JPC SYSTEMIC PATHOLOGY

Cardiovascular system

April 2022

C-M11

 

SIGNALMENT (JPC #3106248): 4-year old female Santa Gertrudis cow 

 

HISTORY: 2 week duration of illness with appetite changes and scours

 

HISTOPATHOLOGIC DESCRIPTION: Heart: The epicardium is diffusely replaced by an adherent mat up to 1 cm thick composed of plump, reactive fibroblasts interspersed with bundles of variably mature collagen fibers and perpendicularly-oriented small caliber blood vessels (granulation tissue). Multifocally, this granulation tissue extends into and separates epicardial adipocytes. Throughout the superficial granulation tissue, there is diffuse infiltration by abundant viable and degenerate neutrophils, macrophages, lymphocytes, and plasma cells. The overlying surface is composed of eosinophilic cellular and karyorrectic debris (necrosis) admixed with previously described inflammatory cells, pale eosinophilic fibrillar material (fibrin), and large colonies of 2 µm coccobacilli. Within the superficial myocardium, the perimysium is expanded by increased clear space (edema) and low numbers of lymphocytes, plasma cells, and macrophages. Diffusely, adipocytes exhibit variation in cell size (atrophy). Multifocally within the myocardium, few cardiac myocytes are expanded by oval 40 x 60 µm protozoal cysts containing numerous elongate 3 x 10 µm basophilic bradyzoites (Sarcocystis schizonts).

 

MORPHOLOGIC DIAGNOSIS: 1. Heart: Pericarditis and epicarditis, fibrinosuppurative, diffuse, severe, with numerous superficial coccobacilli, Santa Gertrudis, bovine.   

2. Heart, myocardium: Sarcocysts. 

 

CAUSE: Penetrating cardiac trauma

 

CONDITION: Traumatic pericarditis

 

SYNONYMS: Hardware disease, traumatic reticuloperitonitis (TRP), fibrinous traumatic reticuloperitonitis, purulent pericarditis, fibrinous pericarditis, traumatic reticulitis

 

GENERAL DISCUSSION: 

• Traumatic pericarditis results from penetration of the pericardial sac, resulting in inflammation of the pericardium and accumulation of serous or fibrinous inflammatory products
• Traumatic reticuloperitonitis (TRP) in cattle is commonly caused by ingestion of long, thin, sharp foreign bodies (i.e. wire, nails) which penetrate the reticulum, peritoneum, diaphragm, and pericardial sac 
• Prophylactic use of ingested magnets and replacement of baling wire with twine has contributed to the decreased incidence of traumatic reticuloperitonitis 

 

PATHOGENESIS: 

• Ruminants: Ingestion of sharp metal foreign body (wire or nail) > settles in bottom of rumen and pushed back into reticulum > penetration of reticulum wall > inoculation of peritoneum, diaphragm, pleural space and/or pericardium with mixed bacteria > acute local peritonitis, pneumonia and pleuritis, fibrinous pericarditis and epicarditis > adhesions between reticulum and adjacent structures > (chronic cases) constrictive pericarditis
• Infections commonly attributed to Trueperella (formerly Arcanobacterium) pyogenes and Fusobacterium necrophorum
• Rarely, perforation of coronary or larger regional arteries can cause severe hemorrhage and sudden death

 

TYPICAL CLINICAL FINDINGS:

• Sternal edema and distension of the jugular vein secondary to cardiac insufficiency
• Standing with arched back
• Decreased milk production
• Cardiac auscultation: loud pericardial friction rub
• Septicemia possible but uncommon 

 

TYPICAL GROSS FINDINGS:  

• Heart: Markedly thickened pericardial sac with extensive fibrinous exudate loosely attached to the epicardium, epicardial hemorrhage

• Firm fibrous adhesions that are often mineralized
• Pericardial fluid is often fibrinopurulent
• Constrictive pericarditis will result in secondary right-sided heart failure

• Pleural: Fibrinous pleuritis and pyothorax
• Abdominal cavity: Peritonitis with fibrin deposition and firm adhesions
• Reticulum: Serosal ulcerations and/or firm adhesions
• Foreign body rarely found 

