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
Left
*Notice the Wall that the Ethmoid is Coming off of
In Radiographs of the Hoof, some will Mark the Distal most Aspect of the Pastern (Coronary Band area) to Mark the Horizontal Displacement of the Coffin Bone, namely _____
Sinking
How much is the Total Fluid Requirement for this Mare in the First Day?
68L
*Deficit: 0.05 x 400 = 20L
Maintenance: 60mL x 400 = 24,000mL = 24L
MUST DO TWICE MAINTENANCE- Overhydration
*For Horses with Intestinal Impaction, You need to use Overhydration to Increase Flow of Fluids to Intestinal Lumen
3 Markers used for Radiographs when Evaluating Laminitis
Dorsal Hoof Wall- Determination of Rotation of P3
Tip of Frog- Determine Specific Location of P3. Important with Respect to Placement of Heart Bar Shoes
Marker of Coronary Band- Evaluate Distal Displacement in the Hoof (Sinking)
Neither
*Parallel Alignment of P3 and Dorsal Hoof Wall = No Rotation
No Indentation at Coronary Band = No Sinking
*Diagnoses for Sinking is Classically CLINICAL, and not Radiographic
How will you Adminster Per Os Fluids to this Horse?
Nasogastric Tube
*How much Fluids can we pump into the Horse at one time? 6-8 Liters Every 30 Mintues
Gastric Capacity- 15 Liters
*Don’t want to put the full 15 Liters Capactiy of Fluid into the Stomach because extensive Distension of the GI Tract shuts down Motility
Most Common Acid-Base Disturbance in Equine Patients that is Characterized by Decreased HCO3 (Bicarb)
Metablolic Acidosis
*Leads to Hyperchloremic State
_*Even if we did not have a Blood Gas Analysis, we can Predict that the animal has a Metabolic Acidosis, based on a Disconnect between Sodium and Chlorid_e
Characteristics of Which Fluid Aministration Route?
Access to Free Water and/or Electrolyte Solution
Least Expensive
Lease Invasive with Less Complications
Especially Helpful in Large Intestinal Impactions- Ex. Colic
Oral/Per Os
Angiomatous Mass composed of Respiratory Epithelium and Fibous Tissue, which Progressively Enlarges as Variable Rates
Progressive Ethmoid Hematoma
*Grows Slowely- May be Present for Many Months to Years
Ethmoid Hematoma- Invades Locally and Creates Deformations Locally
*Resembles a Tumor but is NOT Neoplastic
What is the Top Differential Diagnosis in this Case?
EIPH (Exercise Induced Pulmonary Hemorrhage)
Cantor and Gallop Stride Frequency and Respiratory Rate are Coupled at ____ Ratio, thus limiting Respiratory Rate to a Maximum of 130/min
1:1
*Important Limitation- At Moderate to High Speeds of Movement, they are Linked into 1:1 Foot Fall to Respiratory Rate ratio. They cannot unlink this
*Maximum Achieve Respiratory Rate- 130 Breaths/min
True/False: If you are Distending the Jugular for Administration of the Needle for Intravenous Injection, make sure to keep the Vein Distended throughout the entire Injection
True
*Do NOT let go of the vein prior to injection- The Needle could Push through the Vein and become Perivascular (Intravenous Drug being injected into Muscle). Intravascular Drugs Injected Perivascular can lead to Necrosis (Fenylbutazone) or Laryngeal Paralysis if the drug hits the Recurrent Laryngeal Nerves- KNOW THIS
Which of the Following other Clinical Signs would you Expect to see in this Horse?
