Equine gastrointestinal tract

Question 1

Describe the GI tract of a horse.

Answer 1

hindgut fermenter, herbivore, i.e. most microbial activities take place in the cecum & large intestine which constitutes approximately 60 per cent of the gastro-intestinal tract

Question 1

Chronic diarrhea in horses is defined as a

Answer 1

diarrhea that has lasted several days with no improvement.

Question 2

in the adult horse chronic diarrhea is the result of

Answer 2

large intestinal diseases

Question 3

What is the FLASH technique?

Answer 3

FLASH scanning technique for colic patients, stands for Fast Localised Abdominal Sonography of Horses and can be used
to aid decision making in horses with colic, and may be more accurate for detecting lesions requiring surgical intervention versus per-rectum palpation.

Question 4

a quick, noninvasive tool for formulating accurate diagnosis of horses
presenting with acute colic

Answer 4

transcutaneous ultrasound

Question 5

equine main energy source (not food):

Answer 5

volatile fatty acids (VFA-s) produced by bacterial fermentation in the large intestine

Question 6

What is equine FUO?

Answer 6

Fever of unknown origin (FUO) is a syndrome characterized by prolonged, unexplained fever associated with non-specific signs of illness such as lethargy, inappetence and weight loss.

Question 7

Feeding large quantities of concentrates is a risk factor for

Answer 7

gastric ulcers/colic

Question 8

Decreased water consumption or decreased
movement (sudden box rest) is a risk factor
for

Answer 8

impaction colic

Question 9

Increased risk for enteroliths if horse fed

Answer 9

alfalfa

Question 10

Recent foaling is a risk factor for what GI problem?

Answer 10

colonic torsion

Question 11

Crib-biting and windsucking increase the
risk of

Answer 11

colic

Question 12

How to assess horse’s cardiovascular status (4)

Answer 12

mm-s color and moisture, CRT, jugular filling

Tachycardia should always raise
a concern.

Mms:
– Normally (pale) pink, moist, crt <2 sec
– Darker pink to purple in toxic horses
– Dry or tacky in dehydrated horse

Question 13

Pain helps to differentiate between

Answer 13

surgical and medical lesions with some exceptions

Question 14

Describe auscultation of Ileocecocolic sounds

Answer 14

Ileocecocolic sound in right paralumbar area
– 1-3 times/min
– Sound resembles flushing a toilet

Lack of gut sounds indicates a marked abnormality.

Question 15

What part of the GI tract can be auscultated in the Left paralumbar area:

Answer 15

pelvic flexure, ascending colon

Lack of gut sounds indicates a marked abnormality.

Question 16

Abdominal distention Often indicates
distention of the

Answer 16

large intestine.

Sometimes large portion of small intestine is involved.

Question 17

What is OGAT?

Answer 17

The oral glucose tolerance test in the horse provides an aid to the diagnosis of pancreatic and small intestinal dysfunction/malabsorption syndromes.

A dose of 1 g. glucose/Kg bodyweight is administered by stomach tube producing a peak glucose level after two hours, which returns to the resting level four hours later.

This test has no relevance to large intestinal disease such as parasitism.

Question 18

Nasogastric intubation: purpose (4)

Answer 18

1. To evacuate fluid or gas from the stomach.
2. Administration of enteral fluids/medications/supplements.
3. To relieve esophageal obstruction.
4. Diagnostic value– Large quantities of
   reflux indicate a SI lesion (usually).

Question 19

Restraint for NG intubation requires

Answer 19

(twitch +/- sedation) and an assistant

Question 20

presence of reflux: what amount of fluid out of a large horse is abnormal

Answer 20

more than 2 liters of fluid out of a large horse
is abnormal

– In that case do not put ANYTHING in the
stomach.

Question 21

What does abnormal reflux tell you?

Answer 21

Usually indicates a SI problem (or a long lasting/severe LI problem).

■ Indicates that Fluid cannot pass from the stomach into the small intestine.

■ There could be Closure of the intestinal lumen (displacement, torsion, mass).

■ Inflammation (large amount of fluid produced
by intestinal mucosa).
‘
■ Appearance and smell of fluid: the smellier,
darker, redder, the more likely there’s an
inflammation or serious intestinal damage.

Question 22

NG intubation: complication epistaxis is usually due to

Answer 22

ethmoidal trauma

– Happens occasionally
– Usually of low significance and stops spontaneously.

