In decades past, colic treatment was
actually a misnomer. "Treatment" consisted of waiting out the
colic while offering sedative-like drugs to dampen a horse's
misery. Either his body healed of its own accord, or he
succumbed to death from overwhelming pain and shock.
Veterinarians were reluctant to euthanize a horse with colic
because one could never tell if he was going to make it or not.
A serious colic crisis of an intestinal twist or unyielding
impaction was a death sentence in those times.
While colic still remains a major killer of
horses, today a surge in sophistication of medical, surgical,
and anesthetic techniques gives horses a greater chance to
survive colic than ever before. Facilities for equine abdominal
surgery exist at university veterinary teaching hospitals and in
many private clinics throughout the country.
In managing a colic crisis today, whether
in the field or at a clinic, a veterinarian has a wealth of
expertise from which educated decisions can be made. Although a
specific diagnosis is only achieved in about one-quarter of all
colic cases, information obtained from a thorough physical exam
and diagnostic procedures can hasten a decision to apply
aggressive medical intervention or to send a surgical candidate
to the operating table. For horses requiring surgery, survival
rates are directly related to the severity of the problem and
the time span between the onset of colic and surgical
correction.
To arrive at a timely diagnosis and medical
management, a coordinated team effort must be rallied between an
owner and a veterinarian, with a surgical staff on standby if
needed.
It is a helpless feeling to watch a horse
in pain and distress without being able to do anything about it
other than to call for the vet. If your horse does colic, you as
the owner have a very important role to play.
Signs to Watch For
Sensitivity to a horse's changing mood can
detect subtle and early stages of colic. Rather than waiting for
your horse to exhibit marked signs of pain, you should summon a
vet immediately upon finding your horse depressed, off feed, or
lying down at odd times or in odd postures. Obvious or
persistent expressions of pain by a horse affirms a need for
veterinary help.
A colicky horse might paw the ground, back
up for several steps, kick or bite at his belly, roll his upper
lip (flehmen), yawn repeatedly, or grind his teeth. He might
stretch as if to urinate, or turn his head as if pointing to his
abdomen. As pain progresses, a horse might lie down, get up, and
lie down again to try and relieve the agony in his belly.
Vigorous rolling on the ground, self-inflicted trauma, or a
soaking sweat are signals of severe distress, as are poor
capillary refill time or poor coloration (brick red or white) of
the gums. Prompt recognition of a problem, with immediate
administration of medical therapy, can often correct a colic
crisis before it turns into a problem requiring surgery. The
first thing to do when you notice your horse is feeling poorly
is to pick up the phone to call your veterinarian.
Interpreting Your Horse's Pain
While waiting for medical help to arrive,
you can do a few things to help your horse ignore his
discomfort. In the initial stages of colic, trotting a horse on
a longe line for 10 or 15 minutes can relieve the crisis if it
is a gaseous or spasmodic episode (sudden, violent, involuntary
contraction of a muscle or a group of muscles, attended by pain
and interference with function). You might hear him pass gas as
he trots, and hopefully after the brief exercise, he will feel
more comfortable and the crisis will be over. If severe pain is
evident during exercise, it should be discontinued.
If the horse is still painful after trying
this strategy, a horse in mild pain should be allowed to rest
quietly if he will do so, either standing or lying down. In the
old days, horse owners thought there was value in walking a
horse for hours. In fact, prolonged forced movement can be
counterproductive. Walking or trotting a horse for lengthy
periods saps valuable energy reserves needed to combat the
crisis--for both horse and owner.
Although each horse has a different
threshold for pain, intestinal pain is overbearing to any
individual, making painful signs and mental attitude valuable
diagnostic aids. If a mildly painful colic persists for more
than eight to 12 hours, or if it recurs intermittently during
that time, or if intravenous fluids and pain-relieving
medications are not correcting the problem, it is probably time
for surgery. If a horse has experienced repeated episodes of
colic with no specific diagnosis attained, it could be time for
exploratory surgery of the abdomen to identify the source of a
recurrent problem. Severe or unrelenting pain despite the
presence of pain-relieving medications makes a strong argument
for the need for surgery.