A. Unilateral Epistaxis
B. Respiratory Noise
C. Exercise Intolerance
D. Bilateral Epistaxis
E. No other Clinical Signs
Bilateral Epistaxis
Exercise Intolerance
If you take Hypertonic Saline and Perfuse it Directly into First Pass Circulation into the Heart, it is a _______, Creating a Decrease in Heart Function
Negative Ionotrope
*If you take Hypertonic Saline and Perfuse it Directly into First Pass into the Heart, it is a Negative Ionotrope- Creating a Decrease in Heart Function **KNOW THIS. However its Net Effect in the System, when administered into Vascular Circulation and its Diluted, it creates and Increase in Plasma Volume and all of those effects Supercede the Possible Negative Ionotropic Effect that is Specific to the Heart
*You DO NOT want Hypertonic Saline to go straight to the Heart
Number one Therapy, Most Notably in the Developmental Stage, for Laminitis
Cryotherapy (Ice Baths- Water and Ice)
*Very Important to do this in the Developmental Stage- Avoid development of Laminitis
*How long Does the Horse stay with Feet in Ice Water? Keep feet in Ice Water as long as the Horse is still Significantly ill from their Primary Disease and at risk for Developing Laminitis- At LEAST 24 Hours, and Possibly upwards of 48 Hours
Fungal Invasion of Tissue Resulting in Erosion of the Wall of the Arterial Structures of Guttural Pouch, most Notably the Internal Carotid Artery
Guttural Pouch Mycosis
*Plaque Like lesion in the Guttural Pouch
What Solution should you use in Deficit Replacement in this Horse?
A. 0.9% NaCl
B. 7.2% NaCl
C. D5W
D. LRS
E. 5% Sodium Bicarbonate
LRS
*Horse is Suffering from Metabolic Acidosis
0.9% NaCl- Acidifying Solution. Don’t want to use in a Horse with Metabolic Acidosis
*LRS behaves as an Alkalinizing Solution when put in the Horse
D5W = Dextrose 5% in Water
Chronic
*Determinant of Chronic Stage = Mechanical Disruption. Since Rotational Displacement (Mechanical Disruption) is Occuring in this Radiograph, it is considered Chronic
With Increased Intensity Exercise, Energy is being Derived via Oxidation of Carbohydrates, most Notably ______
Glycogen
*Further Increases in Intensity of Exercise cannot be met by Oxygen Supply, and Energy pathways change to Anaerobic
*During High Intensity Exercise- Glycogen is the Major Substrate Generating ATP
True
Clinical Signs associated with Which Cause of Epistaxis:
Epistaxis is typically Mild, Spontaneous, Intermittent and Unilateral
Blood-Tinged Mucoid to Mucupurulent Discharge
Malodorous Discharge
Ethmoid Hematoma
*Intermittent Recurrent Bleeds usually of a very small Volume
Which Stage of Shock is this Horse Displaying
Hyperdynamic State
*The Horse is going to be INJECTED- More Blood Flow to the Area
*Heart will be Racing and the Horse will be Shaking
*The Hyperdynamic State is Very short Lived. Usually will not see it Clinically
Possible Pathophysiology for Laminitis Characterized Below:
Displacement Attributed to Tensile Forces
Forces Originating from the Deep Digital Flexor (DDF)
Lack of Sufficient Dorsal Hoof Dermal-Epidermal Interface allows for Displacement (Leverage of Dorsal Hoof Wall)
Rotational Displacement
*Deep Digital Flexor = Tensile Forces
Rotational Displacement- Loss of Normal Alignment between the Dorsum of P3 and the Dorsum of the Hoof Wall- They should be Parallel. As soon as they loose the Parellelity, there is a Displacement of P3
*If Dorsal Laminae are not Attached, the Deep Digital Flexor is now only pulling P3, creating a Rotation
Best Area of the Neck for Administration of Intravenous Injections
Middle 3rd of the Neck
*Try not to be Low on the Neck for IV Injections due to Proximity of the Carotid Artery and Jugular Vein. As you Move up the Neck the Artery and Vein Separate
Which Region of the Endotoxin is the culprit of the Clinical Significance and Signs/Problems we have with Endotoxemia
Lipid A Region
*The Lipid A component is not very Antigenic
What is your Final Diagnosis?
Guttural Pouch Mycosis
Ozena, a Foul Odor, is usually Associated with Which Cause of Epistaxis?