 

TYPICAL LIGHT MICROSCOPIC FINDINGS:

• Reactive pericardium and epicardium; expanded by granulation tissue and fibrin
• Fibrinosuppurative infiltrates and large areas of necrosis
• Multifocal large colonies of bacteria through the pericardium and epicardium, extending into the myocardium

 

ADDITIONAL DIAGNOSTIC TESTS:  

• Pericardiocentesis and thoracocentesis: foul smelling cloudy exudate

• CBC: Moderate to severe inflammatory leukogram
• Chemistry: Elevated total plasma proteins, globulins, fibrinogen, serum amyloid A, and haptoglobin
• Echocardiography
• Ultrasonography

 

DIFFERENTIAL DIAGNOSIS:

• Fibrinous pericarditis (cattle): 

• Pasteurellosis, blackleg (Clostridium chauveoi), sporadic bovine encephalomyelitis (Chlamydia pecorum), contagious bovine pleuropneumonia (Mycoplasma mycoidies subsp. mycoides), bacillary hemoglobinuria (Clostridium novyi type D)
• Neonatal coliform infections that enter via the umbilicus

 

COMPARATIVE PATHOLOGY:

Traumatic pericarditis: 

• TRP occurs in all ruminant species
• New World and Old World camelids: Less common due to selective feeding behavior
• Cat, dog and horse: Associated with pyothorax from migrating grass awns “foxtail,” Hordeum glaucum and H. leparinum

 

Infectious pericarditis:

• Swine: Fibrinous pericarditis from Glasser’s disease (Haemophilus parasuis), pasteurellosis, porcine enzootic pneumonia (Mycoplasma hyopneumoniae), rarely from salmonellosis
• Sheep: Commonly from pasteurellosis
• Horse: Mycoplasma felis causes pericarditis and pleuritis; streptococcal pericarditis may coexist with polyarthritis; can be associated with the mare reproductive loss syndrome
• Goat: Rarely from contagious caprine pleuropneumonia (CCP, Mycoplasma capricolum subsp. capripneumoniae)
• Cat: Rarely from feline infectious peritonitis 
• Guinea pigs, NHPs: Streptococcus pneumoniae (C-B02), a Gram-positive diplococcus
• Polyserositis in ducks and other waterfowl: Reimerella anatipestifer, a Gram-negative bacillus, causes septicemia in waterfowl resulting in exudative and fibrinous polyserositis, sinusitis, bronchopneumonia, and myocarditis; bacteria may be found extracellularly or in macrophages

 

References:

1. Fenton H, McManamon R, Howerth EW. Anseriformes, Ciconiiformes, Charadriiformes, and Gruiformes. In: Terio KA, McAloose D, St. Leger J, eds. Pathology of Wildlife and Zoo Animals. San Diego, CA: Elsevier; 2018: 708.
2. Francoz D. Traumatic Reticuloperitonitis (Hardware Disease, Traumatic Reticulitis). In: Smith BP, ed. Large Animal Internal Medicine. 6^th ed. St. Louis, MO: Elsevier; 2020: 883-885.
3. Reef VB. Diseases of the Cardiovascular System. In: Smith BP, ed. Large Animal Internal Medicine. 6^th ed. St. Louis, MO: Elsevier; 2020: 499-503.
4. Miller LM, Gal A. Cardiovascular System and Lymphatic Vessels. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 7th ed. St. Louis, MO: Elsevier; 2022: 677, 688.
5. Lopez A, Martinson SA. Respiratory System, Thoracic Cavities, Mediastinum, and Pleurae. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 7th ed. St. Louis, MO: Elsevier; 2022: 619.
6. Spagnoli ST, Gelberg HB. Alimentary System and the Peritoneum, Omentum, Mesentery, and Peritoneal Cavity. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 7th ed. St. Louis, MO: Elsevier; 2022: 466.
7. Uzal FA, Plattner BL, Hostetter JM. Alimentary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 2. 6th ed. St. Louis, MO: Elsevier; 2016:38-39.

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