This presentation is about the important aspect of cardiovascular system of equine in course equine veterinary medicine.

1. Submittted by:
SUMREEN KOUR
MVSc Scholar

2.  Disease of CVS are rare in horses
as compared to other species.
 Evaluation of CVS is an essential
part of physical examination.
 Location:2nd ICS to 6th rib.

3.  Signalment.
 History taking.
 Inspection.
 Palpation.
 Percussion.
 Auscultation.
 Diagnostic aids-electrocardiography.
-echocardiography.
-exercise testing.

4.  Helps to determine likelihood of certain cardiac
problems.
 Important aspect is age.
 Sex-aortic ring rupture in older horses.
Young horses(<3 years old):congenital cardiac problem.
Older horses(> 3years old):valvular/conduction disturbance

5.  Information about stable condition.
 General environment
 Present & past performance
 Previous disease
 Vaccination
 Deworming history
 Appetite
 Water consumption
 Urination & defecation.

6.  Initialy includes :general attitude
movement in stall.
 Prominent juglar pulse with distended vein alerts the
clinician.
VENOUS CIRCULATION:
Evalution is difficult because of low pressure.
Juglar pulse is seen –reflects right atrial(4mm Hg) & thoracic pressure
changes.
If head is lowered/ if right atrial pressure is increased
Juglar distention –Right sided CHF.

7. MUCOUS MEMBRANE COLOUR:
Give guide to approximate tissue oxidation & perfusion of capillary bed to
assessed area.
NORMAL: pale pink(mouth & eye)
pink (nasal septum)
Bluish/cyanotic (hypoxygenation)
dark red(deydration & endotoxemia)
CAPILLARY REFIL TIME:
Pressing index finger on MM on gum & above corner incisor tooth.
Blanching of MM after which blood will refill-1-2sec.
Prolonged CRT-decreased peripheral perfusion.

8.  Facial artery
 Transverse facial artery near lateral canthus of
eye.
PERIPHERAL PULSE:
Pulse character depends on:vessel size
distance away frm heart.
difference between systolic & diastolic
pressures.
Increased digital pulse: laminitis.
Exaggerated pulse:aortic insufficiency
Decreased pulse:shock & hypovolemia

9.  Its important to palpate all four legs,ventral
chest & abdomen for any swelling signs.
 Palpation of apex beat –indication of heart in
thorax.
 Apex beat felt on left ventral chest wall about
10cm dorsal to sternum in5-6 ICS.
 If thrill detected on cardiac palpation-severe
flow disorder.

10.  INITIAL AUSCULTATION:
 Examine with stethoscope.
 Examination starts over area of apex
beat,caudal to triceps muscle & about area
10cm ventral to level of point of shoulder.
 25-40 beats/min.

11. FIRST HEART SOUND:
Generated by closure of left(mitral) & right (tricuspid) artrioventricular
valves.
Maximum audibility of mitral valve –on left 5th ICS.
Maximum audibility of tricuspid valve –on right side at 4th ICS.
SECOND HEART SOUND:
Sound generated by closure of aortic & pulmonary valve & is synchronous
with end of systole & begining of of cardiac diastole.
Aortic component is audible-just ventral to horizontal line drawn drawn
through point of shoulder in left 4thICS.
Pulmonic component is audible –ventral & anterior to aortic valve at in left
3rd ICS.

12. THIRD HEART SOUND:
Low frequency sound produced with rapid filling of ventricles.
Occurs immediately afer 2nd sound.
Common n horses.
FOURTH HEART SOUND:
Associated with atrial contraction.
SEQUENCE:4-1-2-3
In horses 3rd & 4th may be
inaudible.

13.  Murmurs are audible successive sounds with
distinct duration as opposed to heart sound
which are short & transient.
 Prolonged audible vibrations occuring during
normal silent period of cardiac cycle.
 Problems resulting in heart murmurs are:
 Decreased viscosity.
 Condition producing increased cardiac
output.
 Abnormal blood flow.
 Temporary mumurs can be heard in colic
also.

