In the wild, horses have 18 hours of grazing
Lie down, look at abdomen, sweat, pain, kicking, mucous membranes red
colic depends on the cause
Spasmodic colic is usually due to gas or intestinal obstruction from ingestion
of wood shavings, eating too fast, not drinking much water
Children will gain more confidence if they learn how to ride. Some pictures of the beautiful riding ponies said to be from Argentina.
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| During the day, healthy horses in a stable with many horses seldom lie down for long time. | A healthy pony is interested in the surroundings and neighbouring horses during day time. The noon feeding time was near. |
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| Transit fever after a long journey from overseas affected one horse out of twenty in this case at the quarantine. The horse would lie down a lot of time and would not drink water. No stools had been passed for 3 days. Colic would considered by the stable manager | He asked me to bring my stomach tube and laxative paraffiin oil to treat this pony. It did not need the laxative. It recovered after one antibiotic and antispasmodic injection. It passed stools soon and did not lie down anymore. |
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| Horse rolling box are useful for colicky horses to roll in the sand. It is circular in shape and so the horse's leg does not get trapped in corners when it rolls in pain. ------------------------------------------- Auscultation[edit]Auscultation of the abdomen is subjective and non-specific, but can be useful.[37] Auscultation typically is performed in a four-quadrant approach:
Each quadrant should ideally be listened to for 2 minutes. Gut sounds (borborygmi) correlate to motility of the bowel, and care should be taken to note intensity, frequency, and location.[37] Increased gut sounds (hyper-motility) may be indicative of spasmodic colic. Decreased sound, or no sound, may be suggestive of serious changes such as ileus or ischemia,[39] and persistence of hypomotile bowel often suggests the need for surgical intervention.[26] Gut sounds that occur concurrently with pain may indicate obstruction of the intestinal lumen.[39] Sounds of gas can occur with ileus, and those of fluid are associated with diarrhea which may occur with colitis.[39] Sand may sometimes be heard on the ventral midline, presenting a typical "waves on the beach" sound in a horse with sand colic after the lower abdomen is forcefully pushed with a fist.[15] Abdominal percussion ("pinging") can sometimes be used to determine if there is gas distention in the bowel.[37] This may be useful to help determine the need for trocarization, either of the cecum or the colon.[39] --------------------------------------------------- Clinical signs[edit]Clinical signs of colic are usually referable to pain, although the horse may appear depressed rather than painful in cases of necrosis (tissue death) of the gastrointestinal tract, inflammation of the intestines, endotoxemia, or significant dehydration.[45] Pain levels are often used to determine the need for surgery (See Surgical intervention). Horses are more likely to require surgery if they display severe clinical signs that can not be controlled by the administration of analgesics and sedatives, or have persistent signs that require multiple administrations of such drugs.[26] Heart rate is often used as a measure of the animal's pain level and a heart rate >60 bpm is more likely to require surgery.[23] However, this measure can be deceiving in the early stages of a severe colic, when the horse may still retain a relatively low rate.[26] Additionally, pain tolerance of the individual must be taken into account, since very stoic animals with severe cases of colic may not show adequate levels of pain to suggest the need for surgery.[9] High heart rates (>60 bpm), prolonged capillary refill time (CRT), and congested mucous membranes suggest cardiovascular compromise and the need for more intense management.[26] Decreased or absent gut sounds often suggest the need for surgical intervention if prolonged.[9][26][46] A horse showing severe clinical signs, followed by a rapid and significant improvement, may have experienced gastrointestinal perforation.[45] While this releases the pressure that originally caused so much discomfort for the horse, it results in a non-treatable peritonitis that requires euthanasia. Soon after this apparent improvement, the horse will display signs of shock, including an elevated heart rate, increased capillary refill time, rapid shallow breathing, and a change in mucous membrane color. It may also be pyretic, act depressed, or become extremely painful.[42] Gas distention usually produces mild clinical signs, but in some cases leads to severe signs due to pressure and tension on the mesentery.[45] Simple obstructions often present with a slightly elevated heart rate (<60 bpm) but normal CRT and mucous membrane color.[9] Strangulating obstructions are usually extremely painful, and the horse may have abdominal distention, congested mucous membranes, altered capillary refill time, and other signs of endotoxemia.[9] General[edit]
