The following observations were made during a general study of Greek horsemanship, but, being somewhat controversial and turning upon points of textual criticism and the interpretation of technical terms, they may perhaps be of interest to scholars rather than to the public.
(1) iv 2. 

‘It is not only to save the corn from being stolen that a safe stall is good, but because it becomes obvious whenever the horse is [not] carrying out his corn.’
This sentence evidently describes some clear symptom of disease, for Xenophon continues: ‘Should you observe this happening, you may know that the body, being overcharged with blood, requires attention, or is overtired and needs rest, or that barley-sickness (κριθίασις) or some other sickness is making its onset. Just as with men, so with horses, all diseases are easier to cure at the onset than when they have established themselves and been treated mistakenly.’
The nature of ‘barley-sickness’ (colic) is excellently explained in Delebecque's commentary, but that of the warning symptom is doubtful, and depends on the precise meaning to be given to ἐκκομίζῃ. The manuscripts insert a negative particle before it; this is deleted by modern editors on the evidence of Pollux i 209: 

‘There is a disease of horses, barley-sickness and congestion of the blood through surfeit. And when they “carry out” their corn, then one must remove it and feed grass only, or some other light diet.’