A painful horse is difficult to handle at
times as he might throw himself to the ground or roll violently
in an effort to relieve his plight. A horse like this might
require forced walking to keep him distracted and somewhat
controlled until help arrives. Due to the unpredictability and
uncontrollable nature of an extremely violent colic, stay as
clear of the horse as possible. Be attentive to the danger of
being wedged in a stall corner with the horse. Get the horse on
his feet if feasible, and move him to a large area or grassy
spot where he is least likely to inflict injury to himself and
people.
Communicating with the Vet
The greatest contribution you can make to
assist your veterinarian in arriving at a treatment plan is to
provide detailed information. Valuable information is learned
from the age, sex, breed, and previous and current geographic
location of a horse. Specific problems exist in certain areas of
the country, and age-related syndromes also occur. Examples
include sand colic in certain geographical locales, enteroliths
(intestinal stones) in certain parts of the country, lipomas
(fatty tumors) in older horses, or large colon torsions (twists)
in broodmares which have recently foaled.
Discuss the horse's diet and any recent
changes in nutrition, availability of water, exercise routines,
or recent transportation of the horse. Deworming schedules,
medications your horse currently is receiving, and past illness
or surgery are important details to tell your veterinarian. An
overview of occurrences in your horse's life in recent hours and
days is of paramount importance. Have there been any significant
changes in the horse's routine or diet? When was the last noted
bowel movement? What was its consistency? When did you last
notice your horse eating? When did your horse's demeanor change?
Pinpointing the onset of pain or its discovery defines a time
period and progression of events pertinent to decisions
regarding necessary therapy.
Colic Related to Non-Intestinal Problems
Other issues can cause a horse to look like
he is colicking when in fact his intestines are just fine. Some
examples might be the horse which is tying-up with muscle
cramps, a mare starting labor for foaling, a horse with pleuro-pneumonia
(inflammation of the lungs and the membranes covering the
lungs), or a horse which is choking. Even a horse with laminitis
might display colic-like signs. The important thing is to see if
the horse will rise from the ground, if he will eat if offered
food, and to gather all the vital signs you can so that you can
intelligently relay this information to your veterinarian when
you call.
Vital Signs
Some physical exam parameters can be
monitored by you throughout a colic ordeal, such as the horse's
degree of pain and mental attitude. Also check:
- Rectal temperature;
- Respiratory rate and character;
- Heart rate, pulse rate, and pulse
strength;
- Color and capillary refill time of
mucous membranes;
- Moistness of mucous membranes and skin
elasticity (to roughly estimate dehydration); and
- Quality and frequency of intestinal
sounds in all quadrants.
Each of these parameters is important to
the overall clinical picture. With practice, you can learn to
examine a horse and recognize when signs differ from those found
when your horse is in a normal state. A study conducted by the
Morris Animal Foundation concluded that color of the mucous
membranes has a significant relationship to survival. Because
mucous membrane color and capillary refill time reflect blood
perfusion through the body, they correlate well to development
and progression of shock. Shock is closely associated with
surgical colic syndromes, such as strangulating obstructions of
the bowel or very serious obstructions.
Your vet will evaluate all these physical
parameters upon arrival. To further assist in arriving at a
diagnosis of what is causing the colic, he/she will perform a
rectal examination. This procedure entails a careful, systematic
palpation of bowel segments for position, tone, and contents of
each accessible loop of intestine. Gas-distended intestines
might point to a surgical condition, particularly if loops of
small intestine are abnormally distended. Displacement of
portions of the large colon can be felt. Presence or absence of
feces in the rectum is noted.
Manure, if present, is examined for
information. Are the fecal balls of normal size and consistency,
or are they firm or dry, indicating dehydration? Are the feces
coated with mucus, indicating delayed passage of the feces? Is
the manure soft or of a diarrhea consistency? An easy check for
sand in the manure can be done by placing six fecal balls in a
plastic glove and adding water. If more than one tablespoon of
sand settles out, that is significant, but if no sand is found
in that sample, that doesn't mean there isn't any. (Also, it is
common to see intermittent diarrhea or soft stools in horses
that chronically ingest sand.)