Medical management[edit]Colic may be managed medically or surgically. Severe clinical signs often suggest the need for surgery, especially if they can not be controlled with analgesics.[26] Immediate surgical intervention may be required, but surgery can be counter-indicated in some cases of colic, so diagnostic tests are used to help discover the cause of the colic and guide the practitioner in determining the need for surgery (See Diagnosis). The majority of colics (approximately 90%)[9] can be successfully managed medically. Analgesia and sedation[edit]The intensity of medical management is dependent on the severity of the colic, its cause, and the financial capabilities of the owner. At the most basic level, analgesia and sedation is administered to the horse. The most commonly used analgesics for colic pain in horses are NSAIDs, such as flunixin meglumine, although opioids such as butorphanol may be used if the pain is more severe.[39] Butrophanol is often given with alpha-2 agonists such as xylazine and detomidine to prolong the analgesic effects of the opioid.[39] Early colic signs may be masked with the use of NSAIDs, so some practitioners prefer to examine the horse before they are given by the owner. Nasogastric intubation and gastric decompression[edit]Nasogastric intubation, a mainstay of colic management, is often repeated multiple times until resolution of clinical signs, both as a method of gastric reflux removal and as a way to directly administer fluids and medication into the stomach. Reflux must be removed periodically to prevent distention and possible rupture of the stomach, and to track reflux production, which aids in monitoring the progression of the colic. Its use is especially important in the case of strangulating obstruction or enteritis, since both of these cause excessive secretion of fluid into the intestine, leading to fluid back-up and distention of the stomach. Nasogastric intubation also has the benefit of providing pain relief resulting from gastric distention.[39] Fluid support[edit]Fluids are commonly given, either orally by nasogastric tube or by intravenous catheter, to restore proper hydration and electrolyte balance. In cases of strangulating obstruction or enteritis, the intestine will have decreased absorption and increased secretion of fluid into the intestinal lumen, making oral fluids ineffective and possibly dangerous if they cause gastric distention and rupture.[39] This process of secretion into the intestinal lumen leads to dehydration, and these horse require large amounts of IV fluids to prevent hypotension and subsequent cardiovascular collapse. Fluid rates are calculated by adding the fluid lost during each collection of gastric reflux to the daily maintenance requirement of the horse. Due to the fact that horses absorb water in the cecum and colon, the IV fluid requirement of horses with simple obstruction is dependent on the location of the obstruction. Those that are obstructed further distally, such as at the pelvic flexure, are able to absorb more oral fluid than those obstructed in the small intestine, and therefore require less IV fluid support. Impactions are usually managed with fluids for 3–5 days before surgery is considered.[39] Fluids are given based on results of the physical examination, such as mucous membrane quality, PCV, and electrolyte levels.[39] Horses in circulatory shock, such as those suffering from endotoxemia, require very high rates of IV fluid administration. Oral fluids via nasogastric tube are often given in the case of impactions to help lubricate the obstruction. Oral fluids should not be given if significant amounts of nasogastric reflux are obtained.[39] Access to food and water will often be denied to allow careful monitoring and administration of what is taken in by the horse. Intestinal lubricants and laxatives[edit]In addition to fluid support, impactions are often treated with intestinal lubricants and laxatives to help move the obstruction along. Mineral oil is the most commonly used lubricant for large colon impactions, and is administered via nasogastric tube, up to 4 liters once or twice daily.[39] It helps coat the intestine, but is not very effective for severe impactions or sand colic since it may simply bypass the obstruction.[39] Mineral oil has the added benefit of crudely measuring GI transit time, a process which normally takes around 18 hours,[9] since it is obvious when it is passed. The detergent dioctyl sodium sulfosuccinate (DDS) is also commonly given in oral fluids. It is more effective in softening an impaction than mineral oil,[39] and helps stimulate intestinal motility,[9] but can inhibit fluid absorption from the intestine and is potentially toxic so is only given in small amounts, two separate times 48 hours apart.[39] Epsom salts are also useful for impactions, since they act both as an osmotic agent, to increase fluid in the GI tract, and as a laxative, but do run the risk of dehydration and diarrhea.[39] Strong laxatives are not recommended for treating impactions.