The diagnosis of bovine tuberculosis (bTB) is based on the single intradermal tuberculin test (SIT), interferon gamma, and compulsory slaughter of reactor animals. Culture and PCR from fresh tissue are regarded as gold standard techniques for post-mortem confirmation, with the former being time-consuming and presenting moderate to low sensitivity and the latter presenting promising results. Histopathology has the advantage to identify and categorize lesions in both reactor and non-reactor animals. Therefore, this study aims to highlight the role of histopathology in the systematic diagnosis of bTB to shorten the time to disclose positive animals. Blood (212) and lymph node (681) samples were collected for serological, bacteriological, and histopathological analyses from a total of 230 cattle subjected to the Spanish bTB eradication program. Seventy-one lymph nodes and 59 cattle yielded a positive result to bacteriology, with 59 lymph nodes and 48 cattle presenting a positive result in real-time PCR from fresh tissue. Roughly 19% (40/212) of sera samples gave a positive result to ELISA. Tuberculosis-like lesions (TBLs) were observed in 11.9% (81/681) of the lymph nodes and 30.9% (71/230) of cattle. Noteworthy, TBLs were evidenced in 18 out of 83 SIT⁻ and real-time PCR and bacteriology negative animals, with 11/18 disclosing a positive result to Ziehl-Neelsen technique and two of them to ddPCR from paraffin blocks targeting IS6110. Six out of these 11 ZN⁺ corresponded with mesenteric LN and were confirmed positive to paratuberculosis. Histopathology yielded a sensitivity of 91.3% (CI₉₅ 83.2–99.4%) and a specificity of 84.4% (CI₉₅ 78.6–89.3%) with good agreement (κ = 0.626) when compared with real-time PCR. Our results confirm that histopathology allows a rapid confirmation of real-time PCR and bacteriology, emphasizing its contribution to bTB control and monitoring.

The actual role of certain viruses, such as coronavirus (RbCoV) and parvovirus (LBoV), in the digestive diseases of rabbitries remains poorly understood. For this reason, we conducted three different studies. In the detection frequency study, carried out using samples from both sick and healthy animals from farms with recurrent enteric problems, the presence and Cq values obtained by qPCR for these two viruses supported their implication in digestive disorders. In the lesional study, performed on samples from farms experiencing enteric disease outbreaks, the presence of lesions characteristic of both viruses was confirmed, along with other viral, bacterial, and parasitic agents that may have exacerbated the condition. Finally, in the epidemiological study, using samples from rabbits of different ages from farms with enteric problems, a higher prevalence of these viruses was observed during the growing phase, with a significant association with other bacterial agents such as Escherichia coli and Clostridium spiroforme. Overall, these results highlight the importance of both viruses in the aetiology of enteric disease and support their inclusion in the diagnostic enteric profile for rabbits.