14.  ECG provides record & measure of varying
potential difference that occur over surface
of body as result of electrical activity within
heart.
 RECORDING TECHNIQUES:
 Need quite place.
 Minimum interference.
 Rubber mat for horse.
 Dry area.
 Paper speed=25mm/s & sensitivity of
1cm=1mV.

15.  METAL ELECTRODE THAT
ARE CONNECTED TO LEG
BY RUBBER STRAP:
 Electrodes are applied on
forelimb caudal aspect of
distal radius just proximal
to carpal bone.
 Electrodes are applied on
hindlimb at cranial aspect
of of distal tibia above
point of hock.
 Chest electrode -5cm
behind point of elbow on
left ventral thorax.

16.  BIPOLAR LEAD SYSTEM
USING Y LEAD:
 Positive lead attached
over xiphisternum.
 Negative lead
attached over
manurium.
 Earth lead can be
attached over point
of shoulder.

17. Examine complete tracing to note any abnormal
rhythm.
Determine wether P wave,QRS complexes,T wave
are present for each heart beat .
Assess individual wave formation & measure
intervals.

18.  P wave:
 Represents artrial
depolarization.
 Appears M shaped.
NORMAL:
2 boxes (width)
4 boxes (height)

19.  PR interval:
 Beginning of P wave
to beginning of QRS
complex.
 Interval depends on
heart rate & shorten
as HR increases.
 In older horses-PR
interval lengthens.
PR interval:
3-61/2boxes (width)

20.  QRS complex:
 Represents ventricular
deporalizaton.
QRS interval:
3boxes (width)
25 boxes(height)

21.  T wave:
 Represents
ventricular
depolarization.
 Its extremely
sensitive to change
in HR with change
in amplitude &
polarity.

22.  QT interval:
 Beginning of QRS
comple to end of T
wave.
 Littl significance.
 Shorten with
increase in HR.
QT wave:
8-13 boxes(width)

23.  Developed by Dr. Jim Steel in 1950s.
 Its indirect method of assessing heart size &
is determined by measuring QRS complex
duration in milliseconds in lead I.II.III &
averaging the result.
 Average HS =113-116( >120 indicates above
average heart size).

24.  Equine cardiology Introduced by Pipers &
Hamlin in late 1970s.
 Useful in investigating congenital & acquired
heart disease.
 Techniques permits real time imaging of
heart,allowing quantitation of cardiac
dimensions,identification of lesions &
estimation of cardiac compensation &
myocardial failure.
 2.5-3.5MHz transducer is used.
 Pentration depth should be 24cm.

25. M –mode
B-mode/two dimensional real time
Continuous –wave doppler
Pulsed-wave doppler
Color-flow doppler

26. RIGHT PARASTERNAL LONG-AXIS VIEWS:
VIEW:taken from right hemithorax of horse witg transducer placed at
5th,4th/3rd ICS.
1.REFRENCE VIEW:4th ICS perpendicular to thoraxic wall.
Structures imaged are:TV,RA,IVS,IAS,LV,MV,LA,LVFW.
2. APICAL VIEW:transducer is rotated 90 degree counterclockwise from
refrence view.
Structure imaged are:RA,TV,RV,LV,IVS,LA.
3.LONG AXIS VIEW:rotated to 30 degree clockwise.
Struccture imaged are:RV,RA,LV,AO,PA.

27. RIGHT PARASTERNAL SHORT—AXIS VIEWS:
Transducer is rotated 90 degree counterclockwise from refrence
position .
Strcture imaged:RV,LV,RVW,LVW,chordae tendinae.

28.  Used to obtain hemodynamic information
from all four heart valves.
 Doppler sample of aortic outflow from LHS &
aortic diameter from RHS are measured &
resulting outflow combined with HR.

