No definite rules can be laid down for the amount of work horses should be called upon to perform, so much will depend upon the character of the work, their age, quality, condition, season, the nature of the country, food, and general management. Nothing requires more careful watching. If unaccustomed to the work, or not in condition, then the horses should be gradually inured to it, to prevent injurious fatigue or breaking down. Work is sometimes estimated by the number of hours employed, by the distance travelled, by the weight carried or drawn, and by the resistance overcome; but the circumstances which lead to variations in the results of horse labour are so numerous that it is impossible to deal with them separately, and they must be met by the experience of the owner as they arise. The old aphorism, that "it's the pace that kills," is applicable to the hunter and racehorse as well as to the draught horse; and it must be remembered that in proportion as the pace is increased, so must the duration of labour, as well as the weight to be moved, be diminished.
Horse-power is most advantageously employed when the pace is slow, and the hours of labour prolonged in proportion. It has been remarked that draught horses can work long hours, and draw very heavy loads, if they are not over-paced; but to demand from them quick movement, in order that a day's work may be completed at an early hour, will, if continued from day to day, materially shorten their periods of useful existence. In illustration of this, the following examples are given. It is required, as the daily work of two pairs of horses, equal in every particular, to transport twenty-four tons of merchandise a distance of two miles from a given place; one pair is occupied only six hours in drawing three four-ton loads, and returning with the empty dray; the other pair, similarly loaded, is two or three hours longer doing the same distance. The effect of the two arrangements will become perceptible in a few months; for although the first pair will rest in the stable at least two hours of the twenty-four more than the second pair, the latter will exhibit less fatigue, maintain better condition, and wear the longest. If the natural pace of a draught horse is three miles an hour, he may, if not overloaded, travel fourteen or sixteen miles in five to six hours; but to compel a horse whose natural pace is only two, or two and a half miles an hour, to accomplish that distance in the same time, will certainly injure him; while if the same horse work for ten hours on the same distance he will probably last as long as, if not longer than, the faster-paced horse, and probably keep in as good condition, even on a smaller allowance of food. When two horses work together, the pace of the slowest should be taken as the standard of speed; though it is always better to have them as closely matched in this respect as possible. It is the same when a large number of horses are travelling together; the rate of travel should be governed by the pace of the slowest horses. Overwork is, like underfeeding, false economy, and, if continued, shortens the horse's useful life; and it must be remembered that more injury can be inflicted by a few days', or, indeed, for that matter, a few hours', overwork than it will take weeks, or perhaps months, to repair. If the labour is severe or long, it is well, if possible, to allow an interval of rest during its performance, if only for a short period, and, if necessary, a mouthful of food and water. For horses working slowly for several hours, a rest of twenty or thirty minutes at the end of four hours greatly benefits them, as during the interval they have time for a meal. A longer fast than four hours is also not advisable, for reasons before given.
In tramcar work, which is, on the whole, pretty heavy, a maximum of fourteen miles a day is considered a fair amount of work per horse, for seven days in the week. If a horse is severely pushed one day, he must have a corresponding amount of rest to recuperate on following days; for instance, two days' hunting in the week is estimated as sufficient for a horse in good condition, the other days being devoted to rest and exercise. Of course, in addition to the influences which we have already mentioned as operating in this matter, the manner in which the horse is made to do his work by the rider or driver counts for much: a skilful, considerate, and humane man getting much more work out of a horse, with less fatigue or injury to the animal, than one who is inexperienced, stupid, or brutal. A good horseman should know when his horse is over-exerted, or discouraged, and relieve him accordingly; and the animal's efforts should be stimulated by a kindly word, or encouraging pat, just as his fear or over-excitement ought to be allayed in the same way. The watchful eye and the sympathetic heart of the real horseman are everything to the horse.