Final Exam--Equine & Food Animal

Question 1

Though all 4 heart sounds are considered normal to hear in the horse, which gallop sound is more common?

Answer 1

S4 (atrial contraction)

Question 2

Contrast pathologic and physiologic(innocent) murmurs

Answer 2

Pathologic–backward flow through a valve that should be CLOSED

Physiologic–vibration of forward flow through a valve that should be open

Question 3

How should physiologic murmurs auscultate?

Answer 3

short and quiet (no greater than grade 3/6)

Question 4

The most common NON-PATHOLOGIC arrhythmia in horses?

Answer 4

second degree AV block–type 1

Question 5

Describe the rhythm of second degree AV block (type 1)

Answer 5

regularly irregular (3 beats, pause, 3 beats, pause)

Question 6

second degree AV block can be induced by?

Answer 6

sedatives (alpha-2 agonists)

Question 7

What lead to we run horse ECGs on and why?

Answer 7

Lead 1–extensive purkinje network

Question 8

Two most common reasons for a systolic murmur with PMI on left side (adult horses). Where does each localize?

Answer 8

Mitral regurgitation (MI)–APEX

Physiologic flow murmur–BASE

Question 9

If you hear a murmur on the left but it’s loudest on the RIGHT, what is it most likely due to?

Answer 9

Relative pulmonic stenosis from VSD

Question 10

Two most common reasons for systolic murmurs with PMI on the RIGHT

Answer 10

ventricular septal defect (VSD)

tricuspid regurgitation

Question 11

Two common reasons for DIASTOLIC murmurs on the LEFT side in adult horses. Where do they localize?

Answer 11

Aortic regurgitation (base)

diastolic flow murmur (apex)

Question 12

When it comes to VSD, you want the lesion to be _____ & have ______ _____

Answer 12

small; high velocity (both are GOOD prognostic factors)

Question 13

4 defects associated with tetralogy of fallot

Answer 13

large VSD
over-riding(reaching) aorta
true stenosis of pulmonary valve
RV hypertrophy

Question 14

PMI with tetralogy of fallot is on which side and why?

Answer 14

LEFT side (due to right to left shunting of blood…caused by the stenosed pulmonic valve)

Question 15

The most common etiology of aortic insufficiency?

Answer 15

Degenerative change (horses > 10yr)

Question 16

A waterhammer (bounding) pulse is indicative of?

Answer 16

significant volume overload (due to aortic regurg)

Question 17

Which valvular disease is most common in athletic/trained horses?

Answer 17

Tricuspid regurgitation

Question 18

Most common PATHOLOGIC arrhythmia of horses?

Answer 18

atrial fibrillation

Question 19

Describe the rhythm that you hear with atrial fibrillation

Answer 19

irregularly, irregular (pulses are also irregular)

Question 20

3 factors that can affect refractory periods in the horse?

Answer 20

1) high vagal tone
2) myocardial pathology
3) electrolytes disturbances (low K)

Question 21

Most common complaint of owner’s in horses with Afib?

Answer 21

exercise intolerance

Question 22

A class 1a antiarrythmic used for conversion of Afib?

Answer 22

Quinidine sulfate

vagolytic

Question 23

When should conversion for afib not be attempted?

Answer 23

When it is due to underlying cardiac disease/heart failure

Question 24

Concerning ventricular tachycardia (VPCs)

1) HR when Tx should be considered
2) HR that indicates an emergency

Answer 24

1) >60bpm

2) >120bpm

Question 25

How does Magnesium function in treatment of VPCs?

Answer 25

works as a Ca antagonist to slow conduction

Question 26

Most common cause of 3rd degree AV block in horses?

Answer 26

scarring/fibrosis of AV node

Question 27

What 3 electrolytes can impact myocyte contractility?

Answer 27

Ca, K, Mg

Question 28

3 main causes of myocardial disease

Answer 28

Inflammation (myocarditis) Degeneration/necrosis Electrolyte abnormalities

Question 29

How do ionophores cause myocyte degeneration?

Answer 29

bypass Na/Ca exchanger and bring Na into the cell, causing less Ca to be transported out Ca stimulates more Ca leads from SER, causing Ca to build up in the cell and become toxic

Question 30

Most common causes of CHF in horses?

Answer 30

Acute & chronic valvular disease

Question 31

Why is alveolar edema uncommon in horses with CHF?

Answer 31

their lungs can handle a large amount of venous pressure before fluid enters the alveoli

Question 32

Right-heart failure in horses is most commonly associated with?

Answer 32

Chronic left-sided disease/failure that lead to pulmonary hypertension

Question 33

3 drugs that can be used for management of CHF in horses?