[39] Nutritional support[edit]Horses are withheld feed when colic signs are referable to gastrointestinal disease. In long-standing cases, parenteral nutrition may be instituted. Once clinical signs improve, the horse will slowly be re-fed (introduced back to its normal diet), while being carefully monitored for pain. Endotoxemia prevention[edit]Endotoxemia is a serious complication of colic and warrants aggressive treatment. Endotoxin (lipopolysaccharide) is released from the cell wall of gram-negative bacteria when they die. Normally, endotoxin is prevented from entering systemic circulation by the barrier function of the intestinal mucosa, antibodies and enzymes which bind and neutralize it and, for the small amount that manages to enter the blood stream, removal by Kupffer cells in the liver.[5] Endotoxemia occurs when there is an overgrowth and secondary die-off of gram negative bacteria, releasing mass quantities of endotoxin. This is especially common when the mucosal barrier is damaged, as with ischemia of the GI tract secondary to a strangulating lesion or displacement.[5] Endotoxemia produces systemic effects such as cardiovascular shock, insulin resistance, and coagulation abnormalities.[3][39] Fluid support is essential to maintain blood pressure, often with the help of colloids or hypertonic saline. NSAIDs are commonly given to reduce systemic inflammation. However, they decrease the levels of certain prostaglandins that normally promote healing of the intestinal mucosa, which subsequently increases the amount of endotoxin absorbed. To counteract this, NSAIDs are sometimes administered with a lidocaine drip, which appears to reduce this particular negative effect.[5] Flunixin may be used for this purpose at a dose lower than that used for analgesia, so can be safely given to a colicky horse without risking masking signs that the horse requires surgery.[39] Other drugs that bind endotoxin, such as polymyxin B and Bio-Sponge, are also often used.[5] Polymixin B prevents endotoxin from binding to inflammatory cells, but is potentially nephrotoxic, so should be used with caution in horses with azotemia, especially neonatal foals. Plasma may also be given with the intent of neutralizing endotoxin.[39] Laminitis is a major concern in horses suffering from endotoxemia. Ideally, prophylactic treatment should be provided to endotoxic horses, which includes the use of NSAIDs, DMSO, icing of the feet, and frog support.[3] Horses are also sometimes administered heparin, which is thought to reduce the risk of laminitis by decreasing blood coagulability and thus blood clot formation in the capillaries of the foot.[5] Case-specific drug treatment[edit]Specific causes of colic are best managed with certain drugs. These include:
Surgical interventionSurgical intervention[edit]Surgery poses significant expense and risks, including peritonitis, the formation of adhesions, complications secondary to general anesthesia, injury upon recovery of the horse which may require euthanasia, dehiscence, or infection of the incisional site. Additionally, surgical cases may develop post-operative ileus which requires further medical management.[2] However, surgery may be required to save the life of the horse, and 1–2% of all colics require surgical intervention.[3] If a section of intestine is significantly damaged, it may need to be removed (resection) and the healthy parts reattached together (anastomosis). Horses may have up to 80% of their intestines removed and still function normally, without needing a special diet.[9] Survival rates[edit]In the case of colics requiring surgery, survival rates are best improved by quick recognition of colic and immediate surgical referral, rather than waiting to see if the horse improves, which only increases the extent of intestinal compromise.[3] Survival rates are higher in surgical cases that do not require resection and anastomosis. 90% of large intestinal colic surgeries that are not due to volvulus, and 20–80% of large colon volvuluses, are discharged; while 85–90% of non strangulating small intestinal lesions, and 65–75% of strangulating intestinal lesions are discharged.[3] 10–20% of small intestinal surgical cases require a second surgery, while only 5% of large intestinal cases do so.[3] Horses that survive colic surgery have a high rate of return to athletic function. According to one study, approximately 86% of horses discharged returned to work, and 83.5% returned to same or better performance.[3] Adhesion formation[edit]Adhesions, or scar tissue between various organs that are not normally attached within the abdomen, may occur whenever an abdominal surgery is performed. It is often seen secondary to reperfusion injury where there is ischemic bowel or after intestinal distention.[13][47] This injury causes neutrophils to move into the serosa and mesothelium to be lost, which the body then attempts to repair using fibrin and collagen, leading to adhesion formation between adjacent tissues with either fibrinous or fibrous material.[13] Adhesions may encourage a volvulus, as the attachment provides a pivot point, or force a tight turn between two adjacent loops that are now attached, leading to partial obstruction. For this reason, clinical signs vary from silent lesions to acute obstruction,[13] encouraging future colics including intestinal obstruction or strangulation,[48] and requiring further surgery and risk of adhesion.[6] Generally, adhesions form within the first two months following surgery.