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Equine Colic

Those diseases of the horse, which cause abdominal pain, are generally called equine Colic.
The word "colic" is nonspecific, and simply refers to the manifestation of visceral abdominal pain.

Classification the cause of colic as:

Obstructive.
Obstructive and strangulating.
Nonstrangulating infarctive.
Inflammatory ( peritonitis , enteritis) .

There are some risk factors associated with colic that owners however, can impact on, including:
Worm control heavy worm burdens increase the risk of colic.
Dietary change rapid dietary change increases the risk of colic.
Dental health poor dentition is associated with impaction colic.
Roughage quality Diets predominately containing coarse roughage (such as straw) are associated with impaction colic.

Colic cases can also be classified on the basis of the duration of the disease:

Acute colic : ( 24-36 h).
Gastric dilation, ilecoaecal valve impaction, intestinal emergency colic (Intussuception-volvolus-strangulation) diaphragmatic hernia, enterolith, enteritis flatulent colic and hemorrhage.
Subacute colic :
Impaction of colon, caecum, spasmodic colic and retained meconium.
Chronic colic (> 24-36 h) :
Mesenteric Verminus arteritis constriction of gut by adhesion and peritonitis.
Recurrent colic: multiple episodes separated by periods of > 2 days of normality).
The most common recurrent colic is simple impaction of caecum and colon due to poor condition of molar teeth, too frequent heavy feed and debilitated old age animals.


Colic cases can also be classified on the basis of the causes of colic

Gas Colic

Gas colic occurs when there is excessive build up of gas within the intestines of the horse. These horses can often have a lot of flatulence.
Spasmodic Colic
Spasmodic colic is the result of intestinal cramps or spasms. This type of colic can also have intestinal hyper motility.
Impaction Colic
Impaction colic accounts for 10% of all colics attended by veterinarians. These occur where partially digested feed, typically roughage, builds up in the large intestine of the horse and stops moving, resulting in a blockage or impaction. With impaction colic, the horse is not passing dung.
Sand Colic
Sand colic occurs in horses living in sandy areas, or horses fed from sandy ground. Fine particle sand builds up in the large intestines resulting in colic.
Twisted Gut
A twisted gut occurs where a portion of the intestine twists on itself (intestinal torsion) or where a portion of intestine inverts into itself (intussusception). This uncommon type of colic accounts for less than 4% of colics overall, but it is very serious and life threatening.
Strangulation Colic
Strangulation colic is very uncommon, but very serious. Strangulation colic occurs when the blood supply to an area of intestines is cut off (strangulated). Cutting off the blood supply, results in rapid death of the intestine wall, a serious life threatening situation.

There are three primary modes of colic in horses:

1. Distention and/or obstruction of the gut with fluid, gas, ingesta or foreign
bodies.
2. Tension on the mesenteric root such as that caused by twisting of the
intestine.
3. Ischemia or infarction as may be caused by parasite damage, or
intestinal torsion/volvulus.


The most prominent feature is distention.
This may be:
(1) Static (physical colic) when there is an accumulation of ingesta-gas or fluid.(2) Or transient (Functional) when local, periodic distention occurs as the result of
spasm with increased peristalsis of the intestinal segments.(3) Stretching of the peritoneum.

Clinical signs:1- Pain is manifested by looking at the flank, rolling, lying down on the back
(careful in lying down and getting up). The horse often sitting, like a dog.
, protrude the penis without urination.2- Pain is generally subacute or acute. It is intermittent in early stages and the
severity is correlated with the severity of the illness. In most severe cases the pain
is almost continuous.
3- Restlessness manifested by pawing & kicking at the belly or by sitting, getting
up and lying down frequently.4- Obvious signs of shock, profuse sweating with elevated heart and respiratory
rates, prolonged capillary refill time, cold extremities

The Veterinary Colic Exam

The colic examination is a complex evaluation of a multitude of interacting factors with many differing variables.
The following is a brief overview of some of the parameters that your veterinarians will asses and some of the procedures they may perform.
Heart Rate: An elevated heart rate is usually a good indicator of pain and can often be an indicator of severity of colic.
A normal resting heart rate is around 28-40 beats per minute.

