Abstract: Consumers expect ruminants to graze outdoors and flocks to be of a reasonable size. Dairy goats can be kept outdoors (natural) or indoors. The farms we studied in the Centre-West of France were either organic or conventional, and all used pastures and tended to meet consumer demand for naturalness. We obtained information through semi-directed interviews. Dairy goats are susceptible to gastrointestinal infections when using pastures and this was one of the main health problems mentioned by organic farmers. There are a very limited number of medicines available for lactating dairy goats and farmers can use complementary and alternative veterinary medicine (CAVM), where they are completely autonomous in their choice. Homeopathy, phytotherapy and aromatherapy were used for various health problems on almost all the farms surveyed. Dairy goats in France are frequently bred in large farms indoors but there are smaller farms where the goats are kept outdoors on pastures. Information was gained by means of semi-directive interviews of dairy goat farmers of Centre-West France. They were either conventional or organic farms. Due to the limited drugs available for dairy goats during lactation they turned largely to complementary and alternative veterinary medicines (CAVM). Homeopathy, phytotherapy and aromatherapy were used for various health problems in almost all the farms surveyed. Herd size and farm area were negatively associated with the complex use of CAVM, possibly due to the workload on larger farms. Some CAVM were more used in relation to the management of farms: aromatherapy in organic and homeopathy in cheese making farms. The farmers with higher level of education were more likely to employ phytotherapy. The farmers were autonomous in the choice of CAVM and did not rely on the advice of the veterinarians.

Abstract: The objective of this study was to evaluate the effects of feeding a combination of chicory-plantain silage and supplementing Se-yeast on the response of early-lactating ewes to induce subclinical mastitis. Polypay ewes were fed either chicory-plantain si-lage or grass silage and supplemented with 3.6 mg Se-yeast /ewe/day for approximately 2 months prior to the intramammary infection (IMI) by infusing Strep. uberis into both glands. The ewes had a typical subclinical mastitis response with an 8-fold in-crease in milk somatic cells within 24h post-IMI, a decrease in milk yield, and changes in all milk components measured. The ewes experienced a mild systemic inflammation post-IMI as determined by an increase in rectal temperature and decrease in feed and water intake and, in blood, by an increase in concentration of ceruloplasmin, hapto-globin, and myeloperoxidase and decrease of paraoxonase, Zn, advanced oxidation protein products, and hematocrit with no effect on pro-inflammatory cytokines. No effect of silage type or Se-supplementation was detected in response to IMI. In sum-mary, the subclinical mastitis model used was effective in mounting an inflammatory response, although this was mild; however, feeding chicory-plantain silage and sup-plementing Se-yeast had no significant effect on the response of ewes to mammary infection.

Abstract: Gut microbiota composition plays a crucial role in host health and may be influenced by age and disease conditions. This study investigated the gut microbiota diversity of 175 dogs across three age groups (Junior (20–46 months), Adult (47–92 months), and Senior (93–168 months), and examined the impact of osteoarthritis on microbial composition. Alpha diversity analysis using the Shannon and Chao1 indices showed no statistically significant differences (P > 0.05) among age groups or between healthy and osteoarthritic dogs, suggesting stable microbial diversity across life stages and health conditions. Beta diversity analysis based on Bray-Curtis dissimilarity indices demonstrated substantial overlap in gut microbiota composition across age groups, with no significant clustering observed (P > 0.05). This indicates that aging and osteoarthritis do not induce significant shifts in microbial beta diversity, although high inter-individual variability was noted. Linear Discriminant Analysis (LDA) Effect Size (LEfSe) analysis identified distinct bacterial taxa associated with different age groups. Linear Discriminant Analysis (LDA) Effect Size (LEfSe) analysis identified distinct bacterial taxa associated with different age groups. Junior dogs exhibited enrichment in Blautia, Erysipelotrichaceae, and Clostridium, while Adult dogs were characterized by higher abundances of Prevotella, Streptococcus, and Ruminococcaceae. Senior dogs had increased representation of Prevotella and Ruminococcus. In osteoarthritic dogs, Peptococcus, Peptostreptococcus, Clostridiaceae, and Coprobacillus were significantly enriched, suggesting potential microbiota shifts associated with osteoarthritis. Overall, these findings indicate that while gut microbiota diversity remains stable across different life stages, specific bacterial taxa were differentially enriched in relation to age and osteoarthritis. This study enhances our understanding of gut microbiota dynamics in dogs and provides insights into potential age- and disease-related microbial signatures.

