SYPHILITIC MYOCARDITIS IN THE RABBIT

Area of Science:

• Veterinary Pathology
• Infectious Diseases
• Cardiovascular Pathology

Background:

• Treponema pallidum is the causative agent of syphilis.
• Syphilitic myocarditis is a known manifestation in humans, characterized by granulomatous inflammation.
• Animal models are crucial for understanding syphilis pathogenesis and developing treatments.

Purpose of the Study:

• To report the first cases of granulomatous myocarditis in rabbits infected with Treponema pallidum.
• To describe the gross and microscopic features of these lesions.
• To evaluate the potential of this finding as a model for studying syphilitic myocarditis.

Main Methods:

• Routine postmortem examinations of rabbits infected with Treponema pallidum.
• Gross pathological examination of cardiac lesions.
• Histopathological analysis of myocardial tissue, comparing findings to human syphilitic myocarditis.

Main Results:

• Six cases of pronounced granulomatous myocarditis were identified in infected rabbits.
• Lesions measured 1.0 cm or more in diameter.
• Histological features were consistent with human syphilitic myocarditis, although treponemata were not directly demonstrated in the lesions.

Conclusions:

• The observed myocarditis in rabbits is strongly suggestive of syphilitic myocarditis.
• These findings represent the first documented cases of syphilitic myocarditis and visceral syphilis in rabbits.
• This rabbit model may offer a valuable platform for further research into the cardiovascular manifestations of syphilis.