Sgu Svm Equine Internal Medicine Part 1

Front 1

Water makes up what portion of a patient's body weight?

Back 1

60%

Front 2

What 2 major compartments is water distributed within?

Back 2

ECF, ICF

Front 3

The ECF is divided into what 3 compartments?

Back 3

-intravascular
-interstitial
-tanscellular

Front 4

The blood volume of most mammals comprises how much of total body water?

Back 4

8%

Front 5

What is plasma?

Back 5

The non-cellular component of blood..communicates continuously with the interstitial fluid through a series of pores in the capillary cell membranes

Front 6

Are proteins more highly concentrated in the ECF of the plasma?

Back 6

Plasma

Front 7

Plasma proteins are negatively charged and attract what?

Back 7

Positively charged cations (NA, K)

Front 8

What is the result of the attraction of NA and K?

Back 8

Pulls water and lymph fluid from the interstitium into the vascular space

Front 9

Plasma proteins are responsible for creating what pressure?

Back 9

colloid oncotic

Front 10

What are the forces that govern fluid movement across endothelial membranes?

Back 10

Starling's forces (hydrostatic and oncotic)

Front 11

What is the primary ECF osmole?

Back 11

cation Na+

Front 12

What is the primary ICF osmole?

Back 12

cation K+

Front 13

Which space bears the brunt of the effects of pure water loss?

Back 13

ICF

Front 14

What are the normal water requirements of a 500kg horse?

Back 14

50ml/kg/day (6 gallons)

Front 15

When doe most water intake occur in the horse?

Back 15

Periprandial drinking

Front 16

What are the electrolyte balances in horse fed a diet high in hay?

Back 16

high K+
low Na+

Front 17

Horses receiving IV fluids for more than one day are at risk for low levels of which electrolyte?

Back 17

K+

Front 18

Low K+ can lead to what clinical sign?

Back 18

Muscle weakness

Front 19

Unlike other species, horses absorb excessive amounts of Ca from feed, how is the excess Ca eliminated?

Back 19

In the form of calcium crystals in the urine

Front 20

What is the cause of the turbid appearance of horse urine?

Back 20

calcium carbonate crystals and mucus

Front 21

What condition is the hallmark of dehydration?

Back 21

Hypernatremia

Front 22

What effect does pure water loss have on the tonicity of the ECF?

Back 22

increases it

Front 23

What effect does the increased tonicity of the ECF have on the ICF?

Back 23

Fluid redistributes from the ICF to the ECF

Front 24

How does the body correct for the elevation of Na+ resulting from dehydration?

Back 24

Osmoreceptors trigger thirst

Front 25

What is meant by the term hypovolemia?

Back 25

Loss of water and electrolytes

Front 26

If fluid lost from the ECF is isotonic, what effect will this have on the ICF?

Back 26

None, no change in water balance

Front 27

What are the cause of the loss of isotonic body fluid in the horse?

Back 27

-hemorrhage
-diarrhea
-vomiting
-sweating

Front 28

Fluid deficits that affect the ECF (isotonic deficits) cause a compromise of which body system?

Back 28

Circulatory

Front 29

A patient with hypovolemia suffers from a decrease of volume in which compartment?

Back 29

ECF

Front 30

What are the events that occur as a result of hypovolemia?

Back 30

-decreased return of venous blood to the heart
-decreased cardiac output
-activation of homeostatic mechanisms

Front 31

Decreased effective circulating volume leads to the activation of what system?

Back 31

Renin-Angiotensin-Aldoseterone System (RAAS)

Front 32

Renin is released from where?

Back 32

Juxtaglomerular cells of the afferent arteriole of the kidney

Front 33

What is the effect of renin?

Back 33

Causes converion of angiotensin I to angioternsin II (in the lungs)

Front 34

What other chemical is needed for this conversion?

Back 34

Angiotensin-converting enzyme (ACE)

Front 35

What is the effect of angiotensin II?

Back 35

AT II is a powerful vasoconstrictor...increase systemic blood pressure

Front 36

ATII stimulates the release of aldosterone from where?

Back 36

Adrenal cortex

Front 37

What is the effect of aldosterone?

Back 37

Enhances resorption of NA and CL, increasing vascular fluid volumes

Front 38

What effect do baroreceptors have on decreased volume?

Back 38

Stimulate sympathetic neurons in the CNS vis the vagus nerve, which increases heart rate and sympthetic vasoconstriction, improving CO and tissue perfusion

Front 39

What is the purpose of the body's osomoreceptor's?

Back 39

Monitor the tonicity of blood osmolalitiy

Front 40

Changes in blood osmolality causes the release of what? From where?

Back 40

Arginine Vasopressin AVP from the posterior pituitary

Front 41

AVP is also know as what?

Back 41

Anti diuretic hormone

Front 42

What effect does AVP have on the collecting duct of the kidney?

Back 42

Increases water resorption by placement of apical aquaporin channels (improves vasuclar volume and perfusion of tissues)

Front 43

AVP can also effect the release of what hormone?

Back 43

ACTH to release cortisol

Front 44

Are the homeostatic mechanisms long lived or short lived?

Back 44

Short lived

Front 45

What is dysoxia?

Back 45

The condition in which metabolic energy production is limited by the supply or utilization of oxygen

Front 46

What is the term for the clinical expression of dysoxia?

Back 46

Shock

Front 47

The adequacy of tissue oxygenation is determined by the balance of what 2 values?

Back 47

-oxygen delivered to the tissues (DO2)

-oxygen required to sustain aerobic metabolism (VO2) (rate of uptake of O2 into the tissues)

Front 48

When VO2 is sufficient, how many ATP are produced per mole of glucose?

Back 48

36

Front 49

When VO2 is not sufficient, some glucose is is diverted into the anaerobic production of what?

Back 49

lactate

Front 50

How many ATP are produced per mole of lactate?

Back 50

2

Front 51

What correlation has been shown, in humans, between lactate and survival?

Back 51

As blood lactate increases, survival decreases

Front 52

What determines the severity of hypovolemic shock?

Back 52

-rate and amount of fluid lost
-age of patient
-pre-existing disease

Front 53

Complications of decreased oxygen delivery to tissues include what conditions?

Back 53

-decreased coronary and cerebral perfusion
-systemic metabolic derangements (including anaerobic metabolism)

Front 54

Hypovolemic shock may be secondary to hemorrhage, V/D, fluid loss into the 3rd space...these fluid loses come primarily from which fluid compartment?

Back 54

ECF (vascular space)

Front 55

What are the clinical signs of dehydration?

Back 55

-tachycardia
-tacky mucus membranes
-prolonged skin tent
-sunken eyes
-increased USG
-irritable behavior (humans)
-muscle cramping (humans)

Front 56

What are the clinical signs of hypovolemia?

Back 56

-tachycardia
-decreased pulse pressure
-reduced jugular fill
-tachypnea
-cold extremities
-decreased urine output

Front 57

When do clinical signs of dehydration become evident?

Back 57

At ~5% dehydration

Front 58

What does 5% dehydrated mean?

Back 58

Decrement in body mass due to fluid loss

Front 59

Patients presenting with signs of hypovolemia may be ataxic, which may be confused with what condition?

Back 59

Neurologic clinical signs

Front 60

Dehydration and hypovolemia require immediate fluid therapy. What is the ideal measurement for assessing hydration?

Back 60

Body mass

Front 61

What are the 2 common lab parameters used for assessing hydration?

Back 61

PCV, TA

Front 62

Why is PCV not an accurate indicator of hydration in a horse?

Back 62

PCV can be raised due to excitement and splenic contraction

Front 63

Does plasma total protein increase with dehydration or with hypovolemia?

Back 63

Increases with both

Front 64

Horses with colitis will lose plasma protein from the GI tract. They present with increased PCV but normal to low protein. What typ eof fluids should they be given?

Back 64

Colloids- when giving fluids a horse with colitis with drop in PCV and TS, colloids will help avoid a hypoproteinemic state.

Front 65

Will a dehydrated horse have an increased or decreased USG?

Back 65

Increased
1.025-1.040

Front 66

What would you expect as a serum creatinine level in a hypovolemic horse?

Back 66

Increased (in the absence of renal dysfunction)

Front 67

Why would a dehydrated horse show a pre-renal azotemia?

Back 67

Temporary renal insufficiency related to decreased GFR due to hypovolemia

Front 68

What would you suspect if a patient has azotemia, but is isosthenuric?

Back 68

Renal failure

Front 69

Does measurement of lactate assist in determining dehydration or hypovolemia?

Back 69

Hypovolemia- decreased DO2 leads to anaerobic metabolism- glucose converted to lactate

Front 70

In vet med what should a normal L-lactate level be?

Back 70

<1.0 mmol/L

Front 71

The fraction of oxygen delivered to the capillaries that is actually taken up by the tissues is called what?

Back 71

The oxygen extraction ratio

The ration of oxygen uptake to oxygen delivery (VO2/DO2)

Front 72

What should the normal oxygen extraction ratio be?

Back 72

<25%

Front 73

What would you suspect is the oxygen extraction ratio increases?

Back 73

Dysoxia, or shock, is pending

Front 74

What measurement is used to estimate the oxygen extraction ratio?

Back 74

Central venous oxygen saturation (SvO2)

Front 75

In a normal patient, Sv02 should be what?

Back 75

> or = to 70%

Front 76

In patients with shock, the oxygen extraction rises to 50%- 60%...what SvO2 will you see?

Back 76

< 70%

Front 77

What measurement is used to evaluate effective circulating volume?

Back 77

Central venous pressure (CVP)

Front 78

Central venous pressure is a measurement of what?

Back 78

Right atrial pressure (pre-load)

Front 79

In horses, what is a normal range for CVP?

Back 79

5-14mm Hg

Front 80

What does an elevated CVP indicate?

Back 80

Fluid overload

Front 81

What is the goal of fluid therapy in the hypovolemic patient?

Back 81

Incease intravascular volume to improve venous return and cardiac output within 1-2 hours

Front 82

A shock dose of fluids is considered to be what volume?