– To prevent: always use proper restraint, guide the tube ventromedially and advance the tube gently; at removal maintain downward angle and avoid sudden movements.

Question 23

Rectal examination: purpose

Answer 23

Used to evaluate horse with acute or chronic colic and/or weight loss.

Allows evaluation of structures in the caudal part of abdomen.

Question 24

Rectal examination: safety

Answer 24

Risk of rectal tears
■ Can be irreparable depending on the grade
■ Always check rectal glove after the examination for traces of blood.

– Use of parasympatholytics (Buscopan) helps to relax intestines.

Question 25

Abdominocentesis: purpose

Answer 25

If you suspect:
■ Peritonitis
– WBC
– TP

■ Abdominal hemorrhage
■ Intestinal rupture
■ Neoplastic process in abdominal cavity

– To assess viability of the intestinal wall (ischemic damage).
■ Lactate

Colic, chronic diarrhea, weight loss, FUO etc.

Question 26

Abdominocentesis should be ultrasound guided when?

Answer 26

in foals and pregnant mares

Question 27

Abdominocentesis: correct sample tubes

Answer 27

■ EDTA-tube (purple) for cytology

■ Plain tube (white) for culture

■ Li-heparin tube (green) for lactate

Question 28

Appearance of Normal abdominal fluid

Answer 28

Pale yellow, transparent

Question 29

Abdominocentesis: complications (4)

Answer 29

■ Enterocentesis
■ Splenic aspiration
■ Omental herniation (foals)
■ Cellulitis or abscess formation

Question 30

Abdominal ultrasound: purpose

Answer 30

■ To evaluate abdominal organs

– Presence of free fluid in the abdomen
– Gut wall thickness
– Intestinal motility
– Appearance of spleen,
liver, kidneys
– In foals: umbilical blood
vessels, bladder

E.g. in the cases of Acute or chronic colic, weight loss, diarrhea

Question 31

FLASH =

Answer 31

fast localized abdominal sonography of horses

Question 32

FLASH: Purpose

Answer 32

To identify lesions that need surgery or a specific medical
therapy.

■ Should take about 10-15 min
■ Ideally without clipping
■ Especially useful in an emergency case
■ Does not need extensive experience

Question 33

FLASH: 7 windows

Answer 33

7 windows to obtain basic information for decisions :

1) ventral abdomen
2) gastric
3) spleno-renal
4) left middle third of the abdomen
5) duodenal
6) right middle third of the abdomen
7) cranioventral thoracic (right side)

Question 34

FLASH: left side

Answer 34

Question 35

FLASH: right side

Answer 35

Question 36

Describe Abdominal radiography in horses

Answer 36

■ Does not penetrate enough to be informative in large horses
■ Exception: sand in large intestine (or enteroliths)
■ More useful in foals

Question 37

3 most common Inflammatory markers in horses

Answer 37

WBC, fibrinogen, SAA

but there are more

Question 38

Lactate biochemistry can tell you about

Answer 38

problems with perfusion or ischemia

Question 39

TP/PCV is a cheap and effective aid to assess what

Answer 39

hydration.

Also a Good indicator of peripheral perfusion if combined with lactate.

Question 40

A PCV of 45-50% with a TP of 75-80 g/L in a horse indicates

Answer 40

mild dehydration

Question 41

A PCV of 50-60% with a TP of 80-90 g/L in a horse indicates

Answer 41

moderate dehydration

Question 42

A PCV of 60% with a TP of 90 g/L in a horse indicates

Answer 42

severe dehydration

Question 43

Fecal sampling purpose

Answer 43

To identify species and burden of internal
parasites.

To find a causative agent for diarrhea.

Question 44

Gastroscopy: procedure
Endoscope passed to the stomach via?

Answer 44

ventral nasal passage and esophagus

Question 45

Oral examination: when to perform?

Answer 45

■ As a routine: dental examination at least once a year

■ More often if older horse or known problems

Or if problems such as dysphagia, weight loss, recurrent colic etc.

Question 46

Number of teeth in adult horse.

Answer 46

36 not counting potential wolf and canine teeth

In addition to the incisors, premolars and molars, some, but not all, horses may also have canine teeth and wolf teeth.

The small one more rostrally is the canine and more caudal small one, wolf.