Abstract: Dictyocaulosis is a parasitic disease affecting ungulate species, including red deer (Cervus elaphus). Dictyocaulus genus consist of nine species but only four are reported to infect red deer. The disease is characterized by respiratory tract infection, particularly in lungs, bronchi and bronchioles, causing inflammatory and hemorrhagic microscopic lesions but also emphysema and edema. Biological cycle consists of a female that oviposits larvae eggs in the bronchi and trachea to be expelled to the exterior by coughing and releasing the L1 in the environment. In this study 106 adult red deer were collected from seven locations in Extremadura (Spain). Eight positive lungs were primarily assessed by morphological identification, leading to a mean intensity of 13.25 adult worms/infected lung, but globally descending to an average of 1.78 adults/sampled lung. The presence of adult worms in the upper and middle respiratory tract was confirmed by anatomopathological analysis. Molecular identification was made by sequencing the COI gene. As a result, we have detected the presence of three genetic groups supported by significant subdivision using ɸST measure but D. cervi and D. viviparus showing its respective matrilineal ancestry while D. eckerti and D. cervi showing matrilineal sharing. Consequently, introgression between these two species was suggested. D. viviparus has been identified in the same Spanish region on the basis of morphological characters, but D. cervi and D. eckerti were reported for the first time in the explored geographic area.

Abstract: The presence of dichotomizing neurons in the dorsal root ganglia (DRG) of cattle, innervating both the reticulum and the withers, may indicate a pre-spinal convergence of visceral and cutaneous sensory information. This anatomical feature could be the underlying basis for the cutaneous allodynia observed in traumatic reticuloperitonitis, also known as the "Kalchschmidt pain test." In two anesthetized calves, two retrograde fluorescent tracers, Fast Blue (FB, affinity for cytoplasm) and Diamidino Yellow (DY, affinity for nucleus), were injected into the reticulum and skin of the withers, respectively. At the end of the experimental period, the calves were deeply anesthetized and then euthanatized. The thoracic (T1-T8) DRG were collected and processed to obtain cryosections which were examined on a fluorescent microscope. A large number of neurons localized, especially in the T7 DRG, presented nuclei labeled with DY. On the contrary, only a few neurons localized exclusively in T6 and T7 DRG presented the cytoplasm labeled with FB. No neurons displayed FB and DY simultaneously within the cytoplasm and nucleus, respectively. The absence of double-labeled DRG neurons suggested the involvement of higher integration centers which integrate the afferent information to coordinate respiratory movements of the diaphragm, intercostal muscles and larynx