Back 82

One blood volume, 8% of total body weight

Front 83

In the horse, what is the rate for delivering a shock dose of fluids?

Back 83

Administer 1/4 of the dose as a bolus, reasses, if signs persist continue until 1 blood volume is given

Front 84

Correction of dehydration requires that fluids be given over what time period?

Back 84

12-24 hours

Front 85

What does the term crystalloid mean?

Back 85

A substance in a solution that can diffuse through a semi-permeable membrane

Front 86

What are the primary electrolytes in crystalloid fluids?

Back 86

Na+ and Cl-

Front 87

Crystalloids are designed to replace fluid in which compartment?

Back 87

In the interstitium (leak from the vascular space)

Front 88

What volume of administered crystalloids will remain in the vascular space 30 minutes after administration?

Back 88

1/4 of the volume administered

Front 89

Crystalloids are an excellent source for electrolyte replacement but can also be a cause of what?

Back 89

Edema formation with fluid overload

Front 90

What is tonicity?

Back 90

The osmotic pressure of a solution based on the number of particles per kilogram of solution (osmolality)

Front 91

What effect can a hypotonic solution have on RBC's?

Back 91

Can cause them to swell and rupture

Front 92

What effect can a hypertonic solution have on RBC's?

Back 92

Can cause them to shrink (crenation)

Front 93

What is the tonicity of plasma?

Back 93

280 mOsm/L

Front 94

What effect do isotonic fluids have when administered?

Back 94

Temporary increase in plasma volume without causing electrolyte disturbances of fluid shift from the ICF

Front 95

Which isotonic crystalloid is ideal for a hyperkalemic patient?

Back 95

Normal saline (.9% NaCl)
isotonic but has greater amounts of Na and Cl

do not use for resusciation due to potential development of hyperchloremic metabolic acidosis

Front 96

What is an example of a hypotonic solution?

Back 96

0.45% NaCl (half-strength saline)

Front 97

Why should half-strength saline be used with caution?

Back 97

Is half the tonicity of plasma, can cause cells to swell

Front 98

In patients with chronic hyponatremia, cells produce what to pull water into the cell?

Back 98

idiogenic osmoles

Front 99

Why is hypotonic saline given to these patients?

Back 99

They must have Na+ replaced slowly with a solution that resembles the abnormal plasma tonicity to prevent cell swelling

Front 100

Which solution provides no additional electrolytes?

Back 100

Water (D5W)

Front 101

Is D5W a good choice for resuscitation of hypovolemia?

Back 101

No- less than 10% remains in the vascular space after 30 minutes, a bolus can cause severe hyperglycemia

Front 102

What is an example of a hypertonic fluid?

Back 102

7% NaCl, hypertonic saline

Front 103

Hypertoninc saline quickly increases the tonicity of the ECF and interstitium. What effect does it have on the ICF?

Back 103

Draws water from the interstitium and ICF into the vascular space

Front 104

What is the general rule of thumb for giving additional fluids when hypertonic saline is used?

Back 104

For every liter of hypertonic, 10 liters of isotonic should be given as replacement to the ICF

Front 105

What are colloids?

Back 105

Large branched molecules which exert substantial colloidal oncotic pressure and may act as capillary pore plugs preventing fluid from leaking from the vasculature

Front 106

What are 2 commonly used colloids used in equine medicine?

Back 106

-fresh frozen equine plasma
-hetastarch

Front 107

Why are colloids a good fluid choice for endotoxemia and ischemia-reperfusion injury?

Back 107

Both conditions cxause capillary damage which allow plasma proteins to leak into the interstitium..proteins in the insterstitium draw water from the vascular space causing edema

Front 108

What is a drawback to using hetastarch at high doses? (>20 ml/kg

Back 108

Prolonged bleeding times

Front 109

What is the drawback to measuring TS when using hetastarch?!

Back 109

Doesn't measure on a refractometer

Front 110

What are the benefits of using equine fresh frozen plasma in colitis patients?

Back 110

-offers albumin
-clotting factors
-anti-endotoxemic factors

Front 111

How is plasma administered to decrease the potential for a reaction?

Back 111

Adminsiter slowly over the first 20 minutes, monitoring TPR and for signs of urticaria

Front 112

What methods can be used to encourage a horse to increase their oral intake of fluids?

Back 112

-electrolyte pastes
-salt slurries

Front 113

True or False. The SQ route of fluid administration for horses works well.

Back 113

False

Front 114

Which method of fluid administration is used to give large volumes of fluids easily?

Back 114

Enteral (NG tube)

Front 115

How much fluid can be safely given via NG tube?

Back 115

4-6 L per dose repeated every 1-2 hours

Front 116

What must be checked before administering any GI fluids to a horse?

Back 116

Check for gastric reflux

Front 117

What methods can be used to encourage a horse to increase their oral intake of fluids?

Back 117

-electrolyte pastes
-salt slurries

Front 118

True or False. The SQ route of fluid administration for horses works well.

Back 118

False

Front 119

Which method of fluid administration is used to give large volumes of fluids easily?

Back 119

Enteral (NG tube)

Front 120

How much fluid can be safely given via NG tube?

Back 120

4-6 L per dose repeated every 1-2 hours

Front 121

What must be checked before administering any GI fluids to a horse?

Back 121

Check for gastric reflux

Front 122

True or False. The enteral route is not an adequate route for resuscitating a hypovolemic horse.

Back 122

True- use the IV route

Front 123

IV fluid administration in a horse usually requires the placement of catheters where?

Back 123

Jugular veins

Front 124

Physiologic processes of the body are optimized at what pH?

Back 124

7.4

Front 125

The hydrogen ion content of the ECF is determined by what?

Back 125

The balance between the partial pressure of CO2 (PCO2) and the concentration of bicarb (HCO3-)

Front 126

When a primary acid-base disturbance alters 1 component of the PCO2/HCO3 ratio, what direction does the compensatory mechanism move?

Back 126

Same direction, to keep the ratio constant

Front 127

What are the 2 reasons to perform a blood gas analysis?

Back 127

-determine acid/base status
-evaluate respiratory gas exchange

Front 128

Which blood gas type is used for determining acid/base status?

Back 128

Venous blood gas

Front 129

Why is an arterial blood gas used to determine blood gas-oxygen exchange?

Back 129

Arterial blood hasn't traveled through the systemic capillary network and subsequent exposure to cell uptake and waste

Front 130

What anticoagulant is used in ABG collection?

Back 130

Dry lithium heparin

Front 131

What is the term for a disturbance that alters the amount of CO2 in the blood?

Back 131

Respiratory acid-base alteration

Front 132

As CO2 increases, what happens to pH?

Back 132

It decreases

Front 133

Aside from the lungs, what other body organs affect acid-base balance?

Back 133

GIT & kidney

Front 134

How quickly does the respiratory system compensate for acid-base alterations?

Back 134

Minute by minute

Front 135

What is the first step in evaluating a potential acid-base alteration?

Back 135

determine the pH (acidosis/alkalosis)

Front 136

What component on a blood gas report reflects the respiratory component of an altered acid-base balance?

Back 136

PCO2

Front 137

The normal respiratory components of a blood gas report include what?

Back 137

HCO3 and base excess

Front 138

Is PCO2 increased or decreased with a respiratory acidosis?

Back 138

Increased

Front 139

A metabolic acidosis is can be caused by what 2 conditions?

Back 139

-gain of H+
-loss of HCO3

Front 140

What conditions can cause a gain of H+?

Back 140

-increased H+ production (ketoacidosis, lactic acidosis)
-metabolism of ingested toxins (ethylene glycol)
-decreased reanl excretion of H+ (renal tubular acidosis)

Front 141

Loss of HCO3 is usually attributed to what?

Back 141

Vomiting/diarrhea
loss from kidney

Front 142

Why is knowing the etiology of an acidosis important?

Back 142

Determine is supplemental bicard is indicated

Front 143

An increased in plasma HCO3- is termed what?

Back 143

Metabolic alkalosis

Front 144

How is a metabolic alkalosis generated?

Back 144

Loss of H+ or gain of HCO3-

Front 145

Because of the kidney's incredible efficiency of HCO3 excretion, metabolic alkalosis can only be sustained under what circumstance?

Back 145

Renal dysfunction

Front 146

Metabolic alkalosis is usually accompanied by what other imbalance?

Back 146

Hypokalemia

Front 147

Metabolic alkalosis can be brought on by volume depletion (ECF volume loss) or by what disease condition?

Back 147

Cushing's

Front 148

True or False. An acid-base derangements with compensation will show HCO3 and PCO2 moving in the same direction.

Back 148

True

Front 149

Where are the H+ chemoreceptors located?

Back 149

Carotid bodies and lower brainstem

Front 150

Metabolic acidosis (increased H+) creates what type of response from the chemoreceptors?

Back 150

An increase in the respiratory rate and a secondary decrease in PCO2

Front 151

An acid-base derangement on which the analytes move in opposite directions is termed what?

Back 151

Mixed acid-base disturbance

Front 152

Changes in the level of HCO3 by the kidneys can take how long to effect?

Back 152

24 hours

Front 153

How is base excess defined?

Back 153

The amount of strong acid of base necessary to titrate 1 liter of blood to a pH of 7.4 @ 37 C while PCO2 remains at 40 mmHg

Front 154

How is an anion gap calculated?

Back 154

(Na + K) - (Cl + HCO3)

Front 155

What is the value of a normal anion gap?

Back 155

less than or equal to 15

Front 156

Increased, unmeasured stray anions can indicate the presence of what conditions?

Back 156

Lactic acidosis, ketoacidosis

Front 157

Supplementation of bicarb can be calculated by what formula?

Back 157

BWT (kg) x 0.5 x (HCO3 norm - HCO3 actual)

Front 158

After calculating the amount of bicarb needed, how is it administered?

Back 158

50% as a bolus, remainder slowly over 12-24 hours

Front 159

ENDOTOXEMIA

Back 159

ENDOTOXEMIA

Front 160

Endotoxemia is a leading cause of death in horse with what condition?

