AGE.
The question, “at what age can an entire animal be altered?” admits of a simple answer, to wit, “as soon as the testicles can be easily reached—as soon as they appear outside of the abdominal cavity, and are found in the inguinal canal.” But although it can be performed at that epoch, or deferred to any period of after life, it must be remembered that it is easier and less dangerous in young than in older animals, and that with the former it is a simple operation, producing, ordinarily, no noticeable alteration in the other functions, and but rarely followed by accidents.
A period between eighteen months and two years is generally preferred for horses, though, according to some authors, even a much earlier date may be chosen, some English veterinarians being accustomed to operate at as early a date as ten days from birth. It is immaterial, however, at what precise time the operation may be performed, since it is a conceded point that the earlier it is done the better.