Stabled horses need plenty of clean drinking water, especially in winter months when dry rations tend to increase and access to grazing is limited or even denied altogether.
The drudgery involved with filling water buckets twice a day has understandably prompted many people to change to automatic waterers. Although used successfully by a large number of yards, various issues can arise when these “drinkers” are installed in place of buckets and horses are expected to help themselves.
The most common criticism of automatic waterers is that it is not possible to monitor how much a horse is drinking, although curiously this issue is never raised when horses are out at grass with a self-filling trough.
While excessive drinking is often mentioned as a sign of the hormonal condition PPID (pituitary pars intermedia dysfunction, commonly known as Cushing’s disease), this is actually seen quite infrequently.
Conversely, the possibility that a horse has Cushing’s can never be excluded if he is drinking normally.
Where the condition does occur, excess water intake can in some cases be very high — as much as three to five buckets overnight. This is invariably accompanied by excessive urination and very wet bedding. It is unlikely that a reasonably vigilant owner would fail to spot both of these signs, although this is not always the case.
If in any doubt, the drinker should be turned off or blocked, and the true intake measured with buckets. On average, a stabled horse will drink one or two buckets (15-30 litres) of water overnight, although, frustratingly for the clinician, some healthy horses will drink well in excess of this — for reasons that are unknown. Additional tests may be necessary to rule out problems.
It is possible to fit an in-line meter to an automatic waterer to monitor intake. Some drinkers incorporate a meter in the float chamber, with a small digital display on top.
Reduced intake
A horse may not be drinking enough for several reasons. If he is ill, he will usually show other signs. There may be an interruption to the water supply, perhaps because the pipes are frozen, or very low water pressure that means the refill rate is slow. Perhaps the drinker has become fouled, or the water is very cold.
Insufficient intake can predispose the horse to impaction colic. To compensate for dehydration, the horse absorbs more water from the large colon, drying the intestinal contents and causing an obstruction.
Refreshment on tap
Studies have shown that horses drink more from large-volume drinkers than small ones, where they don’t have to wait for them to refill. A study comparing water intake from a small-volume drinker supplied at three water-flow rates showed a big reduction in intake where the water pressure was low compared to high.
A drinker that holds 16 litres (equivalent to a full bucket) is preferred to a small-volume one (many hold only two to three litres). A nose-activated drinker may be used, but only if the water pressure is good and the horse learns to use it — and some horses never learn.
Some find the noise of drinkers refilling frightening. If water pressure is gradually increased by slowly opening the isolating tap, the horse may become accustomed to the sound.
Ref Horse & Hound; 13 December 2018
