Colic occurs in horses worldwide. However, there are certain risk factors. For example, it has been observed that colic is more common in Arabian horses than in racehorses. Horses with inconsistent water intake are also more susceptible than those with unlimited access (Reeves et al., 1996; Curtis et al., 2019). Increased risk is also observed in horses fed whole corn, horses with severe dental problems, those with stereotypic behaviors or those having received an anthelmintic within 6 months (Salem et al., 2017). However, horses that are dewormed regularly are less prone to colic (Reeves et al., 1996; Curtis et al., 2019). Age, diet, and the person caring for the horse also play a role (Reeves et al., 1996; Curtis et al., 2019).

Although colic is mainly associated with digestive causes, abdominal pain can also be caused by various other pathologies. Therefore, it is important not to overlook abdominal pain related to the renal, urinary, reproductive systems, and others. Digestive colic can be classified according to its cause, the target organ and its duration. Among these causes we find:

• Simple obstructions
  • Such as spasms, gas, impaction, sand, enteroliths and worms
• Strangulated obstructions of the small or large intestine
  • Such as entrapment in the epiploic foramen, entrapment in a mesenteric hole or even pedunculated lipoma
• Non-strangulated infarctions
• Ulcerations or inflammatory diseases
  • Such as ulcers, enteritis or colitis

The target organ can be the:

• Stomach
  • Such as gastric ulcers, impaction (food accumulation) or dilation of the stomach
• Small intestine
  • Such as tympanism (gas), impaction, strangulation (e.g. hernia) or even an infarction
• Colon
  • Impactions are frequent as well as colitis
• Cecum
  • Such as tympanic (gas) or impaction

Finally, the cecum can be tympanic or impacted as well. Colic is defined by its duration and can therefore be acute (less than 36 hours of pain), chronic (more than 36 hours), or recurrent (if colic episodes occur regularly) (Ragab, 2023).

Symptoms

Horse owners are often aware of the signs that horses may exhibit during colic. Abdominal pain is manifested by visible behavioral changes: the horse turns in small circles, lies down and gets up constantly, kicks its belly, looks at its flanks, rolls or gets stuck on its back (Rhodes and Madrigal, 2021). Male may have its penis out without urinating or urinating small amounts. Horses may also play with water without really drinking (Dukti , 2012; van Loon and Van Dierendonck , 2015; Constable et al., 2017; Mair and Sherlock, 2023; Talbot et al., 2023). A camped position may be observed. The same is true for a swollen abdomen (Constable et al., 2017; Mair and Sherlock, 2023). The first thing to do when you notice these symptoms is to call your veterinarian. This is a life-threatening emergency.

Diagnosis

The veterinarian will conduct a complete emergency examination. Which includes:

• Heart rate
  They will check the heart rate, which increases significantly in painful horses and is a good indicator of the severity of the condition (Stashak, 1979; Dukti, 2012).
• Mucous membranes
  The mucous membranes will also be observed. They should be pink, moist and with a capillary refill time after finger pressure on the mucous membrane of less than 2 seconds. In a horse with colic, they could be red, blue, dry, etc. (Constable et al., 2017; Rhodes and Madrigal, 2021).
• Sweating
  Sweating is also common with cold extremities (Constable et al., 2017).
• Abdominal sounds
  The veterinarian will also auscultate the abdomen in its 4 quadrants, listening to the strength, frequency and nature of the abdominal sounds. In a horse with colic, these sounds will be reduced or even absent. Conversely, in a horse with diarrhea, they could be increased (Constable et al., 2017; Rhodes and Madrigal, 2021; Mair and Sherlock, 2023).
• Rectal palpation
  Afterwards, he will perform a rectal palpation which will help find the cause of the colic (Constable et al., 2017; Mair and Sherlock, 2023). A nasogastric tubing should also be performed routinely, we will detail it in the treatment section where it also plays a role (Constable et al., 2017; Mair and Sherlock, 2023). Performing an abdominal ultrasound is more reserved for equine clinics and, with transrectal palpation, will allow the cause of colic to be identified (Busoni et al., 2011; le Jeune and Whitcomb , 2014; Constable et al., 2017; Rhodes and Madrigal, 2021; Mair and Sherlock, 2023).
• Blood tests
  Clinic veterinarians will also do a complete blood test to see the state of hydration for example.
• X-rays
  X-rays are taken in certain specific cases to check for the absence of sand in the intestines, which can also be a cause of colic.