Back 160

-colic
-colitis
-sepsis in foals

Front 161

Which disease is a complication of endotoxemia and is a co-factor for morbidity/mortality of many systemic diseases in horse?

Back 161

Laminits

Front 162

What is SIRS?

Back 162

Systemic Inflammatory Response Syndrome

Front 163

SIRS may follow development of endotoxemia and can lead to what conditions?

Back 163

-endotoxemic/septoic shock and w/o resucitative measures, multiple organ dysfunction (MODS) and death

Front 164

what type of structure is endotoxin?

Back 164

heat-stabile LPS

Front 165

LPS is a major structural cell wall component of which type of bacteria?

Back 165

Gram negative (incl. non-infectious species)

Front 166

In the LPS structure, which component is the toxic principle?

Back 166

Lipid A

Front 167

What is the function of the LPS D antigen?

Back 167

Virulence

Front 168

What innate barriers protect the horse fro endotoxins?

Back 168

-enterocyte muscosal cells
-mucus layer for prostaglandins
-tissue macrophages and Kupfer cells

Front 169

If endotoxin gains access to the bloodstream, what clinical signs may be seen?

Back 169

-fever
-leucopenia or leucocytosis
-coagulopathies
-hypertension
-shock, death

Front 170

Damage to the GI mucosa (and release of endotoxin into the system) can be caused by what?

Back 170

-local tissue hypoxia (volvulus, infarct, incarceration, systemic hypoxia, mechanical trauma, intraluminal acidification (grain overload)

Front 171

By what other methods can LPS enter the body?

Back 171

-inhalation
-administration of parenteral solution

Front 172

Once LPS is in the blood, it is targeted by what?

Back 172

Lipopolysaccharide Binding Protein (LBP) (synthesized in the liver, acute phase protein)

Front 173

What is the function of LBP?

Back 173

To carry LPS molecules to endotoxin-responsive immune cells (monocytes & macs), neutrophils, lymphocytes, endothelial cells

Front 174

CD14 and which toll like receptor are responsible for signaling an innate immune response?

Back 174

TLR4

Front 175

CD14 and TLR4 cannot trabslocate the LPS signlal to the immune cells without what protein?

Back 175

transmembrane protein MD2

Front 176

Which 2 inflammatory cytokines are responsible for the mediation of clinical signs in endotoxemia?

Back 176

TNF
IL1

Front 177

The clinical signs of endotoxemia are mediated by TNF and IL and what other cascades?

Back 177

-intravasucular coagulation pathway
-complement protein activation

Front 178

In the case of endotoxemia, what is the cause of moderate to severe neutropenia?

Back 178

Margination of PMNs and decreased extravasation of PMNs

Front 179

How can endotoxemia stimulate the extrinsic pathway of coagulation?

Back 179

By causing endothelial damage and exposing tissue factor (III)

Front 180

Loss of vascular tone (imbalance between vasoconstriction and dilation) leads to which 2 consequences?

Back 180

-systemic hypotension
-inadequate perfusion of tissues

Front 181

Increased plasma TNF is associated with increased mortality w/ acute GI in foals with what condition?

Back 181

Sepsis

Front 182

LPS cleaves phospholipid membranes. As a result, what cascades respond?

Back 182

-arachodonic acid cascade
-cycclooxygenase pathway (prostanoids, pg production)
-lipooxygenase pathway

Front 183

Endotoxins also cause the release of what other inflammatory mediators?

Back 183

-nitric oxide
-reactive oxygen species
-tissue factor stimulation
-complement
-neutrophil activation

Front 184

All of the response meechanisms lead to the hallmark of endotoxemia, which is.....

Back 184

Vascular permeability and endotoxemic shock

Front 185

What clinical signs of endotoxemia in a horse can be seen during the hyperdynamic shock stage (15045 mins)?

Back 185

-anorexia
-yawning
-sweating
-depression
-colic
-muscle fasiculation
-fever
-recumbency
-altered vascular permeability
-increased CRT

Front 186

What clinical signs are seen > 90 minutes post exposure to endotoxin?

Back 186

-diarrhea
-prolonged CRT
-dark red/purple mm
-3rd space fluid
-coagulopathy
-obtunded mentation
-hypothermia
-circulatory failure
-multi organ system failure
-laminits
-abortion

Front 187

What bloodwork results can you expect to see with endotoxemia?

Back 187

-neutropenia
-lymphopenia
-hyperglycemia
-hyperlactatemia
-thrombocytopenia
-prolonged aPTT
-prolonged PT
-increased FDP, d dimers
-decreased fibrinogen concentration

Front 188

What one potential drug looks promising for treating endotoxemia?

Back 188

Acvtivated protein C

Front 189

What is the best evidence for survival of endotoxemia?

Back 189

-early aggressive cardiovascular resuscitation
-O2
-iv fluids
-pressor tx
-packed rbc's

Front 190

What are the goals of early endotoxemia therapy in horses?

Back 190

-cardiovascular resusciation
-laminitis prevention
-removal of causes of endotoxin
-neutralization of fre circulating LPS
-inhibition of LPS mediated inflammation

Front 191

Cardiovascular resuscitaion includes the use of which fluids?

Back 191

-hypertonic saline
-colloids (hetastarch, plasma)
-crystalloids

Front 192

What effects will hypertonic saline have in the tx of endotoxemia?

Back 192

-transient increase in vascular volume
-suppressed degranulation of PMNs (decreased ROS)
-prevents PMNs-endothelial adhesions
-blocks nuclear transcription of inflammatory cytokines

Front 193

What benefit does hetastarch have in treating endotoxemia?

Back 193

Higher COP than plasma, increases vascular volume

Front 194

What must you be cautious about when using hetastarch?

Back 194

prolonged aPTT when high doses are used

Front 195

What benefits are there in using equine frozen plasma?

Back 195

-excellent source of albumin
-anti-endotoxins
-clotting factors

Front 196

What are the drawbacks to plasma?

Back 196

-requires time to thaw
-requires time to administer
-expensive

Front 197

Which fluid is used for resuscitation...colloids or crystalloids?

Back 197

Both

Front 198

What prophylactic steps can be taken to prevent laminitis?

Back 198

-cryotherapy
-NSAIDs

Front 199

What is the advantage to cryotherapy?

Back 199

50% reduction in the metabolic rate with a 10C drop in temp

Front 200

True of False, cryotherapy is beneficial at all stages of endotoxemia?

Back 200

False- before clinical signs are seen

Front 201

What is the goal of low dose NSAID therapy?

Back 201

Prevent LPS associated prostanoid production

Front 202

What is the goal of high NSAID therapy?

Back 202

Cox inhibitor, excellent visceral analgesia

Front 203

What is the drawback to using NSAIDs?

Back 203

-delayed muscosal healing
-toxicity (renal, gi)

Front 204

What causes of endotoxn can be removed?

Back 204

-sx to remove ischemic bowel
-drainage of septic pleural/peritoneal/uterine fluid cavities

Front 205

Are broad spectrum antibiotics indicated for endotoxemia?

Back 205

Yes, but with caution

Front 206

Under what conditions do you need to be cautious when using antibiotics?

Back 206

-horse < 3months old (maternal ab)
-suspicion of clostridial or antimicrobial associated enteritis
-degenerative left shift or PMN/leukocytes < 1000uL
-evidence of dyshemopoiesis

Front 207

What treatment would neutralize free circulating enodtoxemia?

Back 207

-plasma tx
-polymixin B

Front 208

Polymixin B can have what toxic side effect?

Back 208

-renal dysfunction

Front 209

What drugs inhibit endotoxemia mediated inflammation?

Back 209

-2% lidocaine CRI
-NSAIDs
-pentoxyfylline
-DMSO

Front 210

What effects does lidocaine have in the tx of endotoxemia?

Back 210

-anti-inflammatory
-analgesic
-prevents retardation of mucosal healing when used w/ Banamine

Front 211

What effects does pentoxifylline have?

Back 211

Suppresses inflammatory cytokines, rheologic agent, inhibits TNFm promotes PGI1

Front 212

What effect dose DMSO provide in the tx of endotoxemia?

Back 212

-free radical scavenger
-anti inflammatory
-prophylactic tx of laminitis

Front 213

What is a potential side effect of DMSO?

Back 213

Hemolysis

Front 214

What are the best steps to take in dealing with endotoxemia?

Back 214

-recognize patients at risk
-restore perfusion/oxygenation
-ameliorate clinical signs
-prevent laminitis

Front 215

LAMINITIS

Back 215

LAMINITIS

Front 216

What is the definition of laminitis?

Back 216

Inflammation of the laminae

Front 217

What does laminitis cause?

Back 217

Degeneration, necrosis and inflammation of the dermal and epidermal laminae of the hoof wall of horses

Front 218

Which lamellae of the foot interdigitate?

Back 218

Sensitive and insensitive lamellae

Front 219

What is the function of the lamellae?

Back 219

Hold PIII in close proximity to the hoof
-act as a suspension mechanism

Front 220

What kind of disease conditions initiate laminar changes?

Back 220

Any disease that decreases laminar perfusion and protein synthesis

Front 221

The rigidity of the hoof wall can lead to what complication with the swelling of the laminae?

Back 221

Pressure necrosis

Front 222

Hours before the onset of clinical signs, what happens to the sensitive and insensitive lamellae?

Back 222

They separate

Front 223

Failure of the laminae can lead to what disastrous condition?

Back 223

MODS

Front 224

What is the #1 risk factor for laminitis for patients in the ICU?

Back 224

Endotoxemia

Front 225

How can endotoxemia lead to laminitis?

Back 225

GI disease may lead to translocation of endotoxin

Front 226

What is the response of the body to LPS?

Back 226

Up-regulation of inflammatory cytokines

Front 227

True or False- endotoemia by itself can cause laminitis.

Back 227

False- not by itself

Front 228

What other systemic condition can lead to laminitis?

Back 228

Septic metritis

Front 229

What is contra-lateral limb laminitis?

Back 229

Excess weight bearing on a limb due to injury in the opposite limb (support limb laminitis)

Front 230

What type of dietary changes can lead to laminitis?