Mucous Membranes and Capillary Refill Time: Your veterinarian will look at the colour and moistness of your horses gums and will then asses the capillary refill time by pressing on the gums to blanch them and seeing how long it takes for colour to return.
Mucous membrane colour, moistness and capillary refill time help to assess your horses hydration status and are good indicators of blood perfusion.


Normal gums should be salmon pink, moist with a capillary refill time of less than 2 seconds.

Skin Tent: By pinching up a section of skin and seeing how quickly it returns to normal can help ascertain if your horse is dehydrated. Hydration is closely related to skin elasticity, however, the skin tent is not always very reliable and your vet will use your horses gum characteristics in association with the skin tent and other things like sunken eyes to fully gauge hydration status.

Gut Sounds: By listening to the gut sounds through a stethoscope your veterinarian can get a good indication of how much activity is occurring inside the abdomen. Your vet will usually listen to the upper left, lower left, upper right and lower right sections of the abdomen and determine what sort of gut sounds are present.
Gut sounds are broadly grouped into 4 categories; increased, normal, decreased and absent.

Rectal Examination: The rectal exam is a vital part of the colic diagnostic process as it allows the veterinarian to feel what is occurring inside the abdomen. Most horses will require sedation to perform this examination if stocks are not available. The vet will be able to assess if there are any major abnormalities present such as an impaction or if there is a distended loop of bowel due to a twist, but as you can imagine your vets arm only reaches so far forward and can only feel so much.
Passing a Nasogastric (Stomach) Tube: Passing a tube up your horses nose and down into its stomach is both diagnostic and therapeutic. Your vet is first of all looking for what is termed gastric reflux. Gastric reflux occurs when there is a blockage in the bowel (usually the small intestine) that causes the build up of fluid in front of it. Unlike other species the horse cant vomit and the stomach can rupture due to build up of fluid. The presence of gastric reflux is often a major indicator for surgery. If gastric reflux is not present, your vet may decide to administer some fluids down the tube to help treat your horses colic.

Abdominocentesis: Commonly known as a belly tap, abdominocentesis is a procedure that involves placing a needle into the abdomen to see if there is any free fluid in the abdomen. If obtained, analysis of this fluid can indicate the health of the bowel to your veterinarian.

Notice:

(1) Pulse rate less than 80/mmis favorable - a rate over 100/indicates danger.(2) Too low temp. Indicates the development of shock, while fever suggests other
cause of the signs observed.(3) Absence of peristalsis suggests paralytic ileus.(4) Gas-filled loops of intestine is an indication of flatulent colic and if
accompanied by much fluid indicates intestinal obstruction.(5) Long, unbroken columns of feces is an indication of impaction.(6) A passage of stomach tube may be necessary to detect if there is suspect of
inflammatory exudate in peritoneal cavity.
Treatment:
Generally it depends on the nature of every case and the situation of the lesion.
The following principles are recommended:1) Analgesia: To prevent self injury and without masking the use of pethidine (Meperidine) or chloral hydrate are satisfactory drugs. Synthetic analgesic is an excellent pain relief in horses (2 mg/kg b.w.).2) Evacuation of the bowel in case of impaction with fecal material is necessary by: a- Mineral oil b- Anthroquinone purgatives (much smaller in size-but variable in efficiency). c- parasympathomimetic drugs as arecolin, physostigmine and other could be
used alone or with lubricant. In very impacted colon the use of these
stimulants may cause unnecessary pain. d- Antispasmodics as atropine are to be the avoided unless there is a functional
motility.3) Treat the fluid lossfluid therapy.5) Surgical in some cases of physical colic.