The heart has an enormous capacity to deal with transient increases in workload, as long as adequate intervals are provided for the recovery of nutritive and electrolyte levels. However, if the heart is forced to work against a sustained overload, it eventually becomes unable to deliver a normal output of blood. This leads to cardiac enlargement (dilatation and hypertrophy) which is the cardinal sign of heart disease

1. Cardiovascular system
Cardiomyopathy
Presented by
Dr. Mansoor Tariq
Assistant Professor
Department of
Veterinary Pathology

7. ➢ PERICARDIUM (fibrous or outer layer ) OF THE HEART
• Most diseases of the pericardium are secondary to disease processes
related to the heart, lungs, pleura, and other sites in the body.
• Clinically diagnose only when they cause an accumulation of fluid
within the pericardial sac.

8. ➢ HYDROPERICARDIUM
• Excessive accumulation of fluid
(transudate) within the pericardial sac.
Caused by those
factors responsible
for generalized or
local edema.

9. • Cause by compound fracture,
• Penetration of a broken rib into the
sac.
• also due to gas forming organism in
traumatic pericarditis.
➢ PNEUMOPERICARDIUM

10. ➢ HEMOPERICARDIUM
• an accumulation of pure blood in the pericardial sac.
Bleeding into the pericardial sac
Result from arterial rupture in dogs.
Rupture of the intra-pericardial
Aorta or pulmonary artery
in horses,

11. ➢ PERICARDITIS
• Caused by infectious agents
with an accumulation of
exudate within the sac.
• Infectious agents usually
reach the pericardium by
extension from surrounding
structures and/or by way of
the blood stream.

12. ➢ FIBRINOUS PERICARDITIS
• Usually d/t hematogenous infection,
occasionally extension from
adjacent tissues (ex. Haemophilus
and pasteurellosis in cattle, sheep,
pigs. Neonatal septicemias)
• Noninfectious—uremia
shaggy or bread / butter like
appearance of heart

13. ➢ SUPPURATIVE (PURULENT) PERICARDITIS
• accumulation of pus in the pericardial sac (due to pyogenic
bacteria).
• Due to traumatic perforation by a foreign body originating from the
reticulum (traumatic pericarditis).

14. ➢ TRAUMATIC PERICARDITIS
• A result of traumatic perforation of the pericardium by a foreign
body (wire / nail) originating in the reticulum (traumatic
reticulitis).
• swallowing foreign matter(wire/nail) reticulum
muscular contractions diaphragm pierced
opposite the apex of the heart entrance of bacteria along
with the foreign body gives rise to pericarditis.

18. ➢ ENDOCARDITIS
• Inflammation of the endocardium, which may be
• Valvular (affecting the valvular of the heart)
or
• Mural (affecting the chamber walls of the heart)
• Valvular endocarditis more frequently than mural.
• Usually bacterial, but occasionally parasitic and mycotic.

19. • A large number of bacteria are capable of causing endocarditis;
however, the manner by which these bacteria localize on a
valve is not clear.
• In the dog and horse, streptococci and staphylococci are most
commonly isolated from valvular lesions

21. Blackleg, mural endocarditis and myocarditis

23. ➢ MYOCARDITIS
• Inflammation of the myocardium, which is usually secondary to
a wide variety of systemic diseases.
• Causative agents may reach the myocardium by extension or by
the hematogenous route.
• Lesions are usually focal and may be overlooked on causal gross
inspection.

25. ➢ SUPPURATIVE MYOCARDITIS
• local suppurative myocarditis is associated with septicemia or
bacteremia when the organisms are carried to the heart from
suppurative processes.
• Suppurative inflammation by extension of process from a near
by inflamed organ or part e.g. from the pericardium,
endocardium, plura lungs.

26. ➢ SUPPURATIVE MYOCARDITIS
• Parvoviral myocarditis: small puppies and dogs.
• Canine Distemper also occasionally causes myocarditis
• West Nile virus—especially in birds, dogs

27. ➢ NON-SUPPURATIVE MYOCARDITIS
• Associated with various toxemias.
• The irritant may be mineral, poison or toxin from bacterial or
parasitic infections.