Back 230

Increase in CHO, grain overload (incomplete pre-cecal digestion), grazing lush spring grass

Front 231

What types of horses can get laminitis from grazinf lush spring grasses?

Back 231

Ponies
Horses w/ metabolic syndrome

Front 232

Laminitis can be caused by what types of endocrinopathies?

Back 232

-equine Cushing's
-equine metabolic syndrome
-glucocorticoid excess
-insulin resistance
-impaired glucose utilization
-inflammatory up-regulation
-hyperinsulinemia

Front 233

Ingesting what plant/tree can lead to clinical signs of laminitis?

Back 233

Black walnut

Front 234

Where might a horse encounter black walnut?

Back 234

In shavings for bedding

Front 235

What are the clinical signs of ACUTE laminitis?

Back 235

-bounding digital pulses
-heat in the hoof capsule
-softness of coronary band
-shifting weight
-refusal to pick up feet/or walk
-pain
-tachycardia/tachypnea
-anorexia/depression

Front 236

What grading system is used to rank the severity of laminitis?

Back 236

Obel grading

Front 237

What is the importance of radiographs during an acute laminits?

Back 237

Can be used as a baseline

Front 238

Radiographically, what may be the only indication of laminitis inflammation?

Back 238

Thickening of the dorsal foot wall

Front 239

What are the effects of laminitis on PIII?

Back 239

Leads to the detachment of P3 from the hoof wall
rotation
sinking

Front 240

Ideally, when should laminitis treatment begin?

Back 240

Prophylactically

Front 241

What are the goals of laminitis treatment?

Back 241

-eliminate the primary cause
-promote digital circulation
-reduce tension on the laminae
-minimize digital inflammation and pain

Front 242

True or false...the acute phase of laminitis is a medical emergency.

Back 242

TRUE!

Front 243

Prophylactic treatment for laminitis includes what 3 components?

Back 243

-cryotherpy
-anti-inflammatories
-sole support

Front 244

When should cryotx be started?

Back 244

before the clinical signs of laminitis

Front 245

Which drugs are sued as anti-inflammatory prophylaxis?

Back 245

2% lidocaine CRI
NSAIDs

Front 246

What type of sole support is used for laminitis?

Back 246

-removal of metal shoes
-apply styrofoam cushion

Front 247

What type of bedding should be used for horses with laminitis?

Back 247

-deep sand
-peat moss

Front 248

Pain management for laminitis should take what approach?

Back 248

Multi-modal

Front 249

CHRONIC laminitis is a result of what?

Back 249

Abnormal hoof conformation

Front 250

What are some conditions that lead to mis-shapened feet?

Back 250

-growth at toe (ski shoes)
-lack of growth at heel
-growth rings prominent, not parallel
-sole flattened

Front 251

What radiographic changes might be seen in a case of chronic laminitis?

Back 251

-osteomyelitis
-deformation of PIII

Front 252

What types of lifetime foot problems can be expected with chronic laminitis?

Back 252

-recurring foot abscessation
-hoof cracks and chips
-tendency towards sole bruising

Front 253

What treatment can be used to reduce rotation of the coffin bone?

Back 253

raise the heel

Front 254

Therapy for chronic laminitis includes what?

Back 254

-good foot care
-balances shoeing
-sole pads
-tx of thrush
-good environment

Front 255

What is the prognosis for laminitis?

Back 255

It is for a lifetime

Front 256

What is the capacity of the equine cecum?

Back 256

30 liters

Front 257

What is the capacity of the equine large colon?

Back 257

60 liters

Front 258

What are some of the clinical signs of colic?

Back 258

-kicking at belly
-pawing
-lying down
-looking at sides
-curling lips
-playing in water
-grinding teeth
-refusing feed
-change in attitude
-decreased fecal output

Front 259

What are the clinical signs of severe, acute colic?

Back 259

-down and rolling
-evidence of rolling
-breathing hard
-sweating
-abdominal distention

Front 260

Why do you inspect the feces in reference to a case of colic?

Back 260

For amount and consistency

Front 261

Why is a rectal palpation performed on a horse with colic?

Back 261

Identify changes in visceral organs

Front 262

What are 2 additional steps to take prior to performing a rectal?

Back 262

Wrap tail
Use copious lube

Front 263

What is a potential serious complication of rectal palpation?

Back 263

Rectal tear

Front 264

How many grades of rectal tears are there?

Back 264

I- IV

Front 265

A grade I tear includes what?

Back 265

Mucosa and submucosa

Front 266

What constitutes a Grade II tear?

Back 266

Muscularis only

Front 267

A rectal tear with a grade IIIa/b includes which layers?

Back 267

All layers except serosa

Front 268

What constitutes a grade IV rectal tear?

Back 268

Full thickness, all layers

Front 269

What color is normal peritoneal fluid?

Back 269

Clear transudate to straw/yellow

Front 270

TP of peritoneal fluid should normally be what?

Back 270

< 2g/dl

Front 271

Serosanguinous fluid from an abdominocentesis indicates what conditions?

Back 271

-bowel devitilization
-splenic puncture
-sub cu blood vessel

Front 272

In the case of a bowel rupture, you would expect peritoneal fluid to have what color?

Back 272

Green

Front 273

What color is peritoneal fluid in the case of peritonitis?

Back 273

Thick orange

Front 274

What lenght of endoscope is needed for a horse?

Back 274

1 M and 3 M

Front 275

True or False. Laporoscopy is considered a diagnostic tool.

Back 275

True

Front 276

A routine GI examination should include what imaging modality?

Back 276

U/S

Front 277

Which U/S probe is used for equine GI?

Back 277

3-5 mHz

Front 278

Where do you place the U/S probe to located the stomach?

Back 278

-right side
-9-13 ICS

Front 279

Where is the duodenum located?

Back 279

-right side
-ventral to the caudal pole of the right kidney

Front 280

How do you distinguish the large colon from other organs on U/S?

Back 280

look for the hautra/ sacculations

Front 281

Which imaging modality is useful for diagnosing bone disease?

Back 281

Nuclear medicine

Front 282

How are full thickness biopsies obtained?

Back 282

-ventral midline celiotomy
-laporoscopy

Front 283

Along with evaluating the amount and consistency of feces, what else do you examine the feces for?

Back 283

Sand
Parasites

Front 284

When is an absoprtion test indicated?

Back 284

In chronic weight loss

Front 285

What shape does a normal absorption uptake curve have?

Back 285

Inverted V

Front 286

True or False. The equine esophagus is covered by a thin serosa.

Back 286

False.,..not covered at all except for a short distance between the diaphragm and stomach

Front 287

What is the benefit of the esophagus being attached to surrounding tissues?

Back 287

Allows movement of the esophagus during swallowing

Front 288

What types of muscle comprise the equine esophagus?

Back 288

Cranial 2/3 is skeletal

Caudal 1/3 smooth

Front 289

What muscle forms the cranial esophageal muscle?

Back 289

Cricopharyngeus

Front 290

Why can't horses vomit?

Back 290

-poorly developed vomition center
-high interluminal pressure of the distal esophagus

Front 291

What is a primary clinical sign of esophageal disease in a horse?

Back 291

Ptyalism -hypersalivation

Front 292

What should you be aware of when palpating the esophagus?

Back 292

-creptius (emphysema)
-swelling

Front 293

What is the value of plain radiographs in evaluating the esophagus?

Back 293

-localize evidence of obstruction
-gas opacity between fascial planes indicating perforation

Front 294

Why would you perform barium studies?

Back 294

To outline intraluminal obstruction/strictures

Front 295

A complete esophageal exam will include what procedure?

Back 295

Endoscopy

Front 296

What imaging procedure would you use to evaluate the motility of the esophagus?

Back 296

Fluoroscopy

Front 297

What is primary choke?

Back 297

Simple luminal obstruction

Front 298

What are some causes of primary choke?

Back 298

-roughage
-foreign bodies: corn cobs, potatoes, apples

Front 299

What are some intramural causes of choke?

Back 299

-tumor
-strictures
-diverticula
-cysts,
-vascular ring anomalies

Front 300

What is the most common clinical sign of esophageal obstruction?

Back 300

Ptyalism and frothy nasal discharge with feed and saliva

Front 301

What other signs of obstruction may be seen?

Back 301

-may stand with head and neck extended
-gagginr
-retching
-coughing

Front 302

Why would you see an electrolyte imbalance in a horse with choke?

Back 302

Loss of saliva

Front 303

Definitive information about the cause of esophageal obstruction can be made with what technique?

Back 303

Endoscopy

Front 304

Where do most esophageal obstructions occur?

Back 304

At the sites of narrowing
-cervical esophagus
-heart base/thoracic inlet
-terminal esophagus

Front 305

What is the primary goal in the treatment of choke?

Back 305

To relieve the impaction

Front 306

Why is the horse sedated to treat for choke?

Back 306

To prevent aspiration

Front 307

An attempt to dislodge the obstruction is made with what?

Back 307

A NG tube

Front 308

If the NG tube/lavage method does not clear the obstruction, what method is tried?

Back 308

Chemically relax the esophagus and provide isotonic IV fluids

Front 309

Why is a horse at risk for re-obstruction?

Back 309

-dilatation of the esophagus proximal to the site of obstruction
-traumatic mucosal injury
-esophagitis

Front 310

What percentage of horses will experience re-obstruction post resolution of the choke?

Back 310

40%

Front 311

True or False. Complications of choke include metabolic acidosis from prolonged losses of Na and Cl.

Back 311

False, metabolic alkalosis

Front 312

What other complications might be encountered?

Back 312

-esophageal ulceration
-stricture
-perforation
-aspiration pneumonia
-mega esophagus

Front 313

Why are broad spectrum antibiotics indicated when lavage alone doesnt resolve a choke?

Back 313

Due to possible aspiration pneumonia

Front 314

Some clinicians recommend the administration of what drugs to reduce the development of strictures?

Back 314

NSAIDs (Banamine, Bute)

Front 315

What is the cause of esophageal sticture?

