1. Food Animal Cardiology
M. S. Gill, DVM, MS

2. Initial examination Complete physical examination important
With special attention given to:
Mucous membrane color
Presence of jugular pulses
Edema

3. Jugular pulse

4. Jugular pulse & edema

5. Examination of the heart
Heart occupies ventral position in the thorax
Between the 3rd and 6th ribs
3/5’s of heart is on the left side

6. Examination of the heart
Auscultation
Heart sounds
S1, S2, S3, S4
Areas of auscultation of heart valves
Assessment of murmurs

7. Examination of the heart
S1 – beginning of ventricular systole (contracting myocardium and closure of AV valves)
S2 – closure of the semilunar valves
S3 – ventricular filling
S4 – atrial contraction
Normal sequence S4 – S1 – S2 – S3

8. Examination of the heart

9. Examination of the heart
Grading murmurs
Grade I
Grade II
Grade III
Grade IV
Grade V
Grade I is not clinically significant.
Grades IV and V are usually significant

10. Evaluation of the heart
Heart rate – should equal pulse
Tachycardia
Bradycardia
Rhythm
Most common arrhythmia in cattle is atrial fibrillation

11. Congenital cardiac defects
Early detection important
Expense
Genetic implications

12. Congenital cardiac defects
Ventricular septal defect*
Left to right shunt
Tetralogy of Fallot
Right to left shunt, cyanosis
Ectopia cordis
Patent foramen ovale
PDA

13. Vegetative endocarditis
Murmur
CHF may develop
Arcanobacter pyogenes or α-hemolytic strep in cattle, erysipelothrix or strep in swine
Lesions on valves are usually embolic in origin
Right AV valve usually affected

14. Vegetative endocarditis
Clinical signs
Poor doing animal
Exercise intolerance
CHF
Fluctuating fever
Clinical pathology
Severe leukocytosis
Diagnostics
Blood cultures
Echocardiography

15. Vegetative endocarditis
Large cauliflower-like or small verrucous lesions on heart valves, or,
Shrunken, scarred heart valves

16. Vegetative endocarditis

17. Vegetative endocarditis
Treatment
Cephalosporins/penicillin to calves with omphalophlebitis
Long term, broad spectrum antibiotics to cattle with vegetative endocarditis
Prognosis poor

18. Pericarditis Inflammation of the visceral and parietal pericardium
Most likely due to traumatic pericarditis – extension of traumatic reticuloperitonitis

19. Pericarditis Pathophysiology
Penetration of pericardium by metallic foreign body fibrinous exudate effusion with splashing sounds compromised heart function CHF

20. Pericarditis Clinical signs Pain Kyphosis Abduction of elbows
Shallow respirations
T – º F
Fluid splashing cardiac sounds or friction rubs or muffled heart sounds
CHF may develop late in the course

21. Pericarditis Most cows with pericarditis die in 1-3 weeks
Some develop chronic pericarditis
Leukocytosis – 16,000-30,000 WBC

22. Pericarditis Pericardiocentesis
Centesis performed at the 4th or 5th intercostal space at the level of the elbow on the left side

23. Pericarditis

24. Pericarditis Fibrin deposition Purulent exudate
Thickened pericardium / epicardium
Adhesions
Possible presence of metallic foreign body

25. Pericarditis Treatment Not very successful
Long term, broad spectrum antibiotics
5th or 6th rib resection (pericardiotomy) may be attempted but not very successful

26. Myocardial disease Myocarditis Cardiomyopathy
Inflammation of the myocardial wall (bacterial, viral, parasitic)
Cardiomyopathy
Dilated cardiomyopathy is the only form of clinical significance in large animals

27. Myocarditis Bacterial Viral Parasitic
Staph, Clostridium, 2º to bacteremia or septicemia, pericarditis, endocarditis
Viral
FMD
Parasitic
Toxoplasmosis, cysticercosis, sarcocystis

28. Myocarditis May be incidental finding at necropsy
Treat primary condition – i.e., cow with mastitis

29. Cardiomyopathy Toxicities: Deficiencies Monensin, lasalocid Gossypol
Cassia
Phalaris
Deficiencies
Vitamin E/Se (WMD or nutritional myodegeneration)
Copper deficiency

30. Cardiomyopathy Other causes Excess molybdenum High sulfates
Lymphosarcoma – neoplastic infiltration of myocardium

31. Cardiomyopathy Clinical signs – usually present with CHF
Treatment – poor prognosis – treat CHF

32. Cor pulmonale
Pulmonary hypertension, brisket disease, high altitude disease, or high mountain disease
Cor pulmonale reflects effect of lung dysfunction on heart, therefore, heart disease is secondary

33. Cor pulmonale Pathophysiology:
Pulmonary hypertension right heart hypertrophy, dilatation or failure
Underlying cause is hypoxic vasoconstriction caused by
High altitude dwelling (> 6,000 feet)
Pulmonary disease (bronchopneumonia or lungworms)

34. Cor pulmonale Clinical signs Treatment Signs of CHF
Remove from high altitude
Treat any primary lung disease
Reversible if treated early

35. Differentials for CHF Vegetative endocarditis Pericarditis Myocarditis
Cardiac lymphosarcoma
Dilated cardiomyopathy
Cor pulmonale or brisket disease

36. Electrocardiography Useful for diagnosis of arrhythmias Base-apex lead
Normal ECG:
Small positive P wave (may be notched)
QRS complex is either rS or QS
T is a positive monophasic or negative/positive biphasic wave

37. Normal cattle ECG

38. Atrial fibrillation Most common arrhythmia in cattle
Absence of P waves, presence of f waves, ventricular tachycardia with irregular rhythm
Atria remain distended & quiver due to numerous independent fronts of depolarization
CHF unlikely

39. Atrial fibrillation Organic – underlying heart disease
Functional - 2º to other abnormalities
GI disturbances, electrolyte abnormalities, pulmonary disease, brain disease

40. Atrial fibrillation Most cases are functional
May be paroxysmal or established
May convert to normal sinus rhythm spontaneously
Treatment involves correcting underlying condition – quinidine has been used in some cases that don’t correct on own

41. Atrial fibrillation

42. Atrial fibrillation

43. Sinus arrhythmia

44. Premature ventricular contractions
Etiology
Primary myocardial disease
Secondary to increased sympathetic tone, hypoxia, anemia, uremia, acidosis, sepsis, hypokalemia or various drugs
Rate normal but rhythm irregular
QRS complex of a PVC is premature, bizarre, prolonged & of larger amplitude
Unifocal or multifocal
Treat underlying condition or lidocaine

45. PVC – multifocal or multiform

46. PVC - unifocal

47. Pericarditis