Ethmoid Hematoma
*Malodorous Discharge is often Seen with Ethmoid Hematoma
What is the Degree of Dehydration?
A. None
B. 5%
C. 8%
D. 11%
E. 15%
8%
*Animal is Somewhat Dehydrated, but Not Severe
*Tacky Mucous Membranes, CRT = 2.5 (Prolonged CRT)
Recommended Needle Size for Intravenous Injections in Horses
18 G 1 1/2 “ Needle
*Needle should be no LESS than 19 G 1 1/2 “ Needle
*Always Seed the Needle to the hub in parallel with the Vessel
The Gelding Defecates 2 Liters every 2 Hours. How many Liters of Fluid would this Horse be Recieving a Day?
94L
*Deficit (8% Dehydrated): 0.08 x 500 = 40L
*Maintenance: 60mg/kg/day x 500 = 30L
Ongoing Losses: 2L x 12 = 24 L
40L + 30L + 24 L = 94L/24 Hours
*Of which First 40L Ideally given in First Hour
Based on the PCO2 in this Horse, what is the Expected pH?
7.13
94.6 - 40 = 55
(55/10) x 0.05 = 0.27
Expected pH: 7.4 - 0.27 = 7.13
*Side Note- If the Patient had an Alkalosis, the 0.27 would be Added to 7.4 to predict the pH
True
Medial
*This is an Image of the Right Gutteral Pouch
*Lateral Compartment is Smaller than Medial Compartment. They are Divided by Stylohyoid Bone
*Large Vagus Nerves are Found in the Medial Pouch!
Normally the Stylohyoid Bone is Bowing towards the Lateral Compartment
Horse Presents with Profuse, Acute, Bilateral Epistaxis
Trauma
*Nasogastric Intubation
9-yr Old Standard Breed Mare
History: Colic (Mid Abdominal Pain for 12 Hours)
How would you Administer these Fluids?
A. SQ
B. IV
C. Per Os
D. Per Rectum
E. Intraperitoneal
F. Intra Cecal
Per Os
Per Os- Especially Helpful in Large Intestinal Impactions - This Horse has Firm Ingesta in the Intestinal Tract
*We want to Liquify that Content/Firm Ingesta to allow the Horse to pass it
Most Common Surgical Treatment for Guttural Pouch Mycosis
Transarterial Coils
*Most Advocated Treatment for GPM
What is the Degree of Dehydration?
A. None
B. 5%
C. 8%
D. 11%
E. 15%
None
*If the Horse had been at least 5% Dehydrated there would have been Slightly Tacky Membranes
*High Heart Rate- Normal in Foals/Fillys
Classic Gait seen in Horses with Laminitis
Walking on Eggshells
*Gingerly Walking and Picking up Limbs Quickly
Epistaxis
PEH = Progressive Ethmoid Hematoma
Bilateral Lesion
Large Volume Bleeding
Unilateral Lesion Invading to Opposite Side
*No Coagulation associated with Ethmoid Hematoma
True/False: Adult Horses and Foals with Endotoxemia should not be given “Cidal” Antimicrobials because they will Severely Increase the Endotoxemia
False
*Foals with Endotoxemia should not be given “Cidal” Antimicrobials because they can worsen the Endotoxemia
*In Adult Horses there is NO Evidence that giving “Cidal” Antimicrobials have any significant impact on the severity of Endotoxemia
False
Unilateral Nasal Discharge- Only Upper Airway
Signalment for which Epistaxis Disease:
Most Often Older than 8 Years (10-12) of Age
Thoroughbred, Warmbloods
Male Stallions
Ethmoid Hematoma
Treatment for Horses with EIPH
Lasix (Furosemide)- Most widely Used and Recommended
*Lasix- Decreases Pulmonary Capillary Pressure during Exercise
Two Circumstances in Horses where we will use the Overhydration Fluid Technique
Liquefaction of Respiratory Secretions
Intestinal Impactions
*Respiratory Disease- Overhydrate in order to Loosen up the Junk that is caught in their Airways
The Target Cell for the Activation of Endotoxemia originates from the Pulmonary Intravascular _____
Macrophage
*In Horses, the Lung has the Greatest Amount of Intravascular Macrophages. Pulmonary Intravascular Macrophage- Target Cell for Endotoxemia
Distal Trachea
Classic Stance for Horses with Laminitis in Its Two Front Feet
Front Feet are Somewhat out Forward
*Preferential Loading on the Heel Region of Hoof
*Common in Horses with Laminitis in the Front Limbs- Classically sitting on their Heels