Treatment of equine colic

Medical treatment at home is sufficient in most cases. However, some more advanced cases will require hospitalization. Medical treatment includes several approaches: fasting, movement, pain reduction, restoration of body fluids, gastrointestinal lubrication and finally treatment of underlying diseases. Fasting is essential while the colic resolves, followed by gradual refeeding. The horse will also be walked or sometimes trotted in order to stimulate intestinal transit. Pain reduction will be done with painkillers that are generally not very powerful so as not to mask the symptoms or antispasmodics. Fluid restoration consists of placing an intravenous catheter and administering fluids. Concerning gastrointestinal lubrication, it is done by nasogastric intubation. Nasogastric tubing serves both as a diagnosis and a treatment. It gives us important information. It allows the stomach to be emptied, which can save the horse’s life, as it cannot vomit, and it is through this tube that paraffin or electrolytes can be administered to facilitate the evacuation of intestinal contents. The treatment of underlying diseases varies greatly. For example, colic caused by stomach ulcers will be treated by administering medication and an appropriate diet. For sand in the digestive tract, psyllium will then be administered.In some cases, if all other treatments are insufficient, emergency surgery will be necessary to address the cause of colic (Dukti, 2012; Constable et al., 2017; Rhodes and Madrigal, 2021; Mair and Sherlock, 2023).

Prevention colic in horses

Since colic can be fatal, prevention is therefore a key point. It is advisable to carry out regular exercise with a limitation of the time spent in the box, to have a balanced diet with good quality hay (without mold for example), to have access to clear and fresh water at any time of the day. In the event of a change of diet, do so gradually over about 10 days. Prevent the ingestion of sand or straw. In addition, avoid stressful conditions such as transport (with regular breaks to allow hydration and feeding), or extreme temperatures. Finally, regular veterinary monitoring with vaccination, dental care and deworming is essential (Dukti , 2012; Constable et al., 2017; Rhodes and Madrigal, 2021; Mair and Sherlock, 2023).

Colic and nutrition

As mentioned above, nutrition plays a major role in preventing colic. Be careful, the practices recommended for one type of colic are not necessarily suitable for another type (Hassel et al 2008). A nutritionist will therefore be able to help you with the process. However, in some horses with recurrent colic of unidentified cause, general advice can be applied. Putting out to pasture is suitable, but you should be aware of the fructans level in the grass. These could reach the large intestine and cause fermentation. Opt for high-quality forage with free access. When the horse has higher needs and requires an energy supplement, highly fermentable fibers such as beet pulp or cut alfalfa are favored. If this is not enough to meet the energy needs, you can choose a small quantity of highly digestible starch (oats for example) or vegetable oil. Generally, avoid high-starch foods, as they may exceed the small intestine’s capacity to digest starch (the same counts for fructans), leading to fermentation in the large intestine, producing gas and lactic acid. Lactic acid can harm beneficial intestinal bacteria. When feeding starch rich feeds, small meals spread throughout the day are preferred over single large meals to reduce the sugar level per meal.

There are a good number of high-fibre, low-starch horse feeds on the market. Since Hartog feeds are naturally high in fibers, many of their products are suitable for horses sensitive to colic. If your horse has low energy requirements, it is advisable to provide Hartog Compact Grass as quality forage combined with Hartog Essential which is molasses-free, cereal-free and low in sugar and starch in order to balance the ration in vitamins, minerals and trace elements. If on the contrary the horse requires an energy supplement, due to its work for example, it would be wise to supplement the Hartog Compact Grass with the Hartog Comfort which has the same characteristics as Hartog Essential but also contains forage and a higher energy value. In addition, Hartog Digest is specially designed to support the digestive system with postbiotics, magnesium, alfalfa and linseed oil. Some feed supplements can also help with microbiome health such as probiotics based on saccharomyces or FOS (fructooligosaccharides). Note that refeeding after surgical colic is very specific and will be managed by the clinic (Geor, Harris and Coenen, 2013).

Conclusion equine colic

The anatomical, behavioral and physiological characteristics of horses make them sensitive to colic. It is a serious condition that should be addressed promptly. It is important to recognize the symptoms to be able to call the veterinarian quickly. Colic can be fatal. Most of the time they will pass with a medical treatment but some cases require a surgical approach. Prevention remains the best approach, particularly through appropriate nutrition.

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