If gas-distended loops of intestine are
felt on rectal exam, if a displacement is obvious, or if an
impaction is found, a veterinarian can make a definitive
diagnosis. The original cause might remain elusive, but the
anatomical problem can be defined. Coupling the findings of a
rectal exam with cardiovascular parameters and lack or presence
of intestinal activity provides a veterinarian with concrete
information regarding the need for aggressive medical treatment
or surgery.
If a horse has colic, the veterinarian will
pass a nasogastric tube into the horse's stomach. Smooth muscles
lining the esophagus do not allow a horse to burp or vomit, so
large quantities of gas or fluid can accumulate within the
stomach, contributing to pain and cardiovascular compromise. A
stomach tube allows an avenue for escape of any painful gas and
fluid pressures in the stomach. This improves blood flow through
a distended bowel and to the heart.
Copious quantities of fluid (more than
0.5-3.0 gallons, or 2-12 liters) drained through a stomach tube
indicate stagnation or obstruction of the small intestine,
possibly (but not always) representative of a surgical
condition. Not only does a stomach tube provide valuable
diagnostic information, but it is also a means to administer
intestinal protectants, laxatives, fluids, and electrolytes.
Based on the evaluation of intestinal motility, your
veterinarian will decide if it is safe to administer something
via stomach tube. What to give is determined from specific
rectal exam findings and the thorough physical exam.
If a horse poses a questionable surgical
case, your veterinarian might obtain a sample of peritoneal
fluid by inserting a needle into the abdominal cavity (a
procedure called abdominocentesis). This is a relatively
painless procedure, with a horse only responding to the needle
prick as it passes through the skin. Examination of peritoneal
fluid is not always a reliable test for a decision for surgery,
but if the color is abnormal or the protein content of the
peritoneal fluid is higher than normal (indicating damaged
intestine or an infection in the abdomen), then surgery is most
likely indicated. Straw-colored peritoneal fluid is normal,
whereas pink or orange peritoneal fluid signifies devitalization
of an intestinal segment and the need for surgery or euthanasia.
In three-quarters of all colic cases, a
definite diagnosis is not achieved. Continual observation and
monitoring of a horse with an unspecified source of colic by
both owner and veterinarian is essential until the horse
responds to medical therapy, or a decision is made to go to
surgery.
Bowel Abnormalities Leading to Colic
Gaseous or spasmodic colic is similar to how you feel when you eat too rich a meal and
experience gas pain. Similarly, your horse might experience
gaseous colic from excess food fermentation. Copious amounts of
grain, or or abrupt changes to diets rich in alfalfa or other
legumes, predispose a horse to this kind of colic.
A simple obstruction develops from
foreign bodies, sand, enteroliths, packed food material, or
compression adjacent to the bowel from adhesions, tumors, or
abscesses. Pain is often mild or intermittent, but as a
mechanical obstruction persists, the buildup of gas and fluid in
the bowel increase distension, pressure, and pain. The lining of
the intestine begins to degenerate, allowing release of bacteria
and toxins into the bloodstream. If instituted early on, therapy
with pain-relieving medications and massive quantities of
intravenous fluids (5.3-10.6 gallons, or 20-40 liters) might
assist in softening and moving a feed or sand impaction on
through. However, if such a colic persists for more than eight
to 12 hours, or if a horse begins to deteriorate in
cardiovascular status, surgery might be indicated.
In a study by Nat White, DVM, Dipl. ACVS,
at the Marion duPont Scott Equine Medical Center in Virginia, an
interesting piece of information was discovered on the operating
table: Most cases of intestinal torsion or displacement appeared
to be precipitated or associated with an impaction in the right
dorsal colon (a section of the large intestine). It is
speculated that a large food mass might precipitate the descent
of the colon in the abdomen, whereupon it can twist on its axis
or tangle in a knot. An impaction occurs for many different
reasons, but one primary reason can be attributed to anything
that causes the intestines to shut down for an extended period
of time. This could be something as simple as rigorous exercise,
particularly when coupled with the inevitable dehydration that
accompanies travel and competitive events.
