Abstract
Background:
Sphingomonas spp. are ubiquitously distributed free-living microorganisms in the natural environment. One of the representatives of the family, called Sphingomonas paucimobilis, is known as an opportunistic pathogen in humans responsible for bone and soft tissue infections.

Case Description:
In January 2024, signs of drooling, tongue rolling, and local edema in the pharyngeal region were observed in a male beef-dairy cross. Clinical examination revealed several ulcerative lesions on the tongue. The bull was not treated with antibiotics due to the impending slaughter of the entire lot of cattle. During the slaughter of 14 dairy-beef bulls, it was found that 13 of them had necrotic ulcerative lesions on the dorsal and lateral surfaces of their tongues. Tongue samples from only two of the bulls were sent from the slaughterhouse for diagnostic analysis. A pure bacterial culture was isolated from the tongue ulcers following the culturing process. As a result of bacteriological tests on these samples, a strain of S. paucimobilis was isolated, suggesting a possible association with the condition's cause. Over the past two decades, this microorganism has been noted in cases of mastitis in dairy cows in both the USA and the Republic of Türkiye, as well as in instances of polyarthritis in dogs within the USA. Additionally, S. paucimobilis has been reported in cases of septicemia and pneumonia in calves and cows in the Republic of Türkiye.

Conclusion:
These findings raise concerns about the impact of S. paucimobilis on livestock health and the potential negative effects on farm welfare. Additionally, these bacteria exhibit reduced susceptibility to antibiotics, highlighting the necessity for surveillance to protect both animal and human health.

Key words: Beef-dairy crossbred; Bulls; Sphingomonas paucimobilis; Tongue ulcers.