Back 315

Circumferential mucosal erosion related to choke (also from corrosive medicinal agents and trauma, congenital strictures have been reported

Front 316

In what timeframe does maximal esophageal stricture occur?

Back 316

Within 30 days post obstruction

Front 317

Is Bougienage helpful?

Back 317

No, not in horses

Front 318

Esophageal perforation can occur as a result of choke, but also from what other related conditions?

Back 318

-external trauma
-iatrogenic perforation from exccesive force using a NG tube

Front 319

How are perforations treated?

Back 319

-debridement and lavage
-antibiotics
-tetanus prophylaxis
-esophageal rest (use wound for esophagotomy)

Front 320

Hypomotility of the esophagus results in what condition?

Back 320

-dilation
-megaesophagus

Front 321

Acuqired megaesophagus is a result of what?

Back 321

Primary or secondary esophageal obstruction

Front 322

Megaesophagus has also be associated with reflux esophagitis and what types or neuro disease?

Back 322

-equine protozoal myeloencephalitis
-equine herpes virus myeloencphalitis
-idopathic vagal neuropathy

also with pleuropneumonia, C. botulinum and grass sickness

Front 323

Is megaesophagua a functional or mechanical obstruction?

Back 323

Functional

Front 324

Definitive dx of esophageal hypomotility requires what technique?

Back 324

barium fluoroscopy

Front 325

What exam can rule out a myopathy as a cause of megaesophagus?

Back 325

EMG

Front 326

Treatment of megaesophagus can include giving metaclopramide or bethanecol (if reflux eosphagitis is present) to have what effect?

Back 326

-increase the tone of the lower esophageal sphincter
-reduce reflux

Front 327

What is the prognosis of congenital megaesophagus?

Back 327

Poor

Front 328

The equine stomach is divided into 4 regions based on what?

Back 328

Type of mucosal lining

Front 329

What are the 4 types of stomach mucosa?

Back 329

-non-glandular stratified squamous epithelium (continuous w/the esophagus)
-cardiac epithelium
-gastric mucosa
-pyloric mucosa

Front 330

What structure separates the non-grandular and cradiac regions from the glandular mucosa?

Back 330

Margo plicatus

Front 331

Which cells of the gastric mucosa secrete HCL?

Back 331

Parietal cells

Front 332

What 3 receptors must bind concurrently for the production of HCL?

Back 332

-gastrin
-ACH
-histamine 2

Front 333

The stratified squamous epithelium layer is impermeable to HCL until the pH falls below what level?

Back 333

2.5

Front 334

Which cells secrete mucus and bicarb that form a gel-like substance to titrate HCL before it reaches the gastric lumen?

Back 334

Goblet cells

Front 335

Additional gastric mucosal protection is provided by what secretions?

Back 335

Prostaglandins

Front 336

What is the benefit of horses being constant grazers?

Back 336

Maintains a feed bolus which helps protect the mucosa from HCL

Front 337

Lesions found in the gastric squamous or glandular mucosa, ulcerations, gastritis, gastic-emptying disorder and reflux disorders as all grouped under what heading?

Back 337

Equine Gastric Ulcer Syndrom (EGUS)

Front 338

In adult horses, ulcer dz is commonly associated with which mucosa?

The foal?

Back 338

Adult- squamous mucosa

Foals- glandular and pyloric regions

Front 339

The prevalence of EGUS is high in horses, especially under what conditions?

Back 339

Training--- 70-90% in racehorses

Front 340

Along with increased exercise, what other factors contribute to EGUS?

Back 340

-feeding pratices
-management
-NSAIDs

Front 341

What feeding practice exposes the horses mucosa to HCL?

Back 341

Meal feeding (2 X day), stall confinement

Front 342

What effect do NSAIDs have in EGUS?

Back 342

Disables production of protective prostaglandins

Front 343

Does H. pylori contribute to EGUS?

Back 343

The antibody has recently been reported as being present in horses

Front 344

What are the clinical signs of EGUS?

Back 344

-loss of body weight
-poor hair coat
-poor body condition
-poor appetite
-intermittent colic

Front 345

The dx of EGUS is based on what?

Back 345

-age-related clinical signs
-edoscopic exam
-response to tx

Front 346

Where do most ulcers form in adult horses in training?

Back 346

Along the margo plicatus

Front 347

Does EGUS cause anemia or hypoproteinemia?

Back 347

No

Front 348

What is the goal of EGUS tx?

Back 348

Alleviate discomfort by neutralizing acid secretion

Avoid NSAIDs

Front 349

What drug class is used to suppress acid production?

Back 349

H2 antagonist
ranitidine, cimetidine, famotidine and nizatidine

Front 350

What is the mechanism of action of H2 antagonists?

Back 350

Interfers with histamine stimulation of HCL secretion from partietal cells of gastric mucosa

Front 351

What is another method of supressing HCL secretion?

Back 351

Proton-pump inhibition

Front 352

How do proton pump inhibitors work?

Back 352

Block the H+ K+ ATPase pump on the parietal cells

Front 353

Which drug is a proton pump inhibitor?

Back 353

Omeprazole

Front 354

Is Sucralfate helpful in healing gastric ulcers in horses?

Back 354

No

Front 355

Why is true gastric impaction an infrequent diagnosis in a horse?

Back 355

It is a difficult dx to make

Front 356

Which foodstuffs are particularly indicated in gastric impaction?

Back 356

Beet pulp and bran..become dessicated in the stomach

Front 357

other than a surgical dx, how is gastric impaction diagnosed?

Back 357

Endoscopic documentation of a feed bolus in the stomach 12-24 hours following ingestion

Front 358

What is the tx for gastric impaction?

Back 358

Lavage via NG tube, also give dioctyl sodium succinate (DSS) as a detergent

Front 359

Gastric impaction may be a result of which more severe disease see in Britain and South America?

Back 359

Grass sickness (equine dysautonomia)

Front 360

What can potentially gas a gastric rupture?

Back 360

Secondarily to gastric distention from ingesta, fluid or gas

Front 361

Is gastric rupture in the adult horse treatable?

Back 361

No-a catastrophic injury with excessive contamination

Front 362

What is the most common neoplasm to affect the equine stomach?

Back 362

Squamous cell carcinoma

Front 363

What are the presenting clinical signs of neplasm of the stomach?

Back 363

-weight loss
-anemia
-nasal reflux
-colic

Front 364

What are the components of the equine small intestinal tract?

Back 364

-duodenum
-jejunum
-ileum

Front 365

What is the approximate total length of the equine small intestine?

Back 365

70 feet

Front 366

How much of the small intestine can be surgically resected?

Back 366

roughly 1/2

Front 367

What additional GI structures are located within the duodenum?

Back 367

Major and minor papilla of common bile duct

Front 368

Which small intestine segment is the longest?

Back 368

Jejunum

Front 369

What structure is located at the distal end of the ileum?

Back 369

Cecum

Front 370

How is the ileum differentiated from other segments of small intestine?

Back 370

Non-vascular, antimesenteric band (ileocecal fold) which is contiguous with the dorsal band of the cecum

Front 371

Which diagnostic technique is most useful in evaluating the small intestines?

Back 371

U/S

Front 372

How does IBD in horses differ than in humans?

Back 372

Humans- neutrophilc inflammation
Horses- neutrophil is the primary effector cell but the dz is defined by other granulocytic cells (eosinophils, bashophils, lymphos, macs)

Front 373

Horses with IBD present with weight loss and diarrhea. How do horse present with (a new condition) idiopathic focal eosinophilic enteritis (IFEE)?

Back 373

Signs of acute colic pain but no protein losing enteropathy

Front 374

True or False, a horse with traditional IBD of the SI will not have diarrhea.

Back 374

True

Front 375

Why would a horse with IBD present with peripheral edema?

Back 375

Hypoproteinemia- enteric protein loss

Front 376

What change might U/S show in a case of IBD?

Back 376

increased intestinal wall thickness (>5mm)

Front 377

What would a glucose absorption test curve look like in the case of IBD?

Back 377

Flat- malabsorption

Front 378

In IBD, inflammatory cells infiltrate the intestinal tract, making what procedure a useful tool in indentifying IBD?

Back 378

Rectal mucosal bx

Front 379

How is a definitive dx of IBD made?

Back 379

Bx of small or large intestine via laparoscopy or celiotomy

Front 380

How successful is tx of IBD in horses?

Back 380

Largely unsuccessful

Front 381

Do horses with IBD or IFEE have a better chance at recovery?

Back 381

IFEE- typically respond to surgical decompression

Front 382

Granulomatous enteritis tends to affect which horses?

Back 382

Young, standardbred

Front 383

On hisotpath, what cells are primarily seen in granulomatou enteritis?

Back 383

macrophages

Front 384

What is the prognosis of a horse with granulomatous enteritis?

Back 384

Poor

Front 385

Which non-infectious inflammatory bowel dz of young horses has dermatological effects?

Back 385

MEED
Multisystemic Eosinophilic Epitheliotropic Enterocolitis Dz

Front 386

True or False...lymphocytic/plasmacytic enteritis is a common disease of horses of all ages?

Back 386

False- it's rare

Front 387

Lawsonia intracellularis causes what disease of the intestine of mammals and avian species?

Back 387

Proliferative enteropathy

Front 388

In pigs, what name is Lawsonia as it causes proliferation of the SI?

Back 388

garden hose gut

Front 389

How does the Lawsonia bacterium infection occur, and in what horses?

Back 389

Fecal-oral
affects weanling foals

Front 390

What factors increase the chances of infection?

Back 390

-overcrowding
-ration changes
-transport
-weaning

Front 391

What are the 2 hallmarks of Lawsonia?

Back 391

-hypoproteinemia
-grossly thickened SI with mucosal ulceration

Front 392

Mucosal proliferation of the SI crypt cells typically affect which areas of the SI?

Back 392

Terminal jejunum and ileum

Front 393

What is the appearance of the SI epithelium in an infection with Lawsonia?

Back 393

Thickened, corrugated

Front 394

What effect does this thickening have on the SI function?