Sand colic can
develop as an irritant to the bowel lining or as a simple
obstruction. About 35% of horses with sand colic develop
diarrhea before the onset of painful signs. In some horses, the
only presenting signs might be depressed appetite and/or weight
loss. Performance might suffer because of chronic discomfort or
reduced nutrient efficiency. Other horses experience low-grade,
mildly painful bouts of colic that are intermittent, but
recurrent. Sometimes a colic crisis is precipitated during or
after riding, possibly because the sandpaper-like abrasion
stimulates painful spasms of the intestine.
Horses can ingest up to 2 1/2% of their
body weight each day. This can translate into up to 25 pounds of
roughage per day for a 1,000 pound horse. If the diet lacks
fiber, a horse will seek it out in the form of board fences,
weeds, or dirt. Also, a fiber deficiency limits normal
stimulation of the large colon, resulting in a more sluggish
intestinal motility that might allow sand to precipitate out
into the intestine. Feeding adequate amounts of roughage (such
as hay or grass), or feeding at frequent intervals, can decrease
aberrant behavior such as licking the ground or dirt eating,
called pica. The most effective means of limiting the
development of sand colic is to feed plenty of good-quality hay
to promote efficient intestinal activity. Avoid overstocking
pastures to keep ample forage available so horses are not forced
to consume dirt. Also, maintain clean, fresh water supplies to
encourage drinking, which in itself promotes gastrointestinal
health and normal motility.
A displacement refers to colic
associated with a loop or more of bowel that has moved out of
its normal position. Many intestinal displacements will rectify
themselves with medical treatment if bowel motility can be
restored with IV fluids. In some instances, no matter how
aggressive the therapy, the displaced bowel will become twisted
or entrapped, necessitating surgical intervention.
A strangulation obstruction usually
is accompanied by an acute and severe onset of pain. In these
cases, torsion or volvulus involves twisting of a loop of
bowel, which completely blocks off its blood supply. Another
possible type of strangulation obstruction occurs if a piece of
bowel is incarcerated (trapped) through an opening like a
diaphragmatic hernia, an umbilical or scrotal hernia, or through
a tear in the mesentery (the membranes that connect the
intestines and their appendages to the dorsal or upper wall of
the abdominal cavity).
An intestinal lipoma is a fatty
tumor on a stalk that can wrap around a loop of bowel, thus
strangulating it. The pelvic flexure (a portion of the large
colon on the left side) can become entrapped behind the ligament
of the spleen, which is known as a nephrosplenic entrapment.
If a loop of bowel telescopes inside itself--called an
intussusception--the blood supply is interrupted and that
area of the bowel begins to die.
In previous decades, post-mortem exams of
colic deaths revealed that 90% suffered from damage to
intestinal blood vessels due to migration of Strongylus
vulgaris larvae. Occlusion of blood vessels by larvae and
clots created by their presence resulted in a syndrome known as
a non-strangulation infarction (death of tissue due to a
local lack of oxygen). In these cases, blood supply to the bowel
is obstructed, although initially, the bowel itself was in
normal health. As blood flow ceases, intestinal motility is
disrupted to affected loops of bowel. The end result mimics a
strangulation obstruction due to accumulation of gas, fluid, and
toxins as bowel degenerates and shock develops. Due to a vast
education program and implementation of effective deworming
drugs at frequent intervals, parasites are a far less common
cause of fatal colic in horses today.
Gastric ulcer syndrome
can cause intestinal pain with the potential for
colic. Ulceration of the stomach or the right dorsal colon can
occur due to physical or behavioral stress, or due to long-term
administration of non-steroidal anti-inflammatory medications
like flunixin or phenylbutazone.
The Bottom Line
There are many types and causes of colic
pain in horses, ranging from mild belly aches to fatal damage.
