Sand colic and what to do if your horse has colic

It can be distressing to see a horse with colic, and sometimes the most simple things can be the cause – sand, for example. DR CAT MARSDEN explains.

The term ‘colic’ simply means abdominal pain. There are multiple causes, including sand impaction or sand enteropathy, which is of particular significance in coastal locations and in dry areas with poor vegetation growth. Sand colic is caused by an accumulation of sand in the gastrointestinal tract, which may occur if your horse is ingesting sand while eating hay off the ground, is grazing in sandy pastures, or drinking from shallow mud puddles. Sand can cause irritation, intermittent colic, and sometimes complete obstruction.

Symptoms

Sand colic may manifest in one of two clinical ways: diarrhoea and/or impaction.

Diarrhoea: Diarrhoea is caused through mucosal inflammation caused by constant abrasion by the sand within the lumen (the interior space) of the bowel. This constant irritation and abrasion results in a reduction of the absorptive surface of the bowel, thus causing chronic diarrhoea and weight loss. These horses are often colicky intermittently. Notably, the colic symptoms often occur when the horse is producing manure of a normal consistency. This is significant in regard to diagnosis as with other causes of diarrhoea, the horse is colicky at or around the time of diarrhoea production.

Impaction: Colic symptoms associated with sand impaction colic are typically secondary to tension on the mesentery (the tissue that connects abdominal contents to the body wall) due to the weight of sand within the bowel. In chronic cases, horses may show low grade colic symptoms intermittently, including standing stretched out, lying on their side, or flank watching. Symptoms of colic can appear more acute/severe in cases where the colon becomes obstructed, torsed (twisted) or displaced because of the chronic sand accumulation.

How is sand colic diagnosed?

There are a number of ways your vet may diagnose sand colic; however, the simplest way is to perform a faecal sand sediment test. This involves taking three to four faecal balls and soaking them in water within a rectal palpation glove. Because sand is heavier, it will settle in the fingers of the glove while the remaining matter and water will sit on top. More than 1 teaspoon of sand per four faecal balls is considered evidence of sand accumulation.

Additionally, rectal palpation or diagnostic imaging (ultrasound or xray) can be used to determine whether or not there is an accumulation of sand.

How is it treated?

Sand colic can be treated through either medical or surgical management.

Medical management: The aim when treating sand colic involves managing pain and inflammation, and lubricating and disrupting the obstructing mass. Medical management of sand colic typically involves administering pain relief in the form of flunixin intravenously and dosing the patient with psyllium husk orally or through a nasogastric tube.

Psyllium has the ability to penetrate, hydrate and disrupt sand impactions, thereby allowing the sand to be passed in the faeces. If psyllium is ineffective in resolving the impaction, magnesium sulfate in combination with mineral oil and administered through a nasogastric tube may be effective.

Surgical management: In cases where the horse does not respond to medical management, or for horses who are in acute and uncontrollable pain, surgical intervention may be required to physically remove the sand.

Prevention – the best option

Prevention is key to managing sand colic, and reducing your horse’s access to sand is the obvious starting point. Ideally, a horse should be fed off the ground, but if restricting access to sandy ground is not possible, using hay nets or deep feed tubs are both options. In addition, feeding horses on rubber or concrete surfaces ensures that any feed that is dropped will not be eaten with a side of sand. Remember to clean the mats and tubs regularly and always provide good quality feed.

Feeding plenty of forage can help to move sand through the digestive tract before it settles, and maintaining healthy pastures is also important. Avoid overgrazing as horses may consume more sand when eating short grass.

It has also been suggested that feeding psyllium for five to seven consecutive days each month may reduce the incidence of sand accumulation by helping to keep it passing through the GI tract. However, this should be done in addition to and not in place of other management strategies.

I think my horse has colic

Key to helping you identify any abnormality in your horse’s health, is being aware of what is normal for them. It is important to have observed and noted their normal eating habits, their faecal output and consistency, and knowing their usual temperature, pulse and respiration rate (TPR) is vital in identifying whether something is abnormal before it becomes an emergency.

So, if you think your horse has colic, there are some basic procedures which would be helpful to implement:

Check your horse’s vital signs: A normal heart rate is between 32 to 40 beats per minute; a normal respiratory rate should be between 8 to 20 breaths per minutes; and a normal temperature can range from 36.9ºC to 38.5ºC. Monitor your horse’s vital signs, in addition to any other clinical signs (pawing, rolling, stretching). This information will allow you to give your vet an idea of the duration of the problem, and whether your horse’s symptoms have deteriorated over time.

Never medicate without your vet’s approval: Medicating your horse prior to your vet’s arrival is problematic in two ways:

• It limits what drugs your vet can use (e.g. If you’ve given bute, your vet can’t use flunixin, which is a much more potent and effective drug for colic)
• Medication may mask the symptoms of pain and thus make it more difficult for your vet to adequately assess and diagnose your horse.

Call the vet: Regardless of the severity of the symptoms of colic, it is always best to get your vet to come and attend your horse. If managed promptly and appropriately, your vet may be able to prevent a simple colic snowballing into something worse.

Look for poo: Take note of the number of poos and their consistency (are they very hard, a bit loose, big or small). This will help give your vet a clue as to why your horse may be colicky

Prepare for your vet’s arrival: While you’re waiting for your vet to arrive, there are a number of things you can do to prepare:

• Carefully consider what may have changed in the hours and days preceding the colic. Have you changed feed (new hay, new pellets, new pasture)? Has the horse been wormed recently? Are there weeds in the paddock?
• Remove all feed from your horse. It is best to place the horse in a small yard with fresh water and no feed prior to your vet’s arrival
• Walk your horse if it is actively colicking. This can assist to move gas through the gastrointestinal tract and will also prevent the horse from rolling.
• Ensure that you have a bucket of fresh water and a safe, well-lit area for your horse to be examined when the vet arrives.

Plan ahead: Sometimes colic cannot be managed at home and may require the horse to go to a referral hospital. It is important that if referral is an option that you have a plan for transporting your horse safely.

Dr Cat Marsden’s particular interests are in equine sports medicine, lameness and reproduction. She can be found at the Southwest Equine Veterinary Group in Warrnambool VIC.