Pulmonary botryomycosis in a cat.

Area of Science:

• Veterinary Medicine
• Infectious Diseases
• Pathology

Background:

• Pulmonary botryomycosis is an exceptionally rare bacterial infection.
• This condition has not been previously documented in feline species.
• Chronic pulmonary lesions in cats can be challenging to treat, sometimes proving refractory to standard therapies like corticosteroids.

Purpose of the Study:

• To document the first reported case of pulmonary botryomycosis in a domestic cat.
• To describe the clinical, histopathological, and molecular findings of this rare infection.
• To emphasize the utility of combined diagnostic approaches in identifying unusual pathogens.

Main Methods:

• A 10-year-old spayed female domestic shorthair cat with chronic, corticosteroid-refractory pulmonary lesions was studied.
• Surgical lobectomy was performed on the right cranial and middle lung lobes.
• Histopathological examination identified pyogranulomatous inflammation with Splendore-Hoeppli material, and molecular analysis (16S rDNA sequencing) was used on formalin-fixed, paraffin-embedded tissue.

Main Results:

• Histopathology revealed extensive necrotizing and fibrosing pyogranulomatous inflammation.
• Characteristic club colonies of Gram-positive cocci surrounded by eosinophilic Splendore-Hoeppli material were observed.
• Molecular analysis indicated Staphylococcus spp. as the most likely causative agent, with the highest 16S rDNA sequence homology.

Conclusions:

• This case represents the first documented instance of pulmonary botryomycosis in a cat.
• The findings underscore the importance of integrating histopathological and molecular diagnostic techniques for rare infectious diseases.
• Accurate identification of the causative agent is crucial for appropriate treatment and understanding of feline pulmonary pathology.