Recognizing signs early and communicating the status and history
of your horse to your veterinarian will increase your chances of
catching the problem early enough for a successful outcome.
| NORMAL AND ABNORMAL VITAL SIGNS |
|
PARAMETER |
HOW TO EVALUATE |
NORMAL RANGE/ APPEARANCE
(horse at rest) |
VARIATIONS |
SIGNIFICANCE |
|
Mucous
membranes (gums, sclera of the eye, or a mare's vulvar
lips) |
Press a
fingertip to the membranes to blanch away the color
|
Refill
time should be no more than two seconds |
Pale membranes with slow refill time |
Inadequate cardiovascular circulation that might precede
development of shock |
|
Brick-red membranes with rapid refill time of less than
one second |
Shock. Horses in shock from colic require rapid
anti-shock therapy with drugs, intravenous fluids, and
surgery |
|
Blue or purple mucous membranes |
Severe, irreversible shock with a grave prognosis. The
horse will not likely survive anesthesia or surgery
|
|
Heart
rate |
Best
taken with a stethoscope on the left side of the horse's
chest, just behind the elbow. Each "lub dub" is
considered one beat. You also can take the pulse from
the lingual artery, on the bottom side of the jaw where
it crosses over the bone. Take the pulse for 15 seconds
and multiply by four to determine the heart rate in
beats per minute. The pulse should be bounding and
strong |
30-40
beats per minute |
40-60 beats per minute
|
Pain
|
|
Heart rate that persists between 60-80 beats per minute
for more than 15 minutes |
Severe dehydration or the beginning stages of shock |
|
Greater than 80 beats per minute in a colicky horse
|
Horse is in shock and is in desperate need of surgical
intervention or intensive care. Survival rate on these
types of cases is only about 25% |
|
Greater than 100 beats per minute in a colicky horse
|
Grave prognosis with a very low survival rate (less than
10%) |
|
Respiratory rate |
The respiratory rate (RR) can be taken by watching the
horse's chest move in and out (each inhale/exhale is one
breath) or feeling the air come out of his nostrils. A
stethoscope can be used. Breaths should sound clear |
12-24 breaths per minute depending on the ambient
temperature |
Rapid, shallow breathing |
Pain, fever or severe alterations in metabolic status of
the horse |
|
Rectal
temperature |
Shake
the thermometer down if using the glass/mercury kind,
and place a small amount of lubricant (petroleum jelly
or KY Jelly) on the thermometer before inserting into
the anus |
98-101.2°F |
Fever |
Endotoxemia, severe dehydration, or a septic condition
within the abdomen or thorax |
|
Low body temperature with cold and clammy limbs and a
cold muzzle |
Shock |
|
Intestinal sounds |
Use a
stethoscope to listen to both sides of the flank and on
the abdominal midline at the level of the girth near the
sternum |
At
least two rumbling/ gurgling/ tinkling sounds should be
heard each minute over each quadrant of both sides of
the flanks |
No sounds |
Abnormal gut motility requiring immediate treatment |
|
Sound similar to a pebble falling down a well
|
Gas in the bowel |
|
Squeaky noises |
An attempt at peristaltic (successive waves) GI movement
with no progressive move-ment of material though the
intestines |
|
Excessive amount of intestinal noise |
Spasms or hyperactivity due to irritation in the bowel,
or efforts to correct an obstruction |
|
Sound similar to a roiling surf on a sandy beach or sand
moving in a paper bag |
Sand colic |
AVOIDING THE ISSUE
Despite all of the advances in modern
veterinary medicine, colic is still the number one killer of
horses. In an attempt to provide our horses with the best, we
have inadvertently interfered with an efficient digestive
adaptation that developed over millennia. Horses are at their
digestive best when foraging on dried grasses scattered over
arid ground and roaming in search of sustenance. The horse
evolved to intermittently snack throughout the day, yet we place
him in confined spaces and twice daily supply him with abundant
food that is dried and in a relatively concentrated form. It is
a wonder that horses have as little colic as they do.
Unequivocally, it is agreed that the most
effective way to prevent colic is to minimize changes in your
management practices. Horses are creatures of habit; they thrive
on routine, both mentally and physically. The most appropriate
means of saving your horse from colic is for you to apply
excellent preventive management.