[13] Adhesions occur most commonly in horses with small intestinal disease (22% of all surgical colics), foals (17%), those requiring enterotomy or a resection and anastomosis, or those that develop septic peritonitis.[13] Prevention of adhesions begins with good surgical technique to minimize trauma to the tissue and thus reparative responses by the body. Several drugs and substances are used to try to prevent adhesion formation. Preoperative use of DMSO, a free radical scavenger, potassium penicillin, and flunixin meglumine may be given. The thick intestinal lubricant carboxymethylcellulose[2] is often applied to the GI tract intraoperatively, to decrease trauma from handling by the surgeon and provide a physical barrier between the intestine and adjacent intestinal loops or abdominal organs. It has been shown to double the survival rate of horses, and its use is now a standard practice.[6] Hyaluraonan can also be used to produce a physical barrier.[13] Intraperitoneal unfractionated heparin is sometimes used, since it decreases fibrin formation and thus may decrease fibrinous adhesions.[6] Omentectomy (removal of the omentum) is a quick, simple procedure that also greatly decreases the risk of adhesions, since the omentum is one organ that commonly adheres to the intestines.[6] The abdomen is usually lavaged copiously before the abdomen is sutured closed, and anti-inflammatories are given postoperatively.[3] A laparoscope may be used post-surgery to look for and break down adhesions, however there is risk of additional adhesions forming post-procedure.[48] Encouraging motility post-surgery can also be useful, as it decreases the contact time between tissues.[13] Adhesion-induced colic has a poor prognosis, with a 16% survival rate in one study.[13] Post-operative care[edit]Small amounts of food is usually introduced as soon as possible after surgery, usually within 18–36 hours,[36] to encourage motility and reduce the risk of ileus and the formation of adhesions.[2][3] Often horses are stall rested with short bouts of hand walking to encourage intestinal motility.[3] The incision site is carefully monitored for dehiscence, or complete failure of the incision leading to spillage of the abdominal contents out of the incision site,[6] and the horse is not allowed turn-out until the incision has healed, usually after 30 days of stall rest. Abdominal bandages are sometimes used to help prevent the risk of dehiscence.[6] Incisional infection doubles the time required for postoperative care, and dehiscence may lead to intestinal herniation, which reduces the likelihood of return to athletic function.[3] Therefore, antibiotics are given 2–3 days after surgery, and temperature is constantly monitored, to help assess if an infection is present. Antibiotics are not used long-term due to the risk of antimicrobial resistance.[36] The incision usually takes 6 months to reach 80% strength, while intestinal healing following resection and anastomosis is much faster, at a rate to 100% strength in 3 weeks.[3] After the incision has healed adequately, the horse is turned out in a small area for another 2–3 months, and light exercise is added to improve the tone and strength of the abdominal musculature. Weight loss of 75–100 pounds is common after colic surgery, secondary to the decreased function of the gastrointestinal tract and from muscle atrophy that occurs while the horse is rested.[3] This weight is often rapidly replaced. Draft horses tend to have more difficulty post-surgery because they are often under anesthesia for a longer period of time, since they have a greater amount of gastrointestinal tract to evaluate, and their increased size places more pressure on their musculature, which can lead to muscle damage. Miniature horses and fat ponies are at increased risk for hepatic lipidosis post-surgery,[36] a serious complication. Prevention[edit]The incidence of colic can be reduced by restricted access to simple carbohydrates[12] including sugars from feeds with excessive molasses, providing clean feed and drinking water, preventing the ingestion of dirt or sand by using an elevated feeding surface, a regular feeding schedule, regular deworming, regular dental care, a regular diet that does not change substantially in content or proportion and prevention of heatstroke. Horses that bolt their feed are at risk of colic, and several management techniques may be used to slow down the rate of feed consumption. Supplementing with previously mentioned form of pysllium fiber may reduce risk of sand colic if in a high-risk area. Most supplement forms are given one week per month and available wherever equine feed is purchased. Turnout is thought to reduce the likelihood of colic, although this has not been proven.[12][49] It is recommended that a horse receive ideally 18 hours of grazing time each day,[49] as in the wild. However, many times this is difficult to manage with competition horses and those that are boarded, as well as for animals that are easy keepers with access to lush pasture and hence at risk of laminitis. Turnout on a dry lot with lower-quality fodder may have similar beneficial effects. |
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