Veterinary Research Forum

Abstract Progress in developmental biology has advanced rapidly as the field has evolved. Recently, the generation of miniature three-dimensional organs, known as organoids, has transformed in vitro organism modeling. While organoids are well established in mammalian regenerative medicine, their application in poultry science is still limited. This review covers avian developmental and stem cell biology as well as organoid development across various avian species and organs. It highlights a major milestone in avian organoid technology, summarizes current methods and the derivation of organoid types—including skeletal muscle, enteroid, intestinal, respiratory and reproductive organoids—and discusses their applications in poultry and veterinary science, including infectious diseases, host-pathogen interactions, development, nutrition and toxicology. It also discusses the emergence of avian organoid technology platforms and future perspectives. Overall, this innovative technology offers significant potential for poultry and veterinary research, advancing disease modeling and precision health, aligning with the One Health approach that links animal and human health.

Abstract Pasteurella multocida and Mannheimia haemolytica are significant bacteria of respiratory tract infections in cattle. Identifying whether these bacteria are commensal or pathogenic is crucial for understanding their role in predisposing calves to respiratory tract infections. This study aimed to determine the prevalence and pathogenic characteristics of P. multocida and M. haemolytica in nasal swab samples of clinically healthy calves in Konya, Türkiye, and to assess antibiotic resistance profiles. Using conventional culture methods, five samples (1.67%) from four different farms were positive for P. multocida and three samples (1.00%) were positive for M. haemolytica. The PCR of nasal swab samples yielded P. multocida positivity in 17 (5.67%) samples and M. haemolytica positivity in 13 (4.34%), including all culture-positive samples. While all P. multocida isolates were atypical for the capsule, 17.65% of the PCR-positive samples were L2, 70.59% L3A, and 11.76% L8 serotypes. The ompA, omp87, hghA, and tbpA genes were the most prevalent, while the presence of other virulence genes varied. High rates of APX (100%) and S (80.00%) resistance were observed among the isolates. The rates of serotypes A1 and A6 in M. haemolytica PCR-positive samples were 53.85 and 46.15%, respectively. The ssa-1 gene was detected in 33.33% of the isolates. Moderate resistance to SXT, S, and N (66.67%) was recorded. The findings revealed the presence of P. multocida and M. haemolytica with various virulence characteristics and antimicrobial resistance profiles in the nasal microbiota of healthy calves providing novel insights that could inform improved herd management, disease control, and treatment strategies.

Abstract Subclinical endometritis (SCE), driven uterine dysbiosis, impairs fertility by reduced conception, embryonic survival and overall reproductive efficiency. The ovarian sequelae of SCE in Bos indicus remain poorly defined. Tharparkar cows (n = 20) were enrolled and monitored across one estrous cycle using transrectal B-mode and Doppler ultrasonography. Animals were classified as SCE (n = 10) or healthy (n = 10) based on endometrial polymorphonuclear neutrophil proportions (> 5.00%), a threshold justified by breed-specific postpartum uterine adaptation in B. indicus. Polymorphonuclear neutrophils were significantly higher in the SCE group (6.80 ± 0.24% vs. 3.30 ± 0.21%). SCE cows exhibited reduced medium and total follicle numbers and slower dominant follicle growth (0.89 ± 0.05 vs. 1.02 ± 0.03 mm per day). Mean corpus luteum (CL) pixel area was consistently lower in the SCE group throughout the luteal phase. The CL vascularity indices derived from color Doppler mode (red = toward, blue = away from transducer) were reduced (e.g., day three perfusion: 24.94 ± 2.75% vs. 17.71 ± 2.34%). Serum progesterone was lower in SCE cows and strongly correlated with CL size (Pearson's correlation coefficient [r] = 0.89; 95.00% confidence interval, [CI] = 0.84 - 0.92) and perfusion (r = 0.50, 95.00% CI 0.35 - 0.62). In conclusion, SCE in B. indicus compromised follicular dynamics, early CL development, vascularization and steroidogenesis. Pixel-derived Doppler indices provided robust quantitative markers for early detection and targeted management of SCE.

Abstract Salmonella enterica serovar Typhimurium is a major pathogen associated with poultry. This study evaluates the efficacy of a bacteriophage cocktail, comprising SEPL01 (Siphovirus) and SEPL13 and SEPL20 (Myoviruses), in controlling Salmonella typhimurium infection in poultry. For current study, 168, day-old indigenous chicks were selected and divided into five groups: negative control, positive control, prophylactic, 3-days, delayed post challenge and 6-hr post-challenge groups. For experiment, birds were orally dosed with 1.00 × 10⁵ colony-forming unit mL^-1 of S. typhimurium on day four of trial. Test groups were administered a bacteriophage cocktail (1.00 × 10⁷ PFU mL^-1 [plaque-forming unit per mL]) orally, intra-nasally, or through drinkers. Quantitative assessment of bacteria loads was done by performing dilution plate counts using xylose lysine deoxycholate agar and the log reduction determined. The positive group showed a natural progression of bacterial infection with bacterial counts increasing from log10 4.82 at 3rd day post challenge to log₁₀ 5.45 (7th day), and log₁₀ 5.20 (14^th day). The prophylactic group recorded the greatest level of the bacterial decrease; the log₁₀ reduction were 1.94 (3^rd day), 1.73 (7^th day) and 1.22 (14th day) after the oral gavage. For drinking water administration, values were 1.84, 1.66 and 1.12 for log reduction, whereas, for nasal spray, the values were 1.17, 0.88 and 0.41 on 3^rd, 7^th and 14^th day, respectively. 6-hr post-challenge group had a moderate reduction, (1.63, 1.37, 1.22 through oral gavage) while the 3-day post-challenge group possessed slightly less reduction (1.56, 1.24, 0.92). The lowest bacterial loads were recorded when bacteriophages were given via oral gavage and drinking water.