Abstract: Prion diseases are typically attributed to the accumulation of protease-resistant prion protein (PrPSc), yet growing evidence indicates that alternative misfolded PrP conformers and inflammatory factors may also drive neurodegeneration. Whether bac-terial lipopolysaccharide (LPS) can independently generate or exacerbate prion-like pathology in the absence of classical PrPSc remains unclear. This study aimed to determine if recombinant moPrPRes, produced by incubating normal mouse PrPC with LPS, induces prion-like disease in wild-type FVB/N mice, whether LPS alone triggers neurodegen-eration, and how co-administration of LPS influences moPrPRes and RML prion pathology. FVB/N mice were randomized into six subcutaneous treatment groups: saline, LPS, moPrPRes, moPrPRes+LPS, RML, or RML+LPS. Animals were monitored for survival, clinical signs, and body weight. Brains were assessed histologically and biochemically for spongiform changes, astrogliosis, and protease-resistant PrP. Subcutaneous moPrPRes induced a distinctive encephalopathy, with 20% mortality by 200 days post-inoculation (dpi), rising to 60% by study’s end, despite undetectable PrPSc. Chronic LPS infusion alone caused an Alzheimer’s-like pathology (~40% mortality). Co-administration of moPrPRes with LPS resulted in 30% mortality by 200 dpi and 50% survival at 750 dpi. Keywords: keyword 1; keyword 2; keyword 3 (List three to ten pertinent keywords specific to the article yet reasonably common within the subject discipline.) Notably, LPS strongly synergized with RML, accelerating disease onset, intensifying PrP deposition, and ex-acerbating spongiform changes compared to RML alone. Instead, misfolded prion con-formers and endotoxin-driven inflammation can independently or synergistically pro-mote neuropathology. Targeting inflammatory pathways and subclinical prion con-formers may thus provide new therapeutic avenues for prion-like disorders.

Abstract: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the zoonotic virus responsible for the COVID-19 pandemic, has caused global health and economic dis-ruption. American mink (Neovison vison) are highly susceptible to SARS-CoV-2 and capable of transmitting it to both mink and humans. We previously reported the first detection of SARS-CoV-2 in feral mink, with two positive cases among 13 animals in the upper courses of two rivers in the Valencian Community, eastern Spain. Here, we expand that study with 60 additional feral mink sampled from November 2020 to May 2022. Four new positives were identified using a two-step RT-PCR assay on necropsy samples including nasal and rectal swabs, lung tissue, lymph nodes, and fetuses from three pregnant females. In total, six of 73 mink tested positive, all with low viral loads. Sanger sequencing confirmed infection and revealed clustering with the B.1.177 and Alpha variants. Body weight and reproductive status analyses indicated seasonal breeding and high population turnover, consistent with other wild mink populations. These findings suggest limited SARS-CoV-2 circulation in feral mink in this region, but underscore the importance of ongoing wildlife surveillance in support of One Health strategies.

Abstract: Background: Early gut microbiome development is critical for neonatal health, and its dysbiosis may impact long-term animal productivity. This study examined the effects of parenteral Ceftiofur Crystalline Free Acid (CCFA) on the composition and diversity of the neonatal lamb fecal microbiome. Additionally, the emergence of antimicrobial resistance genes associated with CCFA exposure was investigated. Methods: Sixteen healthy neonatal lambs were randomly assigned to CCFA-treated (n = 8) or control (n = 8) groups. Fecal samples were collected on days 0, 7, 14, 28, and 56. Genomic DNA was extracted and sequenced using the Illumina MiSeq platform. Microbial composition was analyzed using the MG-RAST pipeline with the RefSeq database. Results: There were distinct microbial populations in the CCFA-treated lambs compared to the control group at each time point, with a highly significant decrease in alpha and beta diversity. The CCFA treatment showed a reduction in several key microbial taxa during nursing, but these differences were diminished by day 56. Unlike the control group, CCFA-treated lambs had core microbes potentially carrying multiple antibiotic resistance genes, including those for beta-lactam, fosfomycin, methicillin, and multidrug resistance. Conclusion: The early sheep fecal microbiome demonstrated resilience, repopulating after CCFA-induced perturbation despite a temporary reduction in key taxa during the nursing period. This highlights the microbiota's stability following a short-course antibiotic challenge. However, the transient disruption suggests potential negative impacts of antibiotics on the early gut microbiome. Notably, CCFA resistance persisted, raising concerns about its possible spread to the surrounding environment.

