Caprine tuberculosis (TB) is a zoonosis caused by members of theMycobacterium tuberculosiscomplex (MTBC). Caprine TB eradication programmes are based mainly on intradermal tuberculin tests and slaughterhouse surveillance. Different factors may affect the performance of the TB diagnostic tests used in caprine herds and, therefore, their ability to detect infected animals. The present study evaluates the effect of the fraudulent administration of two anti-inflammatory substances, dexamethasone and ketoprofen, on the performance of the TB diagnostic techniques used in goats, as well as the suitability of high performance liquid chromatography (HPLC) for their detection in hair samples. The animals (n= 90) were distributed in three groups: (1) a group treated with dexamethasone (n= 30); a second group treated with ketoprofen (n= 30); and a third non-treated control group (n= 30). Both dexamethasone and ketoprofen groups were subjected to intramuscular inoculation with the substances 48 h after the administration of bovine and avian purified protein derivatives (PPDs), that is, 24 h before the tests were interpreted. All the animals were subjected to the single and comparative intradermal tuberculin (SIT and CIT, respectively) tests, interferon-gamma release assay (IGRA) and P22 ELISA. The number of SIT test reactors was significantly lower in the dexamethasone (p= 0.001) and ketoprofen (p< 0.001) groups 72 h after the bovine PPD inoculation compared with the control group. A significantly higher number of positive reactors to IGRA was detected within the dexamethasone group (p= 0.016) 72 h after PPD administration compared to the control group. Dexamethasone and ketoprofen detection in either hair or serum samples was challenging when using HPLC since these substances were not detected in animals whose skin fold thickness (SFT) was reduced, what could be an issue if they are used for fraudulent purposes. In conclusion, the parenteral administration of dexamethasone or ketoprofen 48 h after the PPDs administration can significantly reduce the increase in SFT (mm) and subsequently the number of positive reactors to SIT test.

Paratuberculosis (PTB) and tuberculosis (TB) are two mycobacterial diseases with a severe economic and health impact on domestic ruminants. The ante mortem diagnosis of PTB is hampered, among other factors, by the limited sensitivity of all the available diagnostic techniques. Since TB-infected goats subjected to the comparative intradermal tuberculin test (CITT) may experience a booster effect on their antibody titer and a potential enhancement to the sensitivity of humoral techniques for tuberculosis, in the present study we aimed to evaluate this diagnostic strategy on the humoral diagnosis of PTB in serum and milk samples collected from a caprine herd that was TB free and PTB infected. The results from 120 goats indicated a significant increase (p < 0.001) in the quantitative response detected using an ELISA technique, conducted using serum and milk samples taken 15 and 30 days after performing a CITT (day 0 of the study); although, it did not translate into a significant increase in the number of reactors during any of the testing events (0, 3,15, 30 and 60 days post-CITT). Additionally, the number of ELISA-positive animals was higher for the serum versus the milk samples at both 15 and 30 days post-CITT. The increase in the quantitative ELISA result suggested a diagnostic strategy that maximizes ELISA sensitivity, mainly using serum samples, in PTB-infected herds; although, it may depend on individual differences and the interpretation criteria.