- Provide clean water always. Make sure
it remains unfrozen in winter.
- Keep your horse's diet consistent, and
feed at least 60% of his diet (by weight) as roughage (hay
or pasture). High-grain diets increase colic risk by three
to four times.
- Avoid changes in feed when possible.
There is a quadruple increase in colic risk when diet is
changed.
- Feed good-quality hay, not too coarse
and not too fine. Avoid dust and mold.
- Use feeding systems that minimize
eating directly off the ground. The best technique is a
feeding system that prevents your horse from spreading hay
through the dirt.
- Feed psyllium products for five to
seven consecutive days each month to move dirt and sand
through the bowel if sand colic is a problem in your area.
- Implement an aggressive deworming
program with regular fecal examinations and dosing with a
deworming medication every four to eight weeks as indicated
by the fecal examination. Dose appropriately to your horse's
body weight and make sure all of the medication is ingested.
- Pick up manure in paddocks at least
twice a week to minimize load of infective parasitic larvae.
- Have yearly dental exams and teeth
filing performed by your veterinarian to enable your horse
to adequately grind his feed.
- Allow your horse ample exercise,
either with turn-out or under saddle.
By recognizing an evolutionary need for
horses to frequently eat small amounts of good-quality fiber,
feeding practices can be modified to promote improved health of
the digestive system and improved mental happiness. A horse
performs better in all ways if his natural urge to constantly
nibble is satisfied. This is accomplished by providing
free-choice grass hay, and only supplementing hard-working
individuals or difficult keepers with alfalfa, corn oil, and
limited grain. A salt block and adequate water should be
available at all times. This uncomplicated diet minimizes sand
ingestion, the risk of laminitis, obesity-related strangulating
lipomas (fatty tumors), and colic that results from feeding
richer foodstuffs.
WHY IS RAPID INTERVENTION
IMPORTANT?
A horse's intestinal tract spans 70-90 feet
in length, with abrupt changes in its diameter and direction.
With interruption of normal waves of contraction (peristalsis)
in the bowel, excessive gas or fluid can accumulate in the gut.
As feed fermentation continues, gas must be able to move toward
the rectum or it will build within the intestines, with pain
resulting from over-distension. Gas in the intestines, or the
added weight of fluid, along with abnormal peristaltic
contractions, brings on a displacement in the positioning of
loops of bowel.
Bacterial overgrowth develops with
stagnation from obstructions or displacements. Eventually,
bacteria begin to die, releasing endotoxins (poisonous
components of the cell wall of Gram-negative bacteria) that
contribute to dehydration, shock, laminitis, and potential
death.
A main objective in medical therapy is to
restore normal motility to the intestines, not only to move gas,
fluid, and food through the tract, but also to prevent
sequestration of vital body fluids within a stagnant bowel. If
intestinal fluids are not absorbed into the circulatory system,
a horse progressively dehydrates and suffers serious fluid and
electrolyte imbalances. Blood supply is further compromised due
to mounting pressures and tension on blood vessels throughout
the abdominal cavity. Over time, with diminished circulating
blood volume through the body, hypo-volemic (diminished fluid
volume) shock compounds the crisis.
When addressed rapidly and effectively,
many cases of colic are resolved with appropriate medical
treatment. Rather than an owner administering analgesic
(pain-killing) drugs and waiting to see if a horse responds, a
veterinarian should be summoned. While awaiting the
veterinarian's arrival, vital signs can be recorded by the owner
to be used for comparison to a veterinarian's findings. (These
include heart rate, respiratory rate, rectal temperature, and
color and refill time of the mucous membranes.)
If you are tempted to give your horse drugs
before your veterinarian arrives, consider that sedatives or
non-steroidal anti-inflammatory drugs often mask pertinent
information about your horse's status. This could delay a
decision for aggressive medical treatment or to send a horse to
surgery. These drugs should only be administered by a
veterinarian after a thorough examination or on your
veterinarian's orders. Delays in surgical intervention are
believed to be the most common cause of surgical failure.