Abstract: Heat Shock Protein Beta-1 (HSPB1), a molecular chaperone crucial for celluar response and proteostasis, exhibits evolutionary conservation woth potential lineage-specific adaptations in placental mammals, warranting detailed comparative genomic investigation. The study investigated the characteristics, evolutionary links, motifs, secondary structure, and genetic organization of Heat Shock Protein Beta-1 (HSPB1) protein across twelve distinct mammals. Significant sequence conservation was identified using multiple sequence alignments (MSA), with over 70% identity in specific areas among the chosen organisms. Physiochemical analysis revealed that all species’ protein sequences exhibited an acidic nature, while instability indices indicated inherent protein instability. The GRAVY analysis referred to hydrophilic properties, while the aliphatic index showed heat stability. Phylogenetic analysis revealed five distinct clades, corresponding to major placental mammals’ groups (e.g. Homo sapiens, Bos Taurus), which underscores deep evolutionary divergences and conserved stress-response adaptations across lineages. Motif analysis revealed distinctive patterns in several species, and InterProScan results revealed membership in the "Homologous superfamily HSP20_like_Chapserson" family. An examination of the genetic organization indicated differences among organisms in the upstream, downstream, intron, and CDS regions, and the presence of conserved regions suggested their identity and similarity matrices. The current study conducted a computational approach and supporting evidence that HSPB1 is a novel heat shock responsive protein identified in placental mammals The current study findings provide a foundational framework delving into HSPB1 evolutionary and lineage-specific diversification, offering valuable insights into stress adaptation mechanisms and their implications for biomedical or evolutionary studies in mammals.

Abstract: The growing human population increases the need for food, beyond what terrestrial sources can provide. This boosts aquaculture demand for molluscs, fish, and crustaceans. Molluscs are popular for their nutritional benefits, making them a profitable industry. Despite a 3% annual growth in mollusc populations, recent high mortality rates and population losses due to poor feeding practices and water pollution have made them more disease prone. Limited treatment options exist for mollusc diseases in aquaculture systems. Hence, developing rapid, sensitive, and cost-effective diagnostic tools for field use is essential to identify and prevent infections promptly. Recently developed isothermal nucleic acid amplification technologies, like loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA), offer rapid results within an hour. This review examines these isothermal diagnostic techniques for mollusc pathogens and their potential for field application.

Abstract: The aim of this study was to determine, through meta-analysis, the effects of malic acid/malate supplementation on ruminal and blood parameters and diet digestibility in cattle. The effect of malic acid/malate addition was evaluated using the effect size (ES) method. Two sensitivity analyses were performed: subgroup analysis and meta-regression. The subgroups were defined as follows: “acid,” representing animals supplemented with malic acid, and “salt,” representing animals supplemented with malate. Diet-related covariates were included in the meta-regression analysis. Overall, malic acid (MAC) supplementation did not significantly affect rumen pH (ES = 0.310, P = 0.17), but subgroup analysis showed that malate increased pH (ES = 1.420, P < 0.01). MAC increased rumen propionate (ES = 0.560, P < 0.01) and total volatile fatty acids (VFAs; ES = 0.508, P = 0.03), while reducing the acetate-to-propionate ratio (P < 0.01). Starch and NDF intake were significant covariates affecting pH and VFA-related variables. MAC improved total-tract digestibility of dry matter (DM; ES = 0.547, P ≤ 0.05), crude protein (CP; ES = 0.422, P ≤ 0.05), and acid detergent fiber (ADF; ES = 0.635, P ≤ 0.05). It increased glucose levels (ES = 0.170, P = 0.05) and reduced NEFA (ES = -0.404, P = 0.03). In conclusion, MAC effects were influenced by its chemical form, improving rumen pH, CP, NDF, and ADF digestibility. MAC increased VFAs, particularly propionate, lowered the acetate-to-propionate ratio, raised blood glucose, and reduced NEFA. Diet-related covariates were important to explain the between-study heterogeneity.

Abstract: Background/Objectives: White-tailed deer (Odocoileus virginianus) (WTD) play a central role at the human-livestock-wildlife interface, given their contribution in the spread of diseases, that can affect livestock. These include a variety of both bacterial, viral and prion diseases with significant economic impact. Given the implications for WTD as potential reservoirs for a variety of diseases, methods for prevention and disease control in WTD are an important consideration. Methods: Using commercial livestock vaccines against bovine viral diarrhea virus (BVDV), in killed and modified live formulations, we test the ability of WTD to develop humoral and cellular immune responses following vaccination. Results: We demonstrate that similar to cattle, WTD develop humoral immune responses to both killed and modified live formulation. While we were unable to detect cell-mediated immune responses, the assay used in this manuscript demonstrate that WTD can produce IFN-gamma in response to stimulation. Conclusions: While we were unable to detect cell-mediated immune responses, the assay used in this manuscript demonstrate that WTD can produce IFN-gamma in response to stimulation.

Abstract: Tongue-nibbling is a rare and previously undocumented affiliative behaviour in free-ranging killer whales (Orcinus orca), known until now only from individuals under human care. This study presents the first recorded observation of tongue-nibbling between two wild killer whales in the Kvænangen fjords, Norway. The interaction, captured opportunistically by citizen scientists during a snorkelling expedition, lasted nearly two minutes and involved repeated episodes of gentle, face-to-face oral contact. This behaviour closely resembles sequences observed and described in detail in zoological settings, suggesting it forms part of the species’ natural social repertoire. The observation also supports the interpretation of tongue-nibbling as a socially affiliative behaviour, likely involved in reinforcing social bonds, particularly among juveniles. The prolonged maintenance of this interaction in managed populations originating from geographically distinct Atlantic and Pacific lineages further indicates its behavioural conservation across contexts. This finding underscores the importance of underwater ethological observation for capturing cryptic social behaviours in cetaceans, and illustrates the value of integrating citizen science with systematic behavioural documentation. The study also reinforces the relevance of managed populations in ethological research and highlights the ethical need for carefully regulated wildlife interaction protocols in marine tourism.

Abstract: In the context of increasing urbanisation, the question arises as to whether urban en-vironments can provide honeybee colonies with floral resources comparable to those available in rural areas. The present study sought to evaluate the impact of land cover on nectar collection by bees in urban and rural apiaries. To this end, changes in the mass of 10 hives, located in five urban–rural site pairs, were monitored over two years (2021–2022) to assess nectar yield, weight loss, and the number of foraging days. The 3 km surroundings of each apiary were analysed using Sentinel-2 satellite imagery from the S2GLC-PL (National Satellite Information System 2025). The analysis identified eight distinct land cover classes: Anthropogenic, Agricultural, Broad-leaved Forest, Conif-erous Forest, Grassland, Shrubs, Wetlands, and Water Bodies. The findings revealed no statistically significant variation in the total nectar collected between urban and rural colonies (72.9 kg vs. 64.5 kg; p > 0.6). However, urban colonies exhibited a significantly higher number of foraging days (67 vs. 56). No significant correlations were identified between specific land cover types and nectar yield. Principal component analysis (PCA) and clustering revealed distinct landscape gradients, yet these did not influence nectar collection. The findings of this study indicate that diverse urban environments have the capacity to support beekeeping to a similar extent as rural areas, and may even have superior conditions, provided that the continuity and diversity of nectar plants is maintained.