Goats represent a significant reservoir for tuberculosis (TB) in animals, contributing notably to public and animal health challenges, causing economic repercussions. Ante mortem diagnosis of TB is hindered by the limited sensitivity of available techniques and false-positive results from other mycobacterial infections, such as paratuberculosis (PTB). Nuclear Magnetic Resonance (NMR)-based metabolomics provides unique fingerprinting of the disease’s metabolic status, making it a promising diagnostic tool. However, conventional high-resolution NMR has limitations in veterinary practice, where high costs and large equipment size are major constraints. Benchtop NMR spectrometer is proposed as a compact, cost-effective alternative for livestock farms. The study aimed to evaluate NMR-based metabolomics as a diagnostic tool and transfer it from high-resolution to benchtop NMR spectrometers in an animal setting. Serum samples from TB-infected, PTB-infected ( n = 16), and healthy control goats (HC) were analyzed by both high-resolution and benchtop NMR spectroscopy. Multivariate statistical analysis successfully differentiated groups on the basis of their metabolic profiles with both spectrometers. We identified that betaine, glucose, glycerol, and lactate are significantly capable of distinguishing between the three groups. Additionally, 3-hydroxybutyrate, creatine, glutamate, leucine, lysine, phenylalanine, threonine, and tyrosine further differentiate TB from HC. Acetate, creatine, glutamate, isoleucine, leucine, and lysine distinguish TB from PTB, while 3-hydroxybutyrate and phenylalanine serve to differentiate PTB from HC. Analyses with both high-resolution and benchtop spectrometers demonstrated high sensitivity and accuracy and reliable metabolite identification. These findings highlight NMR’s spectroscopy potential to identify biomarkers associated with TB and PTB infection, improving health management in livestock.

Background: Caprine tuberculosis (cTB), caused by members of the Mycobacterium tuberculosis complex (MTBC) represents a significant concern for animal and public health. Antibody-based diagnostic tests have emerged as promising tools to complement ante-mortem official diagnostic techniques in ruminants, which mainly use serum, although alternative, easier-to-collect samples, such as milk, oral fluid, or feces, could also be used. The objective of this exploratory study was to evaluate the reactivity of an in-house P22 enzyme-linked immunosorbent assay (ELISA) in fecal samples from goats belonging to cTB-infected herds, using serum P22 ELISA and official diagnostic tests as comparators. Methods: Serum and fecal samples were collected from 51 and 42 adult female goats from a high-prevalence herd (n = 149) and a low-prevalence herd (n = 220), respectively, which defecated during sampling. These animals were subjected to official diagnostic techniques: single and comparative intradermal tuberculin tests and the interferon-gamma release assay. As no TB-free herd was available, a preliminary fecal cut-off was established by receiver operating characteristic analysis using serum P22 ELISA as the reference classification. Results: The percentage of positive animals in fecal samples from the high-prevalence herd was 68.6%, while no positive results were observed in the low-prevalence herd. Serum samples showed a higher number of positives in both herds compared to fecal samples (p < 0.05). The agreement between official diagnostic techniques and P22 ELISA (using serum or feces) was slight in general terms. When a combined classification based on all official tests was used as the reference, fecal P22 ELISA detected 58.0% of test-positive goats, none of them in the low-prevalence herd. Conclusions: Under the conditions of this field study (no TB-free controls or post-mortem confirmation of infection were available), fecal P22 ELISA showed limited reactivity compared with serum, particularly in the low-prevalence herd, suggesting limited usefulness for antibody detection in TB infected goats.

Nuclear magnetic resonance (NMR)-based metabolomics has emerged as a robust and reproducible analytical platform for investigating the molecular mechanisms underlying disease and identifying candidate biomarkers with potential clinical relevance. Although initially developed for biomedical research, its application in veterinary medicine has expanded rapidly during the last decade, driven by the growing demand for precision medicine approaches capable of improving disease diagnosis, prognosis and therapeutic monitoring. This review summarizes the current landscape of NMR metabolomics in veterinary medicine, highlighting its applications across major clinical areas, including oncology, infectious, respiratory, digestive, renal, endocrine and musculoskeletal diseases. Collectively, the available evidence demonstrates that NMR metabolomics consistently identifies disease-associated metabolic alterations, providing novel insights into pathophysiology while supporting biomarker discovery in naturally occurring animal diseases. Beyond current clinical applications, we discuss the major challenges that continue to limit routine implementation, including biological variability, standardization of analytical workflows, multicentre validation and clinical translation. Particular attention is given to recent technological advances, such as benchtop NMR instrumentation, artificial intelligence-assisted data analysis, multi-omics integration and the development of collaborative networks and standardized platforms. Together, these advances position NMR metabolomics as a promising technology to support precision veterinary medicine, facilitating its transition from biomarker discovery to routine clinical implementation.