The Polysaccharide Region of Endotoxin is ______, While the Lipid A Region is ______
Hydrophilic- Polysaccharide
Hydrophobic- Lipid A
*Lipid A Region (Hydrophobic) in a circulation that is water based- Makes Micelles. If you have a lot of Endotoxin in circulation, the unbound Endotoxin will find eachother and make Micelles
No
*Nasopharynx is Lumpy/Bumpy- Inflammation of Nasalpharnyx
Larynx- Missing Visualization of Epiglottis due to Inflammation
Energy System used in Initial Seconds of Exercise that Generates a Tremendous amount of ATP however is only Sustained for a few Seconds
Phosphocreatine Pathway (PCr)
Left
On Left of Image
Branch off to Lower Lung Directly after Bifurcation
*In Image you can see Accessory Bronchi (White Oval), which Branches Off on the Right Side of the Trachea after Bifurcation of Trachea
Review Card
*Horses with Stress and Endotoxemia will have a Total WBC Count within Normal Limits with a Lymphopenia
In Horses with Laminitis, Pain is Evaluated by Hoof Testers. Pain is usually detected at the ____
Toe
*Hoof Testers- Identify Pain within the Foot
*Laminitis- Responsive and Painful at the Toe
Phase of Laminitis characterized by:
First Identifiable Clinical Signs
This Phase ends after the Development of Either:
Passing of 72 Hours without Physical or Radiographic Evidence of Mechanical Disruption
or
Development of Mechanical Digital Collapse
Acute Phase
*Clinical Signs Occur, but NO Mechanical Disruption
Clinical Signs Seen- Weight Shifting, Heat in their Feet, Increased Digital Pulses, Abnormal Gait/Stance, Positive on the Toe with Hoof Testers
Cationic Polypeptide Antibiotic that exerts its effect by Binding with Lipid A, thus preventing its interaction with Inflammatory Cells that is used to Neutralize Circulating Endotoxin
Polymixin B
Early on in Shock, there will be an overwhelming ____ State. As Shock Progresses, there is a tendency towards an overwhelming _____ State
Vasoconstrictive- Hyperdynamic
Vasodilatory- Hypodynamic
Horses with Laminitis will have Increased Digital _____
Pulses
*Strong, Bounding Digital Pulses
*Digital Pulses are Not Detectable in Normal Horses
Treatment for Rotational Displacement leading to Laminitis
Cut Deep Digital Flexor
*Stops the Rotation from Perpetuating
Distal Nasopharynx
During Low Intensity Exercise, the Horse is Exercising Largely _____, while the Vast majority of Energy is being Derived by Beta Oxidation of Free Fatty Acids
Aerobically
*During Low Intensity Exercise- Fats are major Substrate Generating ATP
Opening to Guttural Pouch
*R = Right Side
*In this Image we are in the middle of the Nasopharynx
True/False: If Bleeding from an Ethmoid Hematoma is High Volume, the Bleeding can be Bilateral
True
*Ethmoid Hematoma can lead to Bilateral Bleeding in 15-20% of Cases due to presence of 2 Lesions, Extension of One Lesion into the Other Side, or Due to High Volume of Bleeding
In Horses, _____ Increases Oxygen Carrying Capacity by Increasing Circulating Red Cell Volume (PCV)
Splenocontraction
Epistaxis Resulting from Disruption of Pulmonary Capillaries as a Consequence of High Cardiac Output required during Intense Exercise
EIPH
The _____ the Diameter of the Catheter, the more Thrombogenic
Larger
*Ex. 10G Catheter is MORE Likely to Cause Thrombosis than a 14G Catheter
Horses with Laminitis have Swelling, Inflammation (Heat) and Edema of the ______
Coronary Band
Classic Stance in Horses with Laminitis in All Four Hoofs
Inverted Tripod
*Trying to Gain Equal Weight Distribution
While Performing Radiographs of the Hoof, we Mark the Dorsal Surface of the Hoof Wall (Coin, Metal Strip of Wire, ect.) to Evaluate ______
Rotation
The Gelding Defecates 2 Liters every 2 Hours. If you have Fulfilled the Deficit upon Intial Treatment, what is the Remainder of the Volume of Fluids he needs to Receive that First Day?
