Before the days of qualified vets
Animal treatment in the countryside has always been mainly the duty of the farmer. It was quite usual to find the farmer dosing his own stock. His horsemen kept recipe books for internal and external medicines that could include such things as arsenic or mercury - serious traditional poisons that people today would have difficulty obtaining, let alone using as medicine - as well as milder hedgerow herbs like wild garlic.
This habit of on-farm dosing went on even after it was common to find a vet in every large town.
1377 Michaelmas.
William de Threlkeld by Adam Crossby his attorney appeared against Robert Marshal of Kirkeby in Kendale, in a plea that when the same Robert had undertaken to cure a certain horse belonging to the said William of a certain weakness by which it was hindered in the right leg and the said Robert at Crosby Ravensworth so negligently and incautiously cut the veins and sinews that the same leg became withered, whereby William altogether lost the profit of the said horse. Defendant did not come. Case adjourned until the octave of S. Hilary. De Banco Roll, 468, m. 139. (British History)
Farrier...
Physical problems with horses' feet were referred to the farrier, who shod them according to their way of going. It was the farrier's reponsibility to keep horses on the road. If one cast a shoe out in the country, he was expected to put it right at his own cost.
<< Here's a sample of the different shoes he might produce. The foot sizes vary from farm Clydesdales to light hunters and Fell ponies.
The farrier was expected to deal with horses' teeth as well as their feet.
... and dentist
A horse's teeth grow constantly and sometimes wear into sharp edges or points which cause pain by cutting its lips and the sides of its mouth. Naturally the horse then works badly and is hard to control, not to mention that it becomes a weak, "poor doer" and loses weight because it can't chew its food properly.
This rasp was used to remove those rough edges. Horses that are kindly handled appear to go to sleep during this yearly inspection and servicing. It seems to be hypnotic for them, rather than the nerve-tingling experience humans associate with dentistry. The equine dentist usually has hold of the horse's tongue to steady its head and prevent the tongue itself being rasped. It also stops the horse closing its teeth on the instrument!
The rasp is 18" long. It has a wooden handle, rounded edges, and a rim either side of the face to stop it slipping off the row of teeth it's working on. Once the teeth are levelled off, the sound of the rasp changes and it moves freely over the teeth. It's all over for another year.
Early 20th C recipes
From "The Complete Horseman" by William Scarth Dixon, 3rd edition of 1912; to his credit, he recommends calling the veterinary surgeon at the first sign of illness. It wasn't always so with everyone, however. His vet said of another customer: "He about kills his horse and then sends for me."
Here are some of the remedies he suggests:
Indigestion
Indigestion is shown by a tight skin, rough "harsh" looking hair and lack of condition. An old powder we used to give our horses as a corrective once or twice a week was composed of Flowers of Sulphur, White Resin, Nitre, and Black Antimony in equal quantities. A tablespoon in a warm bran mash is a dose.
Colic
A remedy recommended by Capt. Hayes is a drench composed of Laudanum 2 oz, Turpentine 2oz, Linseed oil 1½ pints.
Catarrh
Powders comprised of Sulphate of Magnesia 3 oz and Powdered Nitrate of Potash 3 drs should be given three times a day in the drinking water. In very bad cases 30 drops of Belladonna may be given twice or three times a day. Fowler's Solution of Arsenic may be given for four or five days at first, then a powder consisting of Sulphate of Iron 2 drs, owdered Gentian, Powdered Camomile and Powdered Ginger 1 dr each. This powder should be given in a feed of corn once a day for ten days.