Exam 1 Flashcards
What is the Most Likely Diagnosis?
A. Coagulopathy
B. Trauma
C. Ethmoid Hematoma
D. Guttural Pouch Mycosis
E. EIPH (Exercise Induced Pulmonary Hemmorhage)
Guttural Pouch Mycosis
*Guttural Pouch Mycosis- Usually Unilateral, Second Most common Clinical Sign is Dysphagia
*Not Coagulopathy- Horse would be having other Systemic Signs
Not EIPH- Lower Respiratory Tract Disease, would see Bilateral Bleeding and Associated with Exercise
Fluid Type that is Akin to Giving Free Water as Glucose is Rapidly Metabolized by Cells
D5W
*5% Dextrose Solution
*When you put D5W in an Animal, it acts as an Hypotonic Solution as if putting Free Water in the Animal, because Glucose is Rapidly Metabolized by Cells
Phase of Laminitis characterized by:
Post 72 Hours with Clinical Signs, and without Physical or Radiographical Evidence of Mechanical Disruption
Duration of Stage is Variabe- Days, Months, or Years (Typically 8-12 Weeks)
Hoof is Healing but still very Weakened and can still Structurally Fail
Subacute Phase
*Prolonged Clinical Signs Occur, but NO Mechanical Disruption
Yes
*Lines are NOT Parallel (Dorsum of Hoof Wall and Dorsum of P3)- Based on that, we have Rotation
*The Degree of the Angle = Degree of Rotation
*If we are taking an Exam and we have a Radiograph like this, except there are NO lines, the Easiest thing to do is pick up Scratch Paper and you can tell whether or no the lines are Parallel
Right Mainstem Bronchus
Treatment for Guttural Pouch Mycosis
Surgical Therapy - Obliterate Vessel (More Common)
Antifungal Administration- Takes 4-6 Weeks of Daily Infusions
*Most commonly only Treat with Surgical Therapy- Lesion will Resolve on its own. If we Obliterate the Vessel we do NOT Recommend also treating with Antifungals
If there is no History or Potential for Epistaxis in the animal, it can be Treated with Antifungals
When Administering Fluids Per Os, how many Liters/Hour are you able to Administer?
12-16 L/Hr
*Can Achieve 12-16 L/hr via Per Os Route
*We are Administering 6-8 Liters every 30 Minutes with this Route
Which of the Following is the Most Significant Factor in Deciding your Diagnosis?
A. Signalment
B. Location of Epistaxis
C. Intermittent Nature
D. Spontaneous Occurence
E. Degree of Epistaxis
F. Time Line
G. Other Signs
Signalment
Time Line
*Signalment for Ethmoid Hematoma- 10-12 yo Thoroughbred Male Horse
Time Line for Ethmoid Hematoma- Epistaxis is typically Mild, Spontaneous, Intermittent, and Unilateral. Ethmoid Hematomas are Often Present for many Months to Years
*B,C,D,and E do not Distinguish between Guttural Pouch Mycosis and Ethmoid Hematoma
Prognosis in Horses with Laminitis that are Exhibiting Mechanical Disruption and Sinking
Mechanical Disruption- Poor Prognosis
Sinking- Grave Progonsis
Disadvantages of which Fluid Administration Route:
Fluids tend to Track down within Abdomen causing Space Occupying Type Lesion in Abdomen resulting in Abdominal Discomfort
Vigilant need for Monitoring
Vigilance Regarding Sepsis- Can Result in Widespread Peritonitis
Intra-Peritoneal
*Acts as a Space occupying Mass and Creates Discomfort in Horses
Review Card
Maximum Volume Injected during Intramuscular Injections in the Semitendinosus/Semimembranosus of a Horse
15-20cc Maximum
If Horse presents with Chronic Sodium Disturbance with Clinical Signs, then ______correct to some Accepted Value (To the Limit of Compensation), then correct Slowely over Days to bring to Normal Value
Rapidly
*Chronic Changes Outside the Compensatory Range- Corrected Quickly to a Certain Range, and then Slowely back to Normal
Disadvantages of which Fluid Administration Route:
Virtually No Clinical Indication for its Use due to Limitation on Volume
Basically no Place for these Fluids in Horses- Especially Adults
Subcutanous
LPS Binds to LBP in Circulation and is shuttled to Target Cells, which are Pulmonary Intravascular Macrophages in the Lung. These Macrophages have _____ Receptors where the LBP will Bind. Then a Comformational Change will occur that will activate the _____ Receptor
CD 14- MD2
TLR-4 (Toll Like Receptor 4)
*Once the TLR-4 Receptor is Activated then Intracellular Signalling will occur and the production of Inflammatory Mediators- TNF alpha, IL6, IL1
Typical Presenting Complaint in Horses with Laminitis
Lameness/Reluctance to Move