28. ➢ White muscle disease
Coagulative necrosis of the
myocardium is a lesion commonly
associated with vitamin E and
selenium deficiency (white muscle
disease) in lambs, calves, and pigs.

30. • Heart failure is the inability of the heart to maintain adequate
circulation. It occurs when blood returning to the heart cannot
be pumped out at a rate sufficient to meet the metabolic
demands of the body.
• leading cause of death in people, largely due to atherosclerosis
and the high prevalence of hypertension.
• Heart failure occurs in animals as well, but the incidence is
much lower.
• Heart failure can be broken down into two broad categories,
acute heart failure and chronic (or congestive) heart
failure.

31. Congestive heart failure, also known as chronic heart failure, is
the result of failure of the heart to maintain adequate circulation over
a period of time. General causes of chronic heart failure include:
sustained systolic pressure overload,
sustained volume overload
loss of myocardial contractile capacity
interference with ventricular filling during diastole,
Congestive heart failure is often further divided into right-sided or
left-sided heart failure,
Failure on one side usually leads to failure on the other, so it doesn’t
matter all that much.

32. The body makes many adjustments, or compensations, when
faced with chronic heart failure.
These adjustments to chronic heart failure can be divided into two
main categories – peripheral and cardiac.
Peripheral adjustments for insufficient cardiac output would
include trying to maintain blood flow to vital organs, increasing
the amount of red blood cells to help with oxygenation, and
controlling the blood volume to decrease the load on the heart.
Cardiac adjustments to heart failure are those compensations that
allow the heart to respond to circulatory demands over and above
those of the normal animal at rest.

33. ➢Left-sided heart failure (Pulmonary congestion)
If the left side of the heart
fails to pump blood back
to the body efficiently,
blood begins to back up
in the pulmonary veins.
The pressure forces fluid
into the lungs, preventing
efficiently transfer of oxygen
to the blood.

34. ➢ LEFT-SIDED HEART FAILURE
• Result in the coughing, shortness of breath and fatigue
• Common causes of left heart failure include:
(1) myocarditis,
(2) degeneration of the myocardium,
(3) stenosis and insufficiency of the mitral and semilunar valves, and
(4) Congenital heart diseases.
• Coughing is usually the most distinctive and alarming feature of
left heart failure in the dog. Productive cough increased
production of mucous, stimulated by severe lung congestion.

35. ➢ RIGHT-SIDED HEART FAILURE: (Generalize Edema)
When the right side of the heart
is unable to pump blood to the
lungs as quickly as it return from
the body, the veins become congested.
The pressure is build until fluid is forced
out through capillary walls.

36. ➢ RIGHT-SIDED HEART FAILURE
• Clinical signs and symptoms include dyspnea on exertion, cough, swelling of
ankles and legs.
• Common causes of right-heart failure include:
(1) left-sided heart failure,
(2) myocardial degeneration,
(3) myocarditis,
(4) factors that cause increased pulmonary resistance,
(5) hydro-pericardium,
(6) exudative pericarditis
(7) endocarditis and defective tricuspid valves.
• In the horse and cow, a dependent subcutaneous edema is expected
(subcutaneous edema is absent in other species).
• In the dog, the predominant accumulation of fluid is in the peritoneal cavity
(ascites);
• In the cat, fluid is most commonly encountered in the thorax (hydrothorax).

38. HYPERTROPHY OF THE HEART
Cardiac enlargement is the "cardinal sign" of heart disease.
Myocardial hypertrophy is an increase in bulk of cardiac muscle due
to an increase in size of component fibers.
Expected response of the heart to systolic pressure overload is
concentric hypertrophy,
while the response to diastolic volume overload is eccentric
hypertrophy.

39. • Concentric hypertrophy (pressure overload hypertrophy)
• Occurs in response to chronic pressure-overloading caused
by systemic or pulmonary hypertension
• Concentric myocardial hypertrophy is characterized by
increased ventricular wall thickness and decreased ventricular
chamber volume.
• Concentric hypertrophy must be accompanied by a
compensatory increase in heart rate in order to maintain
cardiac output.

40. Eccentric hypertrophy (volume overload hypertrophy)
occurs in response to chronic pressure-overloading caused by,
systemic or pulmonary hypertension
Eccentric hypertrophy is characterized by increased ventricular
chamber volume with normal or decreased ventricular wall
thickness.
However, the total cardiac weight is increased due to a greater
muscle mass surrounding the dilated chamber.

41. • Arteries
• Veins
• Pericardium
• Hydropericardium
• Hemopericardium
• Pnemopericardium
• Pyopericardium
• Pericarditis
• Epicardium
• Endocardium
• Myocardium
Heart Vascular System

42. VASCULITIS
ARTERITIS
PHLEBITIS

43. • Vasculitis is defined as an inflammation of vessels characterized
by presence of inflammatory cells within and around vessel
walls
• Lesions can be more specifically designated as
arteritis (arteries),
phlebitis (veins), or
omphalophlebitis (umbilical veins)
• Vasculitis is commonly associated with septicemic, viremic, and
toxemic diseases
• Endothelial cell damage is a primary factor in the pathogenesis
of many diseases including: canine herpes, infectious canine
hepatitis, swine fever, heartwater, African horse sickness,
epizootic hemorrhagic disease, bluetongue and
endotoxemia.

44. Artery is made up of several layers:
an inner lining called the endothelium, an elastic membrane that
allows the artery to expand and contract,
A layer of smooth muscle, and
A layer of connective tissue.

45. Arteritis is the inflammation of the walls of arteries,
Lesions associated with vasculitis vary and, depending on the
damage, can be seen as serous, fibrinous, or hemorrhagic foci
around the vessels.
Arteritis is a complex disorder that is still not entirely understood.
A complication of arteritis is thrombosis, which can be fatal.
Arteritis is an important lesion in
i) Viral Diseases
a) Equine viral arteritis
b) Malignant catarrhal fever (MCF)
c) Blue tongue disease
d) Bovine viral diarrhea (BVD)
ii) Bacterial Diseases
a) Salmonellosis
iii) Fungal Infections
a) Aspergillosis
iv) Parasitic Infection
a) Equine strongylosis
b) Dirophilerisis (D. imitus)

46. The wall of the vessel is disrupted, so cells stick there, & make thrombus

49. • Arteriosclerosis is an umbrella term for several types of changes
that cause hardening of arteries.
• Arteriosclerosis without lipid deposition can occur due to
increased connective tissue,
vascular mineralization (Johne’s disease), or hyaline
degeneration (Coronary arteries of old dogs).
• Ateriosclerosis with lipid deposition, also known as
atherosclerosis, is common in humans but infrequent in animals.

50. ARTERIOSCLEROSIS
Characterized by thickening and loss of elasticity of the arterial walls;
popularly called “hardening of the arteries”.
Plaque is made of fatty substances, cholesterol, waste products
from the cells, calcium, and fibrin material that helps clot blood.

51. Category of arteriosclerosis
Atherosclerosis,
The most common type, in which plaques of fatty deposits form in
the inner layer (TUNICA INTIMA) of the arteries
Medial sclerosis
Destruction of muscle and elastic fibers and formation of calcium
deposits

53. A injury to the middle or
muscular layer of the
arterial wall (tunica media)
can predispose the vessel to
stretching of the inner
and
outer layers of the artery
and
the formation of a sac.

54. ANEURYSM
a sac formed by the localized dilatation
of the wall of blood vessel.
An aneurysm is a localized dilatation of
an artery. Dilatations of the veins are
called varicosities rather than aneurysms.
A true aneurysm results from formation of a sac by the
arterial all three walls layer. It is most often associated with
atherosclerosis.
A false aneurysm usually is caused by trauma.
In this case, the wall of the blood vessel is ruptured and blood
escapes into surrounding tissues and forms a clot (hematoma).

55. Pseudoaneurysm
True Aneurysm

56. Causes
An aneurysm is the enlargement of an artery caused by weakness
in the arterial wall. Often there are no symptoms, but a ruptured
aneurysm can lead to death.
Rarely but can been seen in older animals.
Aneurysm have variety of causes including high blood pressure
and atheroscleriosis, trauma, heredity and abnormal blood flow at
the junction where arteries come together.