Back 394

-decreased brush border enzyme activity
-decreased absorptive capacity
-weight loss
-malabsorption diarrhea
-hypoproteinemia

Front 395

What is the primary differential dx for Lawsonia?

Back 395

R equi

Front 396

What are the clinical signs of Proliferative Enteritis seen in foals 4-6 months of age?

Back 396

-Ill thrift: poor hair coat, pot bellied, dimished stature, poor grwoth rate

-weight loss

-peripheral edema

-diarrhea

-colic

Front 397

Why do horses affected with PE show hyperfibrinogenemia?

Back 397

Chronic inflammation

Front 398

What other blood results would you see in a case of PE?

Back 398

-modearte hypoproteinemia
-hypoalbuminemia
-mild anemia
-hypoglobulinemia
-neutrophilic leukocytosis
-pre reanal azotemia

Front 399

U/S exam of the abdomen may show what sign of PE?

Back 399

Thickened walls of SI tract (>5mm)

Front 400

When are most cases of Lawsonia PE seen?

Back 400

August to January

Front 401

What is the gold standard dx for Lawsonia?

Back 401

Isolation and culture from tissue

Front 402

What stain is used to visualize Lawsonia?

Back 402

Warthin-Starry stain

Front 403

What is the tx for PE?

Back 403

-antimicrobial tx targeting intracellular pathogens and supportive care
-tetracylcine (Ocytet/Doxy)

Front 404

What is the prognosis for a foal with Lawsonia?

Back 404

Good, 93% recovry, may be small in stature compared to other foals

Front 405

What does enteritis mean?

Back 405

Inflammatory condition of the small intestine.

Front 406

What are the cardinal signs of inflammatory lesions?

Back 406

-fever
-endotoxemia
-depression

Front 407

Acute pain is due to what?

Back 407

-intestinal wall inflammation
-edema
-necrosis
-infarction

Front 408

What are the cardinal clinical findings of enteritis?

Back 408

-fluid distended loops of small intestine on U/S exam
-on rectal palpation
-gastric reflux

Front 409

How is duodentitis-proximal jejunitis (DPJ) characterized?

Back 409

-inflammation and edema of the duodenum and proximal jejunum, excessive fluid and electrolyte secretion into the small intestine and consequently, high volumes of enterogastric reflux

Front 410

True or false with DPJ horses have copious reflux and abdominal discomfort without mechanical obstruction to flow of ingesta.

Back 410

True

Front 411

Inflammation within in the SI causes what kind of obstruction?

Back 411

A functional obstruction of motility due to dysregulation of the myenteric plexus )or enteric nervous system)

Front 412

What is a common finding of DPJ in sx or necropsy?

Back 412

Serositis: bright red to dark red petechial and ecchymotic hemorrhages on the serosal surface of the proximal SI

Front 413

What factors are used to help determine which horses with SI obstruction need sx intervention or medical tx?

Back 413

-degree of pain and response to gastric decompression
-fever
-changes in bloodwork and peritoneal fluid parameters

Front 414

Horses with DPJ have what type of results when an NG tube is passed?

Back 414

-Large amounts of typically odrous fluid, orange-brown in color

Front 415

What hallmark of DPJ is seen when a NGT is passed?

Back 415

-horses are less colicky and appear depressed

Front 416

Horses with DPJ have what other clinical signs?

Back 416

-fever
-mild to moderate colic
-dehydration
-signs of endotoxemia, hypovolemia, increased borborygmi, elevated heart and respiratory rates

Front 417

What is the appearance of the SI with DPJ as seen on U/S?

Back 417

Variable sized and shaped distended loops of SI, typically with increased wall thickness (>5-6mm)

Front 418

Horses with ischemic/necrotic bowel have abnormal peritoneal fluid parameters such as elevated total solids, elevated nucelated cell count and abnormal color (serosanguinous). How does DPJ compare to this?

Back 418

DPJ abdominal fluids may be turbid, dark yellow to orange but rarely serosanguinous, mild elevated cell count and elevated total solids

Front 419

DPJ may have an infectious cause such as what?

Back 419

Salmonella spp, Clostridium spp.

Front 420

When is definitive confirmation of DPJ made?

Back 420

At sx or necropsy

Front 421

What is the tx for DPJ?

Back 421

-support tx centered of frequent gastric decompression (indwelling NGT) and IV fluid replacment

also tx for hypoproteinemia, antiendotoxin, antiinflammatory tc, analgesia etc

Front 422

What are the 2 causes of GI Ileus?

Back 422

-DPJ (most common)
-POI post op ileus following general anesthesia

Front 423

How does SI sx cause ileus?

Back 423

-handling of the bowel
-distention of the bowel proximal to obstruction

Front 424

Non-abdominal can result in GI ileus....how?

Back 424

Cecal dysfunction for general anesthesia

Front 425

30% of hoses undergoing SI sx will have POI, what factors affect this situation?

Back 425

-length of resection
-age
-PCV at admission
-duration of anesthesia

Front 426

Why does POI increase morbidity and mortality?

Back 426

-adhesion formation (chr. colic)
-lamintis

also a big financial burden

Front 427

POI can occur in any post op pt, how soon after sx do clinical signs of POI develop?

Back 427

24-96 hours post op

Front 428

What clinical signs of POI should you watch for?

Back 428

-tachycardia
-tachypnea
-colic
-decreased manure production
-decreased borborygmi

Front 429

How can you monitor a horse for POI development?

Back 429

Serial U/S exams

Front 430

How do you dx POI?

Back 430

-serial U/S exam
-rectal exam
-peritoneal fluid
-pass NG tube (20L in 24 hrs or 8L at any one time)
-volume of reflux should taper
-attempt to r/o mechanical obstruction

Front 431

What factors would make you suspicious of POI?

Back 431

-hx of sx intervetion
-/+ resection
-degree of inflammation of of GI tract
-distention of proximal bowel


also concern about mechanical re-obstruction
development of peritonitis

Front 432

What is the TX for POI?

Back 432

Same as for DPJ:
-gastric decompression
-monitor fluids in and out
-anti-inflammatory tx
-prokinetic Tx

Front 433

What is one of the serious complications of POI?

Back 433

Adhesion formation

Front 434

What is peritonitis?

Back 434

An inflammatory condition of the mesothelial lining of the peritoneal cavity

Front 435

Where is the mesothelial lining located?

Back 435

-1 cell layer thick
-visceral/parietal surfaces
-lines internal organs
-has a large surface area

Front 436

What is the pathophysiology of peritonitis?

Back 436

-initial insult
-release of vasoactive mediators: histamine & serotonin
-increased vascular permeability
-transudation
-protein, fluids, cells

Front 437

Macrophages stimulate the inflammatory process leading to what?

Back 437

-lysosomal degranulation
-fibrin deposition
-translocation of bacteria

Front 438

The increased peritoneal permeability leads to shifting of fluid and electrolytes which can cause what?

Back 438

-dehydration
-hypovolemia

Front 439

Endotxoemia, bacteremia and shock can result from what component of peritonitis?

Back 439

Intravascular re-entry of pro-inflammatory substances and bacteria

Front 440

What is the difference between primary and secondary peritonitis?

Back 440

Primary: no identifiable inciting cause

Secondary: caused by
-infection
-trauma
-chemical
-parasitic
-visceral disease
-abdominal surgery
-neoplasia

Front 441

Aseptic peritonitis is defined as what?

Back 441

-mechanical or chemical irritation
(urine/bile/foreign material)
-surgery

Front 442

What does septic peritonitis imply?

Back 442

-bacterial foci within the peritoneum

Front 443

What are some of the sources of septic peritonitis?

Back 443

-bowel perf
-penetrating wounds
-rectal tears
-dehiscence
-uterine rupture
-breeding accident
-bacetremia

Front 444

What is the most common cause of septic peritonitis?

Back 444

Surgical contamination

Front 445

What are the clinical signs of peritonitis?

Back 445

-pyrexia
-diarrhea
-anorexia
-dehydration
-abdomen pain
-tachycardia/pnea
-ileus
-depression
-abd distention
-abnormal rectal exam findings

Front 446

How would you Dx peritonitis?

Back 446

-CBC and fibrinogen
-rectal exam
-abd U/S
-peritonel paracentesis

Front 447

On a CBC what is the difference between an acute and a chronic peritonitis?

Back 447

-acute: neutropenia w/ toxic left shift, normal fibrinogen

chronic: neutrophilia w/ increased fibrinogen

Front 448

What would you expect to see on the analysis of peritoneal fluid from peritonitis?

Back 448

-color/clarity altered
-markedly elevated WBS
-increased TP

do C&S and cytology

Front 449

Recent surgery complicates the dx of peritonitis, what test would you run to help?

Back 449

Blood gas analysis of the peritoneal fluid

Front 450

How does the blood gas of septic peritoneal fluid compare to serum blood gas?

Back 450

-glucose < 50 points lower than serum
-elevated lactate
-very low pH

Front 451

What cause these changes in the blood gas values of peritoneal fluid?

Back 451

Bacteria metabolize glucose and produce lactate as by-product, lowering pH

Front 452

What is the Tx for peritonitis?

Back 452

-Abx
-anti-inflammatory tx
-anti-endotoxemic/laminitis tx
-maintain hydration
-e-lyte balance
-consider nutrition
-monitor protein loss into the abd

Front 453

What controversial tx is sometimes used to tx peritonitis?

Back 453

Peritoneal lavage

Front 454

What is the prognosis of peritonitis?

Back 454

-variable
-depends on underlying etiology
-complications (laminits, adhesions)

Front 455

What is meant by the term small bowel obstruction?

Back 455

-occlusion of the small bowel lumen of the instestine without compromise to the associated blood supply (non-strangulating lesion)

Front 456

What is a functional obstruction?

Back 456

Simple obstructions which are nueromuscular in nature and result in the lack of propulsive muscle activity (ie DPJ)

Front 457

What is a mechanical obstruction?

Back 457

Physical occlusion of the intestinal lumen

Front 458

The severity of pain from an obstruction is related to what?