Characteristics of which Route of Fluid Administration:
Could get Large Volumes at Fairly Rapid Rate
Easy Access without Need for any more Specific Equipment than Standard IV Administration
Alternative in Cases of Limited Venous Access
Intra-Peritoneal
Diagnostic Technique used in Horses with EIPH, because it is a Lower Airway Disease
Transtracheal Washes
BAL
*Neither of these Techniques are used in Cases of Guttural Pouch Mycosis or Ethmoid Hematomas- Upper Airway Diseases
Nares
Nasal Passage
Ethmoid
Nasopharynx
Guttural Pouch
Larynx
Trachea
*Horses don’t have a Pharynx
Two Stages of Shock Associated with Endotoxemia
Hyperdynamic State- Initial Stage
Hypodynamic State- Second Stage
Guttural Pouch
When Administering Bicarbonate Supplementation, Traditionally ____ of the Deficit is given over an Hour, then the Horse is Revaluated if Continued need to Re-Administer
Half
*Typically we don’t Replace the Total Bicarbonate Volume That has been Lost- While you are Administering first Half of Bicarbonate you are also using other techniques to Re-establish Circulation. When Circulation is Normalized, they should Self Correct the remaining Bicarb Deficit_. If we administer too much Bicarbonate we can put the animal into a Metabolic Alkalosis_
______ is used as a Preventive and Therapeutic to Neutralize Circulating Endotoxin
Endoserum
What is the Location of the Lesion?
A. Medial Compartment of Left GP
B. Lateral Compartment of Left GP
C. Medial Compartment of Right GP
D. Lateral Compartment of Right GP
Medial Compartment of Right GP
When doing Blood Gas Analysis, In order to Calculate how the Expected pH based on Change in PCO2
(Measured CO2 - Normal CO2)
For every 10mmHg Increase in CO2, get ____ Decrease in pH
0.05
*Ex. If PCO2 is 80, Calculate what the pH in the Horse should be:
80 - 40 = 40
Expected pH : (40/10) x 0.05 = 0.2
7.4 - 0.2 = 7.2
*A Horse with a PCO2 of 80, is expected to have a pH of 7.2
Most Likely Acid Base Distrubance that this Horse is Suffering From?
Metabolic Acidosis
*Typical Acid-Base Disturbance in the Horse is Metabolic Acidosis
Training Leads to all of the Following Muscle Changes EXCEPT?
A. More Type IIA Fibers
B. Volume of Mitochondria
C. Increase in Oxidative Enzymes
D. Increase in Glycogen Stores
E. More Type I Fibers
E. More Type I Fibers
*Training does NOT Result in more Type I fibers
Bloodwork:
Often changes in Sodium are Concomitant with Changes in Chloride. How can you Explain the Disconnect between Sodium (Low) and Chloride (Normal) Values?
Metabolic Acidosis
*Sodium is Low and Chloride is in the Middle Range- In most Situations Sodium and Chloride should be changing together. Often Changed in Sodium are Concomitant with Changes in Chloride.
If Bicarb starts Reducing, to Maintain Electroneutrality, the System is going to Retain Chloride
Ethmoid Turbinate
Training Improves Oxygen Delivery in all the Following ways EXCEPT?
A. Increase in Heart Mass
B. Increase in Lung Mass
C. Increase in Stroke Volume
D. Increase in Plasme Volume
E. Increase in Total RBC Volume
F. Increase Capillary Supply to the Muscles
B. Increase in Lung Mass
*Training Results in Little/No Adaptations in the Lung
True/False: Disease Process occuring in Only One Foot on a Horse, it is Most Likely NOT Laminitis
True
*Exception to this Rule: Horse that is significantly non-weight bearing on ONE Limb for an extended period of time. We worry about the Horse developing Laminitis in the Contralateral Limb (Weight Bearing Limb). Very specific scenario in which a horse may develop Laminitis in ONE Foot!
*Laminits is a systemic Disease- should see manifestation in AT LEAST the TWO Front Feet, or possibly all four feet
Treatment for Ethmoid Hematoma
Laser Surgical Ablation
Intralesional/IV Formalin- leads to Necrosis of Hematoma
*If Mass is extending into the Cribiform Plate, we do NOT want to Treat with Formalin
Most Important Technique for Evaluation of Coffin Bone Position with Respect to the Hoof thus Mechanical Disruption and Severity/Prognosis of Laminitis
Radiography
*Prognosis Determination is Closely linked to Changes and Progession Observed on Radiographic Evaluation
*Radiographs- we are looking for MECHANICAL DISRUPTION
Which of the Following Catheter Choices is best to achieve the Deficit Replacement (45L in One Hour)?
