Consequently, by the late nineteenth century the role of the farrier was reduced and often referred to as “shoeing smith”. However, the farrier did more than simply reshoe the horses – a vital job in itself. “Every morning the farriers would walk through the lines, if on campaign, or through the stables, if at the home base, checking the horses’ hooves but also their general well being. Often it was the farrier who made the decision to put down an injured or stricken horse” 
By 1795 persons not descended from European parents on both sides were disqualified from serving in both British and East India Company armies. However they could still hold some non-combatant roles. “The only positions open to them were as assistant apothecaries, bandsmen and farriers”  These restrictions remained in place until lifted in 1833 on renewal of the East India Company Charter .
Members of the British Army can wear their badges of trade. " There is the horse shoe of the farrier which was worn on his headdress in the 18th century but much later as an arm badge. As a trade badge the farrier-sergeant wore the shoe over his three chevrons". 
- Denis Judd, author and historian. (Q&A section -"BBC Who Do You Think You Are Magazine” August 2009.)
- Fibis fact File no 1 “Researching Anglo-Indian Ancestry” by Geraldine Charles
- Digger History
A short history of the term “Farrier” website of the Farrier & Hoofcare Resource Centre