Back 458

-degree of obstruction and the amount of intestinal distention proximal to the obstruction

Front 459

What is a strangulating obstruction?

Back 459

Occlusion of the intestinal lumen as well as the blood supply to that segment of SI

Front 460

Horse with strangulating obstructions often develop what conditions?

Back 460

-endotoxemia
-hemoconcentrated
-dehydration

Front 461

What is the course of action for a horse with a strangulating obstruction?

Back 461

Surgery

Front 462

Which ascarid impaction occurs in horses < 1 year of age?

Back 462

Parascaris equoroum

Front 463

How do foals become impacted?

Back 463

Following oral paste deworming with an antihelmintic in heavily parasitized individuals...adult worms live in Si lumen and die en masse, causing luminal obstruction

Front 464

What are some of the clinical signs of impaction?

Back 464

-mild to moderate colic pain
-gastric reflux
-fever, endotox
-inflammatory mediators lead to fever, tachcardia/pnea, poor perfusion, shock

Front 465

What is the goal of tx for ascarid impaction?

Back 465

Medical
-gastric decompression
-gastric lavage
-anti-inflammatory meds

Front 466

What conditions might a foal with ascarid impaction develop?

Back 466

-intestinal necrosis
-rupture
-peritonitis
-adhesion

Front 467

What is the prognosis for a foal with ascarid impaction?

Back 467

Guarded due to the sever inflammatroy response from the death of the parasite. Medical tx is a better prognosis than sx

Front 468

How can ascarid impaction be avoided?

Back 468

use a slow kill antihelmentic

Front 469

Where, geopgraphically, does ileal impaction occur, and why?

Back 469

Southeast US due to luminal obstruction of the ileum with dry feed matter

Front 470

Which feed is most likely to cause ileal impaction?

Back 470

Coastal Bermuda grass hay

Front 471

Ileal impaction has also been associated with what other condition?

Back 471

Tapeworm infestation due to irritation at the ielocecal junction

Front 472

What clinical signs are associated with ileal impaction?

Back 472

SI obstruction signs
-colic that is acute, mild to severe
-not all will show reflux
-reduced intestinal sounds
-distended bowel loops on rectal exam

Front 473

What medical tx might be of use early in the impaction?

Back 473

-mineral oil (via NGT)
-analgesics
-IV fluids

Front 474

What sx approach can be taken for ileal impaction?

Back 474

Removal via SI enterotomy

Front 475

What is the term for the proximal (oral) segment of an SI intussusception?

Back 475

Intussusceptum

Front 476

What is the term for the distal segment of an SI intussusception?

Back 476

Intussuscipiens

Front 477

What is the most common location for a SI intussusception?

Back 477

ileocecal

Front 478

In what age of horse is intussusception seen?

Back 478

< 3 years, foals and weanlings

Front 479

Sx manipulation of an intussusception may be possible except in the ileocecal region....how is this handled?

Back 479

resection or baypass of the ileum

Front 480

What is the U/S appearance of an intussusception?

Back 480

Bull's-eye, 2 concentric rings in a circular area

Front 481

Necrosis of the distal ileal stump may result in what conditions?

Back 481

-septic peritonitis
-abscessation
-ahesions

Front 482

What is a SI volvulus?

Back 482

twisting of the intestines around the root of the mesentary

Front 483

What is the cause of volvulus in a young horse?

Back 483

change in feeding habit--shift to forage

-GI parasitism

Front 484

What are the clinical signs of SI volvulus?

Back 484

-abd pain
-reflux
-poor tissue perfusion
-decreased intestinal sounds
-distended SI on rectal

Front 485

How should a horse with SI volvulus be tx until sx?

Back 485

Aggressive fluid tx

Front 486

What is SI incarceration?

Back 486

A segment of the SI is entrapped through a rent in the mesentary, inguinal ring, gastro splenic ligament or epiploic foramen

Front 487

What can cause a mesenteric rent?

Back 487

Blunt abd trauma (trailer accident, kick)

Front 488

What is the gastropslenic ligament?

Back 488

Lesser omenrum that connects the stomach to the spleen

Front 489

What clinical might you see in a stallion with an inguinal hernia?

Back 489

-testicle on affected side with by enlarged, swollen, cold, painful
SI will be palpable entering the inguinal ring on rectal exam

Front 490

When do most cases of epiploic formane entrapment occur?

Back 490

Winter months
in horses 8+ year
cribbing is a factor

Front 491

How are SI incarcerations Tx?

Back 491

SX resection and anastomosis of strangulated section

Front 492

From where do pendunculated lipomas arise?

Back 492

Mesenteric adipose tissue

Front 493

As the lipoma stalk lengthens it can entrap the SI causing what type of obstruction?

Back 493

Mechanical

Front 494

Pedunculated lipomas occurs in horses > 9 and particularly of which breed?

Back 494

Arabs (and geldings)

Front 495

How do you distinguish feed impaction from pedunculated lipoma?

Back 495

--older horses rarely get feed impaction
-feed impactions generally do not lead to a cardiovascular parameters as with devitilized bowel

Front 496

Is diarrhea a primary sign of SI or LI dz?

Back 496

LI

Front 497

In horses, diarrhea is what type of condition?

Back 497

Emergency

Front 498

What is colitis?

Back 498

Active inflammation of the colon wall

Front 499

What is the cardinal sign of colitis?

Back 499

Diarrhea

Front 500

Which cell is the acute colitis effector cell?

Back 500

PMN- neutrophil

Front 501

What are the clinical signs of colic?

Back 501

-fever
-endotoxemia
-diarrhea
-peripheral edema
-colic pain
+/- reflux

Front 502

What can occur if diarrhea is severe or prolonged?

Back 502

Hypovolemia, shock

Front 503

What changes in bloodwork can indicate colitis?

Back 503

-neutropenia
-metabolic acidosis
-hyponatremia

Front 504

What might be seen on U/S in a horse with colitis?

Back 504

-swirling fluid within cecum/colon
-may also see dilated SI/stomach
-may see excess peritoneal fluid

Front 505

What would you expect the results to be of a peritoneal paracentesis for colitis?

Back 505

Normal fluid

Front 506

Which factors help in making a definitive dx of colitis?

Back 506

-fecal cultures
-bacterial toxins in feces
-PCR
-use of signalment/history
-use of season/time of year

Front 507

Regardless of the cause of colitis, how is it tx?

Back 507

Supportive care

Front 508

What are the first steps in colitis tx?

Back 508

-fluids to ocmbat dehydration, electrolyte loss and acidosis

-crystalloid/colloid to tx hypoproteinemia

Front 509

Why is hypertonic saline used with caution in colitis patients?

Back 509

-many are dehydrated and have volume depletion, hypertonic saline can lead to blindness and cerebral signs

Front 510

What are the components of anti-endotoxemia tx?

Back 510

-Nsaids
-equine plasma
-polymixin B (binds LPS)
-cryotherapy

Front 511

What additonal meds are given to tx colitis?

Back 511

-oral anti-diarrheal agents
-antimicrobials (beta lactam)
-TPN

Front 512

What are the potential complications of colitis?

Back 512

-endotoxemia (laminitis)
-thrombophlebitis
-coagulopathy
prolapsed rectum
-infarcted bowel

Front 513

Which is the most common serotype of Salmonella in horses?

Back 513

S typhimurium

Front 514

Which age of horse is more susceptible to Salmonella?

Back 514

younger
older
sick

Front 515

Transmission of Salmonella is by the fecal-oral route an causes what reactions?

Back 515

-intestinal wall inflammation
-hypersecretion
-ulceration
-protein and e-lyte loss

resulting inflammation impairs the mucosal barrier allowing luminal endotoxin to be absorbed

Front 516

What are the common clinical signs of salmonellosis?

Back 516

-fever
-diarrhea
-endotoxemia

Front 517

What clinicopathology results are seen with a Salmonella infection?

Back 517

-intense neutropenia with left shift
-toxic changes
-azotemia
-hypoproteinemia
-metabolic acidosis
-e-lyte loss

Front 518

How is a dx of Salmonellosis confirmed?

Back 518

-bacterial culture or PCR of feces, tissues or body fluid

Front 519

What is the most important tx for Salmonellosis?

Back 519

Fluid Tx

Front 520

What is the prognosis for Salmonella infection?

Back 520

variable- positive horses should be isolated while shedding the bacterium

Front 521

How does Clostridium overgrow and colonize the colonic mucosa?

Back 521

-stress
-immunosuppression
-changes in the normal flora from abx tx

Front 522

How is a dx of Clostridium infection confirmed?

Back 522

-fecal culture
-identicification of C difficle toxin A or B by Elisa or PCR

Front 523

How is Clostridum treated?

Back 523

-if infection is associated wtih antimicrobile tx, discontinue abx

-metronidazole is the first-line abx

mortality rate is high

Front 524

What is the causative agent of Potomac Horse fever?

Back 524

Neorickettsia risticii
has tropism for monocytes and enterocytes

Front 525

What is the intermediate host for N. risticii?

Back 525

A fluke that infests snails
snails are eaten by horses grazing pasures near freshwater in warm season

Front 526

What are the clinical signs of Potomac Horse Fever?

Back 526

can be sub clinical but signs same as Salmonella

Front 527

How is PHF dx?

Back 527

within 4-10 days of clinical signs, large rise in titers is see

Front 528

What is the tx of choice for PHF?

Back 528

Oxytetracycline

Front 529

What are the complications of PHF?

Back 529

-laminitis
-abortion

Front 530

What are cyathostomes?

Back 530

Small strongyles

Front 531

On the L3 larvae are ingested where do the migrate?

Back 531

Mucosa of the cecum and colon where they mature to L4

Front 532

What happens when the L4 excyst?

Back 532

The submucosal capsule ruptures, releasing the nematode larvae as well as excretory and secretory products that have accumulated over time

Front 533

What effect does this excystment have?

Back 533

Massive damage of the colonic mucosa

Front 534

What are the clinical signs of cyathostomiasis?

