Q: I own a six-year-old cob mare and her four-month-old foal, and they are both doing well. I keepthem at DIY livery and they live out on five acres. However, the soil is quite sandy, and with my grazing being poor I am worried about sand colic. Can you tell me what happens if a horse gets sand colic and can I help to prevent it in any way?
Jo Holmes MRCVS replies: Horses grazing on sandy locations inevitably ingest sand, and younger horses are more likely to over-ingest as they tend to be less fussy about what they eat.
Sand will irritate the large colon, causing inflammation of the gut wall, which leads to either chronic diarrhoea or an impaction blocking the gut.
To help avoid this problem, make sure that your horse is fed any hard feed from buckets or mangers, not from the ground.
Under direction from your vet, you can give your horse Psyllium in his feed once a day. This is a powder which is designed to get between sand particles and break them up. Beware of giving Psyllium long term, as its effectiveness can diminish over time, as gut microbes adapt to it.
Feeding a high-fibre diet is also essential to maintain gut mobility. Provide hay in the field if the pasture becomes too poor, preferably in haynets which are tied high enough to avoid legs getting caught.
If you suspect sand as the cause of a gastric problem in your horse, dissolve some of his faeces in a bucket of water. Any sand in the faeces will sink to the bottom, so establishing its presence.
The amount obtained should be compared with a sample taken from a healthy horse in the same location, to assess what is a normal, acceptable level in the faeces, as sand may not necessarily be the cause of the problem.
X-rays can reveal sand impactions in foals and ponies, and diagnostic ultrasound may reveal it in larger horses.
If there is an impaction, your vet may prescribe laxatives which will lubricate the gut and help to move sand through it without damaging the gut lining further.
In acute cases, your vet may administerPsyllium dissolved in water via a stomach tube. This may need to be repeated several times a day by your vet for many days until the obstruction is cleared.