1. TItle: Horse Colic database

2. Source Information
   -- Creators: Mary McLeish & Matt Cecile
	  	Department of Computer Science
		University of Guelph
		Guelph, Ontario, Canada N1G 2W1
		mdmcleish@water.waterloo.edu
   -- Donor:    Will Taylor (taylor@pluto.arc.nasa.gov)
   -- Date:     8/6/89

3. Past Usage:
   -- Unknown

4. Relevant Information:

   -- 2 data files
      -- horse-colic.data: 300 training instances
      -- horse-colic.test: 68 test instances
   -- Possible class attributes: 24 (whether lesion is surgical)
     -- others include: 23, 25, 26, and 27
   -- Many Data types: (continuous, discrete, and nominal)

5. Number of Instances: 368 (300 for training, 68 for testing)

6. Number of attributes: 28

7. Attribute Information:

  1:  surgery?
          1 = Yes, it had surgery
          2 = It was treated without surgery

  2:  Age
          1 = Adult horse
          2 = Young (< 6 months)

  3:  Hospital Number
          - numeric id
          - the case number assigned to the horse
            (may not be unique if the horse is treated > 1 time)

  4:  rectal temperature
          - linear
          - in degrees celsius.
          - An elevated temp may occur due to infection.
          - temperature may be reduced when the animal is in late shock
          - normal temp is 37.8
          - this parameter will usually change as the problem progresses
               eg. may start out normal, then become elevated because of
                   the lesion, passing back through the normal range as the
                   horse goes into shock
  5:  pulse
          - linear
          - the heart rate in beats per minute
          - is a reflection of the heart condition: 30 -40 is normal for adults
          - rare to have a lower than normal rate although athletic horses
            may have a rate of 20-25
          - animals with painful lesions or suffering from circulatory shock
            may have an elevated heart rate

  6:  respiratory rate
          - linear
          - normal rate is 8 to 10
          - usefulness is doubtful due to the great fluctuations

  7:  temperature of extremities
          - a subjective indication of peripheral circulation
          - possible values:
               1 = Normal
               2 = Warm
               3 = Cool
               4 = Cold
          - cool to cold extremities indicate possible shock
          - hot extremities should correlate with an elevated rectal temp.

  8:  peripheral pulse
          - subjective
          - possible values are:
               1 = normal
               2 = increased
               3 = reduced
               4 = absent
          - normal or increased p.p. are indicative of adequate circulation
            while reduced or absent indicate poor perfusion

  9:  mucous membranes
          - a subjective measurement of colour
          - possible values are:
               1 = normal pink
               2 = bright pink
               3 = pale pink
               4 = pale cyanotic
               5 = bright red / injected
               6 = dark cyanotic
          - 1 and 2 probably indicate a normal or slightly increased
            circulation
          - 3 may occur in early shock
          - 4 and 6 are indicative of serious circulatory compromise
          - 5 is more indicative of a septicemia

 10: capillary refill time
          - a clinical judgement. The longer the refill, the poorer the
            circulation
          - possible values
               1 = < 3 seconds
               2 = >= 3 seconds

 11: pain - a subjective judgement of the horse's pain level
          - possible values:
               1 = alert, no pain
               2 = depressed
               3 = intermittent mild pain
               4 = intermittent severe pain
               5 = continuous severe pain
          - should NOT be treated as a ordered or discrete variable!
          - In general, the more painful, the more likely it is to require
            surgery
          - prior treatment of pain may mask the pain level to some extent

 12: peristalsis
          - an indication of the activity in the horse's gut. As the gut
            becomes more distended or the horse becomes more toxic, the
            activity decreases
          - possible values:
               1 = hypermotile
               2 = normal
               3 = hypomotile
               4 = absent

 13: abdominal distension
          - An IMPORTANT parameter.
          - possible values
               1 = none
               2 = slight
               3 = moderate
               4 = severe
          - an animal with abdominal distension is likely to be painful and
            have reduced gut motility.
          - a horse with severe abdominal distension is likely to require
            surgery just tio relieve the pressure

 14: nasogastric tube
          - this refers to any gas coming out of the tube
          - possible values:
               1 = none
               2 = slight
               3 = significant
          - a large gas cap in the stomach is likely to give the horse
            discomfort

 15: nasogastric reflux
          - possible values
               1 = none
               2 = > 1 liter
               3 = < 1 liter
          - the greater amount of reflux, the more likelihood that there is
            some serious obstruction to the fluid passage from the rest of
            the intestine

 16: nasogastric reflux PH
          - linear
          - scale is from 0 to 14 with 7 being neutral
          - normal values are in the 3 to 4 range

 17: rectal examination - feces
          - possible values
               1 = normal
               2 = increased
               3 = decreased
               4 = absent
          - absent feces probably indicates an obstruction

 18: abdomen
          - possible values
               1 = normal
               2 = other
               3 = firm feces in the large intestine
               4 = distended small intestine
               5 = distended large intestine
          - 3 is probably an obstruction caused by a mechanical impaction
            and is normally treated medically
          - 4 and 5 indicate a surgical lesion

 19: packed cell volume
          - linear
          - the # of red cells by volume in the blood
          - normal range is 30 to 50. The level rises as the circulation
            becomes compromised or as the animal becomes dehydrated.

 20: total protein
          - linear
          - normal values lie in the 6-7.5 (gms/dL) range
          - the higher the value the greater the dehydration

 21: abdominocentesis appearance
          - a needle is put in the horse's abdomen and fluid is obtained from
            the abdominal cavity
          - possible values:
               1 = clear
               2 = cloudy
               3 = serosanguinous
          - normal fluid is clear while cloudy or serosanguinous indicates
            a compromised gut

 22: abdomcentesis total protein
          - linear
          - the higher the level of protein the more likely it is to have a
            compromised gut. Values are in gms/dL

 23: outcome
          - what eventually happened to the horse?
          - possible values:
               1 = lived
               2 = died
               3 = was euthanized

 24: surgical lesion?
          - retrospectively, was the problem (lesion) surgical?
          - all cases are either operated upon or autopsied so that
            this value and the lesion type are always known
          - possible values:
               1 = Yes
               2 = No

 25, 26, 27: type of lesion
          - first number is site of lesion
               1 = gastric
               2 = sm intestine
               3 = lg colon
               4 = lg colon and cecum
               5 = cecum
               6 = transverse colon
               7 = retum/descending colon
               8 = uterus
               9 = bladder
               11 = all intestinal sites
               00 = none
          - second number is type
               1 = simple
               2 = strangulation
               3 = inflammation
               4 = other
          - third number is subtype
               1 = mechanical
               2 = paralytic
               0 = n/a
          - fourth number is specific code
               1 = obturation
               2 = intrinsic
               3 = extrinsic
               4 = adynamic
               5 = volvulus/torsion
               6 = intussuption
               7 = thromboembolic
               8 = hernia
               9 = lipoma/slenic incarceration
               10 = displacement
               0 = n/a
 28: cp_data
          - is pathology data present for this case?
               1 = Yes
               2 = No
          - this variable is of no significance since pathology data
            is not included or collected for these cases

8. Missing values: 30% of the values are missing