Back 534

-severe diarrhea
-rapid weight loss
-marked hypoproteinemia
-passage of larvae in the feces

Front 535

How is cyathostomiasis dx?

Back 535

Larvae may be seen in feces or fecal egg counts are high. Adult worms may be seen on the rectal sleeve of the examiner

Front 536

What is the tx for cyathostomiasis?

Back 536

-fenbendazole
-moxidectin

Front 537

Which abx should never be used in horses?

Back 537

Lincomycin

Front 538

Which abx are most associated with causing colitis in horses?

Back 538

-erythromycin
-ceftofur
-tetracycline
-ampicillin
-metronidazole
-neomycin
-trimethroprim sulfates

Front 539

Which insect carries the toxin cantharidin, a mucosal irritant?

Back 539

Blister beetles

Front 540

How do horses consume blister beetles?

Back 540

While eating alfalfa hay

Front 541

What are the clinical signs of cantharidin toxicosis?

Back 541

-ulceration, salivation of oral cavity
-colic
-diarrhes
-hematuria
-stranguria
-myocarditis

Front 542

Cantharidin can also cause what other condition resulting in signs of tetany and bizarre behavior

Back 542

Hypocalcemia

Front 543

How is cantharidin toxicosis dx?

Back 543

-suspected in hypocalcemia horses with oral, GI and urinary ulceration after consuming alfalfa hay

Front 544

What is the tx for cantharidin toxicosis

Back 544

-supportive care
-mineral oil my evacuate beetles from the intestinal tract

prognosis is poor with 50% mortality

Front 545

What is the cause of grain overload?

Back 545

Grazing on lush pasture
Feeding too much concentrate

to much CHO to cecum, lowers cecal pH

Front 546

What effect does decreased cecal pH have?

Back 546

-decreased fermentation
-cecal/colic dysmotility
-gas distention
-colic pain

Front 547

What is the tx for grain overload?

Back 547

-lavage, mineral oil, charcoal NGT
-anti-endotoxemia tx
-laminitis prophylaxis
-cecal trocar

Front 548

What is sand enteropathy?

Back 548

Horses on pasture with sandy soil consume sand as they graze or eat hay off the ground

Front 549

What are the clinical signs of sand enteropathy?

Back 549

-mild abd pain
-or severe pain if the right dorsal colon or transverse colon is acutely or completely obstructed
-horse mat stretch out or lie down
-may have diarrhea

Front 550

How is sand enteropathy dx?

Back 550

-fecal float in water for sand
-rads to see sand in ventral colon
-U/S guided bx of peritoneal fluids, disappearance of haustra with weight of sand

Front 551

What is the tx for sand enteropathy?

Back 551

-Metamucil in water vis stomach tube
-oral and IV fluids
-analgesics
-sx may be necessary to remove sand for right dorsal and transverse colons (via pelvic flexure enterotomy)

Front 552

Why do Nsaids cause mucosal ulceration?

Back 552

They suppress prostaglandin production which is necessary for bloodflow to the mucosa

Front 553

Nsaid induced colonic damage occurs when?

Back 553

Excessive doses in the face of water deprivation

Front 554

which segment of the colon is most sensitive to Nsaid toxicosis?

Back 554

Right dorsal colon

Front 555

With Nsaid toxicity, fibrosis may develop in the right colon leading to what condition?

Back 555

Stricture

Front 556

How do you dx Nsaid toxicosis?

Back 556

Clinical signs and a hx of recent nsaid use, elimination of other etiologies

Front 557

What U/S evidence can support the dx of nsaid toxicity?

Back 557

Thickening of the right dorsal colon wall

Front 558

What is the tx for nsaid toxicity?

Back 558

-Discontinue nsaids
-supportive care for colitis
-feed corn oil and psyllium to increase production of anti-inflammatory short chaon fatty acids

Front 559

What drugs should be used for pain management if Nsaids are to be avoided?

Back 559

-Butorphanol
-Lidocaine- cri

Front 560

Obstruction of the large intestinal lumen may occur due to what?

Back 560

-ingestion of coarse feed
-inadequate mastication
-insufficient water supply
-reduced intake of water

Front 561

What are the most common sites for impactions?

Back 561

Where luminal narrowing occurs
-pelvic flexure and left ventral colon
-junction between the right dorsal and transverse colon

Front 562

What are the clinical signs of large colon impaction?

Back 562

-mild intermittment colic
-minimal systemic deterioration
-heart rate may be slightly increased

Front 563

What is the tx for impaction?

Back 563

-oral and IV fluids
-mild analgesics
-laxatives
-overhydration
-isotonic solution should be used
-no feed until impaction is resolved..slow return to feed

Front 564

Cecal impaction can have the same causes as large colon impaction an what additional risk factors for cecal atony or motility dysfunction.

Back 564

-pts that have had general anesthesia
-tx w/ Nsaids

Front 565

What are the clinical findings in the case of cecal impaction?

Back 565

-severely painful, rupture is common

Front 566

Cecal impactions occur in horses of what age?

Back 566

8 years

Front 567

What is the tx for cecal impaction?

Back 567

Discuss sx correction with client due to rupture in 50% of cases

Front 568

Left dorsal displacment of the large colon is also referred to as what?

Back 568

Nephrosplenic entrapment of the large colon

Front 569

How does Nephrosplenic entrapment occur?

Back 569

-colonic distention
-spleen contracts in response to pain
-gas filled colon displaces dorsally
-spleen re-engorges and hooks colon

Front 570

What are the clinical signs of Nephrosplenic entrapment?

Back 570

-mod to severe abd pain
-heart rate varies
-pelvic flexure may be palpated over the ligament

Front 571

What are the treatment for Nephrosplenic entrapment?

Back 571

1. restrict feed intake and see if the condition corrects itself
2. tx w/ phenylephrine to induce splenic contraction
3. short-time IV anesthesia and roll horse
4. sx intervention

Front 572

What is an enterolith?

Back 572

Concretions composed of magensium, ammonium phosphate crystals around a nidus

Front 573

Geographically, where do enteroliths occur?

Back 573

Southwest US
CA
Fl
IN

Front 574

Which breeds are most affected by enterolith?

Back 574

Arabians/Arabian mix, adults

Front 575

What are the clinical signs of enterlithiasis?

Back 575

-recurring bouts of pain
-distention of the colon

Front 576

How can you dx an enterolith?

Back 576

Rads

Front 577

What is the tx for enteroliths?

Back 577

Sx: decompress the colon, remove enterolith

Front 578

Where is the enterotomy made to remove a transverse colon -right colon enterolith?

Back 578

At the pelvic flexure

Front 579

If an enterolith has a flat or polyhedral side, what should you do?

Back 579

Look for a second enterolith

Front 580

Strongylus vulgarus and S edentatus migrate to where in the horse?

Back 580

Cranial mesenteric artery

Front 581

What is the result of these larvae attaching to the arterial wall?

Back 581

Cause turbulent blood flow and creation of a thrombus that flows downstream and obstruct smaller vessels in the large intestine

Front 582

Arteritis of the cranial mesenteric artey leads to what condition?

Back 582

Thromboembolic colic

Front 583

Why are the cecum and colon at greater risk of ischemia from Thromboembolic colic?

Back 583

little or no collateral circulation

Front 584

What are the clinical signs of Thromboembolic colic?

Back 584

-mild to severe colic
-large intestine gas distention

Front 585

What is the tx for Thromboembolic colic?

Back 585

Sx resection of the ischemic bowel

Front 586

What is right dorsal displacement of the large colon?

Back 586

Pelvic flexure becomes displaced laterally around the base of the cecum and ends up near the diaphragm

Front 587

Why is this condition called right displacement?

Back 587

Colon is trapped to the right of the cecum

Front 588

How are horses with mild abdominal pain from right dorsal displacement treated?

Back 588

-remove feed
-fluid tx
-analgesia

Front 589

Where does a large colon volvulus occur?

Back 589

At the attachment of the colon to the cecum (near the cecocolic fold)

Front 590

Large colon volvulus is most often associated with what conditions?

Back 590

-impending or recent parturition
-a grass diet and/or highly fermentable feeds

Front 591

True or False....if the volvulus is < 270 degrees, there may be obstruction to the bowel lumen with tissue ischemia.

Back 591

True

Front 592

What is the hallmark clinical sign of large colon volvulus?

Back 592

When resulting in strangulation pain is severe and non-responsive to analgesics

Front 593

What other clinical signs are seen with large colon volvulus?

Back 593

-increased heart rate
-rapid deterioration of CV parameters
-distention of colon
-depression of ventilation and venous return
-reflux

Front 594

What time of year is small colon impaction more common?

Back 594

fall and winter

Front 595

What are the clinical signs of small colon impaction?

Back 595

-mild to moderate pain
-diarrhea
-distention
-endotoxemia

Front 596

What causes a small colon impaction?

Back 596

-dehydration of feces
-inspissated fibrous fecal material
-foreign body

Front 597

What exam should be performed on any horse presenting with diarrhea/colits?

Back 597

A rectal exam

Front 598

How is a small colon impaction treated?

Back 598

Medically: fluids and laxatives
Surgically: massage to break down the impaction or an enterotomy to remove the obstruction

Front 599

Where is an enterotomy performed in the case of a small colon impaction?

Back 599

pelvic flexure

Front 600

50% of horses that have sx for impaction have cultured positive for what organism?

Back 600

Salmonella

Front 601

What might be administered post op to help feed move through the small colon?

Back 601

Mineral oil

Front 602

What is a fecalith and where in the colon do they occur?

Back 602

Concentrations of feed material that form larger than normal fecal balls

Commonly obstruct the small colon, sometimes the large colon

Front 603

Which horse species is over represented in the occurrence of fecaliths? Why?

Back 603

Miniature horses and ponies

dietary indiscretion and breed associated dental problems

Front 604

What are the clinical signs of a fecalith?

Back 604

-mild to moderate colic
-usually no manure is passed once colic develops
-sever abdominal distention may be seen

Front 605

What is the tx for fecaliths?

Back 605

Sx removal of fecaliths- pelvic flexure enterotomy