58. Classification of aneurysms
All three tunica layers are involved in true aneurysms
(fusiform and saccular).
In false aneurysms, blood escapes between tunica layers and they separate.
If the separation continues, a clot may form, resulting in a dissecting

59. An aneurysm is a localized dilatation of an artery.
Dilatations of the veins are called varicosities (Varicose) rather
than aneurysms.
Aortitis: Inflammatory condition of aorta
Arteritis: Inflammatory condition of artery
Capillaritis: Inflammatory condition of capillary
Phlebitis: Inflammatory condition of vein

62. • Phlebitis is the inflammation of veins characterized by
presence of inflammatory exudate, thickening of the wall
and dilation of the lumen.
• The condition is less common than arteritis.
• Some time occurs with thrombophelibitis and Omphalophlebitis.
• Omphalophlebitis in which the umbilical veins, particularly in farm
animals, become infected and inflamed after birth.
• Acute phlebitis occurs in "navel infection" (omphalophlebitis) of
calves, lambs and foals.
• Some parasites such as Schistosoma sp (blood fluke trematode)
cause parasitic phlebitis.

64. Etiology/ Occurrence
• Naval infection in calves
• Uterine infections
• In jugular vein due to improper intravenous infection.
• Varicose veins are dilated and elongated veins following
irregular and tortuous course
Macroscopic feature
• Wall of vein is thickened.
• Vein contain large thick necrotic material
• Lumen dilated
• Inner surface of vein is rough and hyperemic.
• Infiltration of neutrophils in the wall of veins
• Wall of vein becomes thick due to inflammatory cells and/
or proliferation of fibrous tissue.

66. Horses have approx. 8000 small lymph nodes,
compared to humans’ approx. 600 larger ones
and 60 in the dog.

69. Lymphatic System (Lymph)

70. • The lymphatic system is a network of organs (i.e tonsils,
spleen and thymus), cells (lymphocytes), ducts (lymph
vessels), and glands (lymph nodes) can be found throughout
the body.
• Lymph travels through the body along lymphatic vessels and
collects fats, bacteria, and other waste products from cells and
tissues.
• The lymph nodes then filter these harmful materials out of
the fluid and produce more white blood cells to fight off the
infection.
Lymphatic system

71. PATHOLOGICAL CONDITION OF LYMPHATIC SYSTEM
• Lymphangitis is an inflammation of the lymphatic system,
which is a major component of the immune system.
• Lymph adenitis Inflammation of lymph glands
• Lymphatic system problems can include infections, blockage,
and cancer.
• Lymphoid leukaemias and lymphomas are now considered to
be tumours,
• “Leukaemia" when tumour in the blood or marrow and
• “Lymphoma" when tumour in lymphatic tissue.
• Together they called “Lymphoid malignancy"

72. LYMPHEDEMA
• If lymphatic system not working properly, fluid builds in body
tissues and causes swelling, called Lymphedema.
• Lymph edema classified into primary and secondary
• Primary lymph edema is usually congenital and hereditary due
to anomalous development of the lymphatic system.
• Secondary lymph edema occurs because of obstruction of
previous normal lymphatic duct due to infection, inflammation,
tumour, or injury.
• Lymph edema is because of the predispose affected area,
usually limb, to secondary bacterial infection and poor wound
healing.

73. Lymphatic filariasis
Elephantiasis

74. • Lymphangitis occurs when viruses and bacteria invade the
vessels of the lymphatic system, typically through an infected
cut or wound.
• Lymphangitis occurs when bacteria or viruses enter the
lymphatic channels. They may enter through a cut or wound, or
by an existing infection.
• Bronchial lymph glands are involved and inflamed in pneumonia
cases,
• In mastitis, enlarged supramammary, iliac and lumbar lymph
nodes. Also Mycobacterium paratuberculosis & Brucella abortus
infection
• Pharynges are involve due to tonsils swelling in rhinitis or in
infection.