A. 24L
B. 30L
C. 40L
D. 54L
E. 70L
F. 94L
54L
*Maintenance: 60 ml/kg/day
60ml/kg x 500kg = 30L
*Ongoing Losses: Diarrhea
2L x 12 = 24L
30L + 24L = 54L
Fluid Therapy = D + O + M
Deficits have already been given in this Patient
5-yr-old Thoroughbred Mare with 8 hr. History of Severe Colic
How would you Administer These Fluids in this Horse?
IV
*Animal is Refluxing- Cannot give Fluids Per Os
In a Horse with Acute Hypernatremia/Hyponatremia, you correct this as ____ as Possible using D5W
As FAST as Possible
*Acute Hypernatremia- Give D5W, because it is equivalent to Free Water and will Dilute Sodium
*In Horses with Acute Hypernatremia/Hyponatremia, we want to get the Horse back to Normal as FAST as possible
A Goal of Treatment for Endotoxemia involves Inhibition of Synthesis and Effects of Endotoxin-Induced Mediators. The Most Accepted/used Modality is via the Administration of NSAIDs, notably ________
Flunixin Meglumine
*#1 Drug of choice used in these Patients. Used in all cases where the Horse is believed to be Endotoxemic
*Substantial Evidence that Flunixin reduces the Effects of the Endotoxin and the Mediators Produced
Phase of Laminitis characterized by:
Prior to the Development of Clinical Signs of Laminitis
Developmental
*No Clinical Signs
Clinical Signs associated with which Cause of Epistaxis:
Poor Performance- Quitting
Epistaxis (1-10% of Cases)
Coughing
Increased Swallowing Efforts while Racing
Gurgling/Choking
Exercise Induced Pulmonary Hemorrhage
*Many Cases may have No Clinical Signs
*EIPH is the Number One Cause of Epistaxis in the Exercising Horse, but the vast majority of EIPH horses are not Bleeding through their Nares. Most Horses are only Bleeding in their Trachea
Review Card
Which Stage of Shock is this Horse Displaying
Hypodynamic State
*Congested- Circulation is Stagnating- Blue Color
*Hypothermic- Caused by Peripheral Vasoconstriction. In Peripheral Limbs there is Vasoconstriction leading to Cold Extremeties. Although Overall, the Horse is experiencing Net Vasodilation in the Hypodynamic State
Guttural Pouch Mycosis Predisposition for Location on Internal Carotid Artery is though to be Related to High ____ at these Locations
Oxygen Tension
Adjustable Shoe that Provides Support for Horses with Laminitis
Adjustable Heart Bar
Horses with _____ will have Increases in Pulses Equally of the Lateral and Medial Palmar Digital Arteries of at least the Two Front Limbs or all Four Limbs
Laminitis
*If you have an Increase in the Medial and Lateral Palmar Digital Arteries in One Foot- NOT likely Laminitis
In Horses with EIPH that are a Grade 1 or Grade 2 you would not expect to see ______
Exercise Intolerance
4 yr old Standardbred Racing Mare with Mild Bilateral Epistaxis. You perform and Endoscopy. What is your Diagnosis?
EIPH
*Pool of Blood in the Trachea
What Grade would you Classify this Horse? Grade 3
Categorize this Disease
A. LRT Infectious
B. LRT Non-Infectious
C. URT Infectious
D. URT Non-Infectious
URT Non-Infectious
*Not Lower Respiratory because there is Unilateral Discharge
Unilateral Discharge- Upper Respiratory ONLY
Non Infectious- No Fever, Non Purulent Discharge
The Disconnect in a Rotational Displacement, is the ____ Laminae
Dorsal
*If Dorsal Laminae are not Attached, the Deep Digital Flexor is now only pulling P3, creating a Rotation
*If you want to Stop the Rotation what would you do? Cut Deep Digital Flexor (DDF)
Name Two Anti Inflammatory and Analgesic Drugs that are an Essential Component to the Treatment of Laminitis
Antiinflammatories- Flunixin and Fenylbutazone
Analgesics- Fenylbutazone (Systemic NSAID)
*Analgesics- Very Important. Need to Control the Pain in their Feet
Evaluation of Coronary Band for _____
Sinking
*See if you can get your Thumbnail under the Coronary Band = Sinking
5-yr-old Thoroughbred Mare with 8 hr. History of Severe Colic
Horse Refluxes 20 Liters Twice and then 1.5 Liters every Two Hours for 12 Hours. If Deficit is Replaced in First Hour, How much Volume Remains to be Administered that First Day?
76L
Fluids = D + M + O
*Deficit has Already Been Administered
Maintenance: 60mL x 450 = 27L
Ongoing Losses: (20L x 2) + (1.5L x 6) = 49L
27 + 49 = 76L
7.2
80 - 40 = 40
Expected pH : (40/10) x 0.05 = 0.2
7.4 - 0.2 = 7.2
Goal of Intervention during the Developmental Stage of Laminitis
Prevent Development
Ex. Icing the Feet- Icebath
*Rather than Treat and Affected Patient
Disadvantages of which Route of Fluid Administration?
Danger of Compromise to Vein- Ex. Thrombosis
Introduction of Organisms- Sepsis
Requires Sterility of Both Placement and Fluids used
Expensive
Requires Monitoring, Frequent Evalutions of Fluids, Catheters and Catheter Changes
Intravenous
Due to Proximity of Structures, Occasionally Horners Syndrome, Laryngeal Hemiplegia and other Neuropathies can be seen with which Cause of Epistaxis?
Guttural Pouch Mycosis
*Some horses with Guttural Pouch Mycosis my Present Solely with Neuro Signs Alone
9-yr Old Standard Breed Mare
History: Colic (Mid Abdominal Pain for 12 Hours)
What is the Degree of Dehydration?
5%
*Tacky Membranes, but other Parameters are not abnormal
True/False: Insulin Resistance with Hyperinsulinemia is a Key Determinant in Susceptibility to Laminitis in Horses and Ponies
True
*Insulin Resistance Horses and Ponies are MORE LIKELY to develop Laminitis
True/False: This is what we expect to see on the CBC of a Horse with Endotoxemia
True
*Normal Total WBC Count should be: 6,000-12,000
Normal Segmented Neutrophils- 4,000-10,000
Normal Bands Neutrophils- 0-100
Normal Lymphocytes- 1000-6,000
*This Horse has a Significant Lymphopenia. Total WBC Count and Segmented Neutrophils are on the Low Edge of Normal. Stress and Viral Disease are the two major causes of Lymphopenia in Horses. Lymphopenia Caused by Stress would also show a Neutrophilia. What we are seeing here is a CBC in a horse that has Concurrent Stress and Endotoxemia. Stress Increases Neutrophils while Endotoxemia Decreases them, leading to a Neutrophil Count within Normal Limits
LPS Binding Protein that is an acute phase protein which acts as a Shuttle Protein bringing LPS from aggregates to responding cells
LBP
*Shuttle Protein- the Big Issues that we see with respect to Endotoxemia, have to do with LPS bound to LBP going to that target cell in the Lung
_*_If you can reduce the LPS being shuttled to the target cell then you hopefully will reduce the negative effects associated with Endotoxemia