Answer 33

Digoxin Pimobendan Furosemide

Question 34

Location of action for: 1) digoxin 2) Furosemide

Answer 34

1) Blocks Na/K ATPase | 2) inhibits Na/K/2Cl symporter in thick ascending LoH

Question 35

the 3 categories of vascular disease in horses

Answer 35

Thrombosis Rupture Vasculitis

Question 36

This disease of horses often occurs secondary to infection (most commonly with Step. equi)

Answer 36

Equine Purpura hemorrhagica

Question 37

How does EPH cause vasculitis?

Answer 37

deposition of immune complexes in vessel (venule) walls *Type III hypersensitivity*

Question 38

Give 3 causes for: 1) increased heart sounds 2) decreased heart sounds

Answer 38

Increased: 1) hypomagnesemia 2) cranioventral bronchopneumonia 3) thin animal Decreased: 1) displacement of heart by a mass 2) change in pericardial or pleural space 3) hypocalcemia

Question 39

Most common pathologic arrhythmia in cattle?

Answer 39

atrial fibrillation

Question 40

In cattle, Afib commonly occurs secondary to?

Answer 40

an underlying GI disease (i.e. LDA, RDA)

Question 41

Most common cause of pathologic murmurs in adult cattle?

Answer 41

valvular disease--Tricuspid insufficiency

Question 42

Where to puncture for pericardiocentesis?

Answer 42

Left side, 5th ICS

Question 43

When the heart is located outside the pleural cavity, it's called? Where is it most commonly located instead?

Answer 43

Ectopia cordis cervical region

Question 44

The most common atrial septal defect?

Answer 44

patent foramen ovale

Question 45

Most common valvular defect in swine?

Answer 45

Dysplasia of tricuspid valve

Question 46

What CBC/Chem findings would support a diagnosis of hardware disease?

Answer 46

neutrophilic leukocytosis or leukopenia with a left shift high fibrin, high globulins

Question 47

Most common cause of acquired murmurs in cattle?

Answer 47

endocarditis (most common cause of valvular disease)

Question 48

Most common bacteria associated with endocarditis in each spp. and preferred valve site 1) cattle 2) swine

Answer 48

1) T. pyogenes; tricuspid valve (listen on R side) | 2) S. suis; mitral valve (listen @ L apex)

Question 49

The most common form of cardiomyopathy in livestock?

Answer 49

dilated cardiomyopathy

Question 50

Which disease is associated with cattle kept at high altitudes?

Answer 50

Brisket disease (high altitude disease, mountain sickness)

Question 51

List species from most to least susceptible to ionophore toxicity (list sheep, horses, and cattle)

Answer 51

horses (most) sheep cattle (least)

Question 52

Ionophore muscle preference in: 1) horses 2) cattle 3) sheep & swine

Answer 52

1) prefers cardiac 2) cardiac and skeletal equally affected 3) mainly impacts skeletal muscle

Question 53

Two factors that increase sensitivity to gossypol

Answer 53

1) being monogastric (i.e. swine) | 2) stress (lowers tolerance)

Question 54

Which part of Senna spp. are considered most hazardous? And which spp. most often develops clinical signs?

Answer 54

seeds (put all parts are toxic) Cattle

Question 55

Grayanotoxin is associated with?

Answer 55

Rhododendron spp. (azaleas)

Question 56

primary signs of Grayantoxin ingestion in goats?

Answer 56

Vomiting!!! | bradycardia

Question 57

Primary agent associated with bacterial myocarditis in cattle?

Answer 57

Histophilus somni *myocarditis develops after a respiratory event (BRDC)*

Question 58

2 pathogens associated with myocarditis in swine?

Answer 58

``` Strep. suis Erysipelothrix rhusiopathiae (chronic form) ```

Question 59

Which type of cattle are predisposed to caudal vena cava thrombosis?

Answer 59

feedlot/adult cattle that are on high grain diets

Question 60

A tickborne, rickettsial foreign animal disease associated with vasculitis in cattle

Answer 60

heartwater

Question 61

Predilection sites for lymphosarcoma

Answer 61

HAULS Heart (RA), abomasum, uterus, lymph nodes, spinal cord

Question 62

4 mechanisms of heat dissipation

Answer 62

radiation conduction convection evaporation** **only one that does NOT require temperature gradient

Question 63

The gene involved with porcine stress syndrome

Answer 63

halothane gene

Question 64

Describe the pathogenesis of porcine stress syndrome

Answer 64

(aka malignant hyperthermia) A trigger (stressor) causes a rise in intracellular Ca, leading to muscle contraction