A. Two 14G Catheters
B. One 14G and one 12G Catheter
C. One 14G and one 10G Catheter
D. One 10G and one 12G Catheter
One 14G and one 12G Catheter
*Will Need to Place Two IV Catheters- None of the Catheters that we Routinely use will be able to Achieve the Volume that we need
Why not use Two 14G Catheters? Each 14G Catheter cannot provide more than 13L/Hr. Max that we would be able to administer in one Hour is 26L/Hr
*10G and 12G Catheter- More Thrombogenic. Two Larger Catheters with Higher Thrombogenicity. Using a 10G and 12G Increases Chances of creating Thrombosis in Jugular Veins
0.9% NaCl
*Endurance Horses have Metabolic Alkalosis. In Endurance Horses, the Number One Fluid that we will end up giving is NaCl
*These Endurance Horses are Loosing a lot of Chloride- Sweat is High in Chloride
When Endotoxin Enters Circulation, what Three things can Occur?
1. May bind to Circulating LPS Antibodies present
2. Removed Directly by RES in Liver
3. May bind to Circulating LBP (LPS Binding Protein)- Circulating Acute phase protein that we see in these animals
*With very small amounts of Endotoxin and these three Mechanisms in Play, no Endotoxin will get into the Central Circulation to have any major effect
Characteristics of which Fluid Aministration Route:
Most Common Method of Fluid Administration in Equine Patient
Easy Access
Unlimited Available Amount and Rate of Fluid Administration
Allows for Easy Change and Adjustment in Fluid Plan
Intravenous (IV)
Major Contraindication to Administering Fluids Per Os
Presence of Gastric Distension, Reflux and Ileus
*Do NOT Administer Fluids Per Os if the Horse is Refluxing
Possible Pathophysiology for Laminitis characterized by:
Displacement attributed to Shear Forces
Results in Movement of Hoof Wall up the Limb and Sole into the Ground
Damage/Disruption throughout Entire Foot- Release from Underlying Tissue and Lack of Support
Vertical Displacement (Sinking)
*Poorer Prognosis than Rotational Displacement
*P3 is being Driven Down in the Hoof- Sinking of the Hoof without Rotation
*Worse Case Scenario- Loss of Hoof
Flow Rate in L/hr for a 14G, 12G and 10G Catheter
14G = 13L/hr
12G = 27L/hr
10G = 36 L/hr
Signalment associated with which Cause of Epistaxis?
Incidence Related to INTENSITY of Exercise
40-100% of Racehorses have Evidence
80-100% Racing Thoroughbreds have Evidence
Exercise Induced Pulmonary Hemorrhage (EIPH)
*Related to Intensity of Exercise rather than Duration
Which Region of the Endotoxin is Antigenic?
Polysaccharide O-Region
*O Region is Highly Variable in Gram Negative Bacteria
Diagnoses based on this Hoof
Rotational Displacement (Laminitis)
*Dorsum of P3 is no Longer Parallel with Dorsum of Hoof Wall
*Inflammation, Hemorrhage and Clots are Present
Three Non Invasive Techniques for Local (Hoof) Support in Horses with Laminitis
Lily Pad- Rubber Insert that Fits over Heel
Pink Stryofoam Insulation
Roll Gauze Taped to Foot or Frog area
Phase of Laminitis Characterized by:
Mechanical Disruption/Collapse (Rotation or Sinking)
Occurs Irrespective of the Duration of the Process, can be as Fast as 24 Hours
Disruption involves Rotational Displacement and Vertical Displacement (Sinking)
Chronic Phase
*Clinical Signs with Mechanical Disruption
True/False: Most common Fluid Replacement used in Equines is LRS
True
*Almost Always using LRS as Fluid Replacement, except in very specific Situations
Possible Pathophysiology for Laminitis, Characterized by:
Gross Disconnect of Laminar Tissues
Major Forces Including: Vertical Load, Shear Forces, and Tensile Forces
Vertical Load playing Critical Role- Weight of Horse versus Size of Foot
Mechanical Disruption/Displacement
*Disconnection of Laminar Interdigitations- Loosing Support for P3 within the Hoof
Mechanical Disruption- Gross Disconnect of Laminar Tissues
Pattern of Recruitment of Muscle Fibers once Exercise Begins
In Horses under Stress, ______can give Overestimated Impression of Degree of Dehydration
Splenocontraction
*In Equine Patients under stress, Splenocontraction leads to High PCV. If you use PCV to make a Determination on Degree of Dehydration, you will OVERESTIMATE Dehydration
Two Antimicrobials that can be added to Systemic Circulation in Horses with Colonic Torsion, so that when you Un-Twist the Colon these Substances can Bind up Endotoxin and prevent severe Endotoxemia
Endoserum (Anti-Endotoxin Antibodies)
Polymyxin B (Sulfa Trimethoprim)
Where does the Highest amount of Endotoxin likely come from?