Abstract A sound knowledge of follicular dynamics needs to be better understood in any species. However, there remains a need for comprehensive histomorphometrical quantification across all four seasons, incorporating both ovaries in dromedary camel is crucial prerequisite. Present study aimed to quantify histomorphometrical variations in follicles across seasons of a year. For this purpose, from 36 (4-7 years old) apparently healthy and no pregnant dromedary female camels (three in each month of a year) right and left ovaries were collected, processed through paraffin embedding technique, semiserially cut at 5.00 - 7.00 µm and stained with Hematoxylin and Eosin method. Through all the seasons, the highest counts were consistently recorded for primordial follicles, particularly in the right ovary. Primary and secondary follicles were stand in second record. Graafian follicles were detected in some animals, likewise reaching their maximum frequency in the winter (January). Atretic follicles were observed through all seasons. No significant differences were observed between the left and right ovaries for these follicular categories. The results indicated a general increasing trend in follicle numbers with advancing age. At 4 and 6.5 years of age, the mean follicle counts were increased with less sharpness, but at 7 years of age, the highest value was recorded. In conclusion, our results, confirm that while early folliculogenesis in this animal appears season-invariant, late-stage maturation and follicular atresia are strongly modulated by environmental and seasonal factors. These findings contribute to the optimizing reproductive management strategies, particularly in aligning breeding efforts with periods of enhanced ovarian activity.

Abstract Diazinon (DZN) is an insecticide with a wide range of applications in developing countries, which can cause kidney toxicity through oxidative stress. Biebersteinia multifida DC (BM) is a medicinal plant native to Iran with reported anti-oxidant properties. This study examined the effect of BM root extract and DZN on extracellular signal-regulated kinase (ERK) and phosphorylated-ERK (p-ERK) expression levels and the activity of oxidative stress factors in a rat kidney. In this experimental study, 24 male rats were randomly divided into four groups, including control, DZN (40.00 mg kg^-1), BM (150 mg kg^-1), and DZN + BM. Treatments were administered orally once daily for 6 weeks. Kidney tissues were collected for biochemical assays, western blot analysis, and histological evaluation. Data were analyzed using SPSS Software. The DZN exposure induced marked renal injury, characterized by reduced glomerular mesangial matrix, thinning of the glomerular basement membrane, decreased laminin expression, and down-regulation of ERK and p-ERK proteins. Also, DZN altered anti-oxidant enzymes activities. In contrast, BM treatment improved histological parameters, restored laminin expression, and increased ERK and p-ERK levels. The BM also modulated oxidative stress markers by enhancing anti-oxidant enzymes activities and reducing oxidative imbalance. Biebersteinia multifida may exert protective effects against DZN-induced renal injury through improvement of glomerular structure, modulation of ERK signaling, and attenuation of oxidative stress, suggesting its potential nephroprotective properties.

Abstract Escherichia coli is one of the most important pathogens with a multi-drug resistance pattern in animal-origin food, especially dairy products. This study aimed to assess the prevalence of E. coli in raw milk and traditional dairy products, including 60 raw milk, 60 traditional fresh cheese, and 60 traditional butter, and to characterize the antibiotic resistance profiles, biofilm-forming capacity, and virulence genes of the isolates. Escherichia coli was isolated from 21.12% of all samples, including 26.67% of raw milk, 16.67% of cheese, and 20.00% of butter. There was no statistically significant difference between the groups. All isolates were resistant to ampicillin, and none were resistant to aztreonam, with 36.84% of isolates identified as the multi-drug resistant. In addition, 60.52, 26.31, and 13.15% of isolates produced strong, moderate, and weak biofilm, respectively. The frequencies of stx1, stx2, csgA, and rfbE genes were 13.15, 18.42, 71.05, and 68.42%, respectively, and the differences between the frequencies were significant. Raw milk and traditional dairy products are potential sources of pathogenic E. coli, and continuous monitoring of these food products is required to ensure public health.

Abstract The rising demand for natural wound dressings has spotlighted bacterial nanocellulose (BNC), produced by Komagataeibacter xylinus, for its biocompatibility, biodegradability, and high crystallinity. Combined with honey, renowned for antimicrobial, anti-inflammatory, and regenerative properties, this composite offers enhanced therapeutic potential. This study evaluated the efficacy of BNC/honey composites in healing excisional wounds in mice. Twenty-four mice were divided into four groups, including untreated control, honey-only, BNC-only, and BNC/honey composite. An 8.00-mm full-thickness wound was created dorsally, and healing was monitored over 14 days. Planimetry showed accelerated wound contraction in the composite group. Histopathology (days seven and 14) revealed superior tissue regeneration, increased angiogenesis, and fibroblast proliferation. Biochemical assays demonstrated significantly elevated total anti-oxidant capacