Eosinophilic Granulomatous Myocarditis in Two Pigs.

Area of Science:

• Veterinary Pathology
• Comparative Pathology

Background:

• Eosinophilic myocarditis is a rare human cardiac inflammatory disease.
• Animal cases of eosinophilic myocarditis are seldom documented.

Purpose of the Study:

• To describe two cases of idiopathic eosinophilic granulomatous myocarditis in pigs.
• To compare the porcine condition to human eosinophilic myocarditis.
• To investigate potential causes, including infectious agents.

Main Methods:

• Gross and histopathological examination of cardiac tissues.
• Immunohistochemistry for porcine circovirus type 2 (PCV2) and Toxoplasma gondii.
• In-situ hybridization and quantitative PCR for PCV2 and porcine circovirus type 3.
• Aerobic bacterial culture of myocardium.

Main Results:

• Two unrelated pigs presented with sudden death and marked cardiomegaly.
• Gross findings included epicardial nodules and pale areas.
• Histopathology revealed cardiomyocyte loss with eosinophilic and epithelioid macrophage infiltrate, and fibrosis.
• Infectious agents (PCV2, PCV3, T. gondii, bacteria) were not detected.

Conclusions:

• Idiopathic eosinophilic granulomatous myocarditis can occur in pigs, presenting similarly to the human disease.
• The condition was associated with sudden death in these porcine cases.
• Common infectious causes were ruled out, suggesting an idiopathic etiology.