29.  Dyspnea,fatigue & prolonged elevation in HR
following exercise are suggestive of cardiac
insufficiency.
Clinical exercise testing is performed with treadmill inclined at slope oof 6
degree & then horse progress through trotting,cantering & galloping at
speed upto 12m/s.
Protocol:
3 min- 4m/s
90sec – 6m/s
1 min – 8,10,11,12 m/s until horse cannot maintaine pace with treadmill.
Most fit horses complete test upto 11m/s.

31.  Its defined as
inflammation of
pericardium.
 It may be fibrinous or
adhesive depending
on nature of
inflammation.
 Predominently occurs
in adults.

32.  Trauma from penetration of ingested FB or
external wound.
 Hematogenous spread of infection.
 Idiopathic pericarditis-characterised by
aseptic inflammatory exudate.
 HORSE:
 Streptococcus species.
 Tuberculosis.
 Actinobacillus equi.
 EHV-1 infection.

33.  As result of inflammation of pericardium
 Accumulation of fluid occurs.
 Deposition of fibrinous exudate produces friction
sound when pericardium & epicardium rub together.
 Friction sound replaced by muffling sound
 Accumulation of fluid results in compression of atria
& rt venticle.
 CHF follows
 Severe toxemia due to supparative pericarditis

34.  Increased HR.
 Pulse weak & thready.
 Muffled heart sound.
 Juglar vein distension.
 Ventral odema.
 Dyspnea.
 Alteration in mucous membrane.
 Prolonged capillary time.
 Clinical pathology:
 Leukocytosis & shift to left is detectable.
 Pericardial fluid for bacteriological examination.

35.  Hypermia.
 Deposition of
fibrin
 Gas may also be
present & fluid
may have putrid
odor.
 Embolic abscesses
may be present in
other organs.

36.  Pericardiocentesis done.
 Antibacterial treatment of specific infection.
 Braod spectrum antibiotic should given.
 Combination of penicillin & gentamicin is
common.
 NSAIDS given as an effective therapy.

37.  DEFINITION :-
 It denotes inflammation of the
endocardium. It affects the
lining of the heart as well as
the valves within it.
 Most of the cases are
caused by bacterial
infection. Infection may
gain entry through
 Direct adhesion to
undamaged endothelium.
 Through minor discontinuities
of valvular surfaces.
 By hematogenous route.

38.  Actinobacillus equi.
 Streptococcus spp
 Pseudomonas.
 Strongylu spp larvae.

39. Trauma to the endothelial surface
Exposure of collagen leading to platelet binding
Activation of extrinsic coagulation cascade
Deposition of fibrin
Formation of sterile platelet-fibrin deposits

40.  Endothelial damage may occur along the lines
of closure of valves in association with
turbulent flow.
 These areas of endothelial damage are
colonized by circulating bacteria where they
start growing.
 In large animals, endocarditis occur most
commonly secondary to a chronic infection
and a persistant bacteremia, whereas
certain organisms adhere directly to
endothelium

41. The major clinical abnormalities result from :-
 effect of endocarditis on heart function
 embolic showering of micro organisms
leading to infarction or infection
 valvular lesions which interfere with valve
function lead to cardiac insufficiency
 infected emboli produce infection or
abscesses in other organs like myocardium,
kidneys, joints

42.  In horses most common site:aortic valve.
 Left & right Arterioventricular valves being
2nd & 3rd prediliction sites

43.  Intermittent fever,
 Dull & deppressed.
 Heart murmur.
 Vegetative lesions in echocardiography.
 Coughing.
 Ventral odema.
CLNICAL PATHOLOGY:
neutrophilia
hyperfibrinogenemia
 A non-regenerative anemia

44.  Treatment is often unrewarding.
 Long term antibiotic therapy is required to cure
bacterial endocarditis.
 Penicillin and gentamicin are the drug of choice
for bacterial endocarditis..

45. THANK YOU