Approximately 30 distinct Mycoplasma species have been isolated from cattle, but only a few are pathogenic and can cause serious respiratory diseases. Consequently, this study aimed to identify Mycoplasma spp. infections in cattle with bovine respiratory disease (BRD), considering factors such as animal demographics, concurrent infections with other pathogens, post-mortem clinical findings and histological examinations, and seasonality. A total of 326 samples were collected from 322 cattle that had died from BRD in Northwestern Italy. A total of 54 animals (16.8%) tested positive for Mycoplasma spp., and Mycoplasma bovis (n = 22, 40.7%) and Mycoplasma dispar (n = 13, 24.1%) were the most frequently detected species among the examined cattle. Among positive cattle, those aged five months or younger were approximately five times more likely to be infected by Mycoplasma dispar than by Mycoplasma bovis compared to those older than five months (proportional incidence ratio: 5.1, 95% CI 1.2–21.2). The main bacterial pathogens identified in cattle exhibiting co-infection was Pasteurella multocida, whereas the main viral pathogens were BRSV and BoHV-1. Histopathological investigations predominantly revealed catarrhal bronchopneumonia or purulent catarrhal bronchopneumonia among the examined cattle. Finally, Mycoplasma hyopharyngis, a species isolated from the pharyngeal and nasal cavities of pigs so far, was detected for the first time in the pneumonic lung of a bovine infected with BRD. Further investigations are necessary to thoroughly characterize its host range and pathogenic potential.

Selective symmetrical encephalomalacia (SSE) is a rare neurological disorder characterized by bilateral and symmetrical areas of malacia within specific regions of the central nervous system and has been reported in humans and several animal species. This report describes a case of SSE in a six-month-old Maine Coon crossbred kitten from Italy that presented with central vestibular dysfunction, rapidly progressive neurological deterioration, proprioceptive deficits, respiratory impairment, seizures, and abnormal vocalization. Clinical evaluation, hematological and biochemical analyses, and ancillary diagnostic testing were performed to investigate the underlying cause and evaluate differential diagnoses. Despite supportive care, the animal died naturally a few days after the onset of clinical signs. A complete postmortem examination, including histopathological evaluation of the central nervous system, was subsequently performed. Neuropathological analysis revealed multifocal, bilateral, and symmetrical malacic and spongiform lesions affecting multiple brain regions, compatible with an SSE pattern. Comparison with previously reported cases in humans and dogs showed marked similarities in lesion distribution and morphology. This case expands the limited knowledge of SSE-like neuropathological lesions in cats and highlights the value of neuropathological examination in the diagnosis of rare neurological disorders presenting with rapidly progressive clinical signs.