GIT- Cecum and Colon
*The GIT has the Highest Propensity for Developing Endotoxemia with Gastrointestinal Tract Disease- Horses have Naturally Occuring Endotoxin in their Gut
*Horses have tremendous amounts of endotoxin in their Intestinal Tract 24/7. Any time you have Cecum or Colon Disease- Very high Risk for developing Endotoxemia
Shock Dose Maximum in Horses
60-90 mL/kg/hr
Mostly Type ____ Muscle Fibers are Found within Equine Forelimbs
Type I
*Aerobic
Disadvantages of which type of Fluid Administration Route:
Technically More Difficult
Limited Rate of Administration by Size of Needle- Maximum Administered is 2L/Hour
Rate Sufficient in Foals, but Barely Compatible with Maintenance in Average Adult Horse
Intra-Osseous
*Classic Needles that you use for Intra-Osseous will acheive no more than 2L/Hour
Diagnosis based on these Endoscopy Results:
Visualization of Plaque on Internal Carotid Artery
Necrotic Tissue and Debris
Visualization of Blood from the Lesion/Pouch
Guttural Pouch Mycosis
True/False: Sinking, is Definitively Diagnosed via Radiograph
False
*Sinking is NOT Diagnosed via Radiograph. Sinking is a Clinical Diagnoses
True/False: Laminitis Most commonly affects the Two Hind Feet of the Horse
False
*Laminitis occurs in at least the Two FRONT Feet, or possibly all Four Feet. Will never have the Two Hind Feet involved without having the Two Front Feet involved
*Always the Two Front Limbs due to Weight Distribution- Horses carry more weight in their front limbs than their hind limbs
5-yr-old Thoroughbred Mare with 8 hr. History of Severe Colic
What is the Fluid Deficit in this Horse?
A. 7% Dehydrated: 31.5L
B. 10% Dehydrated: 45L
C. 14% Dehydrated: 63L
10% Dehydrated: 45L
Which of the Following is NOT a limitation of the Cardiovascular System in an Exercising Horse?
A. 20-50% Increase in Stroke Volume with No Further Increase
B. Extreme Heart Rate leads to Reduces Ventriular Filling Time
C. Hypoxemia Ensues at 65% VO2 max due to Diffusion Limitation
D. All of the Above are Limitations in Exercising Horse
D. All of the Above
Maximum Volume Injected during Intramuscular Injections in the Neck of a Horse
10-15cc Maximum
A Horse with Chronic Hyponatremia is Acutely Corrected by Administering a High Sodium Fluid, which Causes the Neuronal Cell to Loose water into the Interstitial Space, which Results in Cell _____ and Neurologic Dysfunction
Shrinkage
*Horses with Chronic Hyponatremia/Hypernatremia should be Corrected Slowely (Over 1 Week)
Recommended during Intravenous Injections in Horses that the Needle be pointed towards the ____
Heart
*Major Concern- Intra-Carotid Injections- Want to Minimize the Likely hood of Hiting the Carotid Artery rather than the Jugular Vein during Intravenous Injections- KNOW THIS
_*_If you use an 18 G 1 1/2 “ Needle Pointed towards the heart you are least likely to hit the Carotid Artery without knowing it
True
*Any Irritation anywhere within the Respiratory Tract is going to Elicit a Cough
Review Card: Energy System being used Through Duration of Exercise
As the Horse Begins Exercise- Phosphocreatine Pathway: Generates Tremendous Amount of ATP however only used in Initial Seconds of Exercise allowing Anaerobic pathway to “Come up to Speed”
Anaerobic Glycolysis- Peaks at 2 Minutes. Glucose Breakdown leading to Generation of Lactate and ATP. As Exercise Continues, the Anaerobic Glycolysis will Taper down as Aerobic Glycolysis is Gearing up
Aerobic Glycolysis and Fat Oxidation- Takes 35-40 Seconds to come to Maximal Function. Can be Sustained for Prolonged Periods
*All of these Systems are Engaged from the Beginning of Exercise- Only the Percentage of which System we are Using changes during Exercise