Bovine Endocarditis Associated with Mycoplasma bovis

Area of Science:

• Veterinary Pathology
• Bovine Infectious Diseases
• Microbiology

Background:

• Mycoplasma bovis is a significant cattle pathogen, commonly causing respiratory and reproductive diseases.
• Bovine endocarditis is a rare condition, with no prior documented association with Mycoplasma bovis.

Purpose of the Study:

• To investigate the etiology of a unique form of bovine endocarditis observed in Japanese slaughterhouses.
• To determine if Mycoplasma bovis is associated with these specific endocardial lesions.

Main Methods:

• Necropsy examination of five cattle carcasses with characteristic endocardial lesions.
• Isolation and identification of Mycoplasma bovis from affected tissues.
• Immunohistochemical detection of Mycoplasma bovis antigen within the lesions.

Main Results:

• Caseated lesions (5-12 cm diameter) were found on the endocardial surface of the left atrium in all five cattle.
• Mycoplasma bovis was successfully isolated from these lesions.
• Mycoplasma bovis antigen was confirmed immunohistochemically within the lesions, with no evidence of valve or right-sided heart involvement.

Conclusions:

• The findings strongly suggest Mycoplasma bovis as the sole causative agent of the observed bovine endocarditis.
• This study represents the first documented evidence of Mycoplasma bovis-associated endocarditis in cattle.