Abstract: Podoplanin (PDPN) is a highly glycosylated type I transmembrane protein. PDPN expression is observed in various normal tissues, including lymphatic endothelial cells, kidney podocytes, and type I alveolar epithelial cells in the lungs. Monoclonal antibodies (mAbs) targeting PDPN across different animal species have facilitated the identification of PDPN-positive cells. To date, we have developed anti-PDPN mAbs for over 20 species. These antibodies suit various applications, including flow cytometry, immunoblotting, and immunohistochemistry. In this study, we generated an anti-hippopotamus PDPN (hipPDPN) mAb, PMab-322 (mouse IgG2a, kappa), using the Cell-Based Immunization and Screening (CBIS) method. PMab-322 exhibited strong reactivity to hipPDPN-overexpressed Chinese hamster ovary-K1 (CHO/hipPDPN) cells and demonstrated moderate affinity (KD: 4.4 × 10⁻⁸ M) in a flow cytometry-based measurement. PMab-322 specifically recognizes hipPDPN but does not cross-react with PDPN from 23 other species. Furthermore, PMab-322 successfully detected hipPDPN in both immunoblotting and immunohistochemistry. These findings highlight the potential of PMab-322 for pathological analyses of hippopotamus-derived tissues.

Abstract: Most domesticated horse breeds along with wild equid species (zebras and asses and Przewalski’s Horse) make use of three standard gaits, the walk, trot, and gallop (or canter). Specialized horse breeds, however, such as the Tennessee Walker, Missouri Fox Trotter, American Saddlebred, Standardbred, Rocky Mountain Horse, Icelandic, Mangalarga Marchador, and Paso horses of South America are able to employ alternative lateral gaits including the running walk, rack, fox trot, broken pace, and hard pace. How these gaits arose and spread throughout the world is still something of a mystery, as is what exact benefits they provided to human riders. This brief survey provides further information that has come to light on the presence and use of such alternative lateral horse gaits in art and history subsequent to the author’s previous publications.

Abstract: This study examines the reproductive outcomes of Lacaune crossbred ewes and hoggets under intensive production systems, focusing on vaginal prolapse and hydrometra associated with flaws in estrus synchronization (E.S.) protocols. Data from multiple farms were combined for analysis due to the absence of significant variation at the farm level. The findings revealed a strong association between vaginal prolapse, parity, and litter size, with hoggets carrying multiple fetuses facing the highest risk (p &lt; 0.0001). This highlights the need to reconsider equine chorionic gonadotropin (eCG) administration in hoggets, as it increases the likelihood of multiple pregnancies and, consequently, prolapse. Additionally, a progressive rise in hydrometra prevalence was observed with repeated synchronization cycles in ewes, increasing from 0.51% after the third treatment to 12.33% after the fourth (p &lt; 0.0001). Notably, in this study, the four synchronization cycles were applied over a relatively short period (7.22 ± 1.64 months), further supporting concerns that excessive hormonal treatments within a compressed timeframe exacerbate reproductive dysfunction. This pattern confirms that prolonged progesterone exposure can impair uterine function, leading to fluid retention and hydrometra, as previously reported. To mitigate these risks, adjustments in synchronization protocols—such as extending the interval between successive treatments—are necessary to safeguard reproductive health and enhance animal welfare. These findings underscore the importance of optimizing estrus synchronization strategies to balance productivity with the well-being of sheep in intensive farming systems.

Abstract: This study investigated the feasibility of incorporating Chenopodium album L (CAL) into ruminant feed ingredients by evaluating the effects of harvest time and substitution levels on in vitro rumen fermentation. In the first phase, a sole-substrate experiment was conducted using CAL harvested from June to August, analyzing its chemical composition and total saponin content. The impact of harvest time on fermentation parameters was assessed with CAL as the sole substrate. The second phase involved a mixed-substrate experiment using an early-fattening Hanwoo diet (30% rice straw and 70% concentrate), where increasing proportions of CAL (Control: 0%, T1: 5%, T2: 10%, T3: 15%, and T4: 20%) replaced rice straw. Seasonal variations in CAL composition influenced fermentation characteristics, with July-harvested CAL exhibiting higher fermentability, while August-harvested CAL had lower fermentability. However, August-harvested CAL was selected for the second experiment due to its greater availability. We hypothesized that saponins in CAL contribute to methane reduction. Supplementation with 15% of CAL significantly reduced methane production per gram of digested substrate (p &lt; 0.05), likely due to differences in crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and saponin content. However, despite having the lowest fiber content, T4 (20% CAL) exhibited the lowest in vitro dry matter digestibility (IVDMD), suggesting that factors such as saponins, CAL’s chemical composition, or microbial shifts may have hindered digestibility. Fermentation characteristics further revealed that the acetate-to-propionate (A/P) ratio decreased with increasing CAL levels, with T4 showing the lowest ratio (1.55 at 72 hours), confirming a shift toward propionate-based fermentation. Notably, T2 (10% CAL) optimized fermentation efficiency, producing the highest total volatile fatty acid (VFA) concentration at 24 hours (98.28 mM). These findings highlight the potential of CAL as a functional feed ingredient, with moderate substitution levels (10–15%) enhancing fermentation efficiency while reducing methane production.

Abstract: Despite the known impacts of weaning on animal health, the underlying molecular mechanisms remain unclear, particularly how psychological and nutritional stress differentially affect gut health and immune function over time. This study hypothesized that early weaning exerts distinct short- and long-term effects on lamb stress physiology, immunity, and gut health, mediated by specific molecular pathways. Methods: Twelve pairs of full-sibling male Hu sheep lambs were assigned to control (CON) or early-weaned (EW) groups. Plasma stress/immune markers were dynamically monitored, and intestinal morphology, antioxidant capacity, apoptosis, and transcriptomic profiles were analyzed at 5- and 28-days post-weaning. Results: Early weaning triggered transient psychological stress, elevating hypothalamic-pituitary-adrenal (HPA) axis hormones (cortisol, catecholamines) and inflammatory cytokines (TNF-α) within 1 day (P < 0.05); however, stress responses were transient and recovered by day 7. Sustained intestinal remodeling was observed in EW lambs, featuring reduced ileal villus height, increased crypt depth (P < 0.05), and oxidative damage (MDA levels doubled vs. CON; P < 0.01). Compensatory epithelial adaptation included increased crypt depth but paradoxically reduced villus tip apoptosis (decreased TUNEL+ cells), suggesting stress-driven suppression of programmed cell death to preserve epithelial integrity. Transcriptome analysis revealed significant changes in gene expression related to immune function, fat digestion, and metabolism. Key DEGs included APOA4, linked to lipid transport adaptation; NOS2, associated with nitric oxide-mediated immune-metabolic crosstalk; and mitochondrial gene COX1, reflecting energy metabolism dysregulation. Protein-protein interaction analysis revealed NOS2 as a hub gene interacting with IDO1 and CXCL11, connecting oxidative stress to immune cell recruitment. Conclusion: These findings underscore the intricate interplay between metabolic stress, immune function, and gut health during early weaning. Early weaning exerts minimal lasting psychological stress but drives persistent gut dysfunction through nutritional-metabolic reprogramming. This study elucidates the molecular mechanisms driving these changes. Future studies should address strategies to mitigate oxidative stress and optimize lipid utilization during the weaning transition.

Abstract: Despite recent advances in biomedical research, translating preclinical findings into effective therapies remains a major challenge—particularly for complex diseases. Spontaneous diseases in companion animals, especially dogs, offer a powerful yet underutilized bridge to human medicine. Naturally occurring cancers, neurodegenerative disorders, and cardiovascular, renal, and ocular diseases in dogs closely resemble their human counterparts in pathophysiology, treatment response, and environmental exposure. These models allow for the evaluation of novel therapies, including immunotherapies and gene-based treatments, in immunologically relevant systems. Integrating patient-derived organoids and physiologically based pharmacokinetic modeling further enhances mechanistic understanding and translational accuracy. To fully leverage this potential, investment in infrastructure, biobanking, and interdisciplinary training is essential. As One Health gains momentum, spontaneous canine models emerge as scientifically robust and ethically sound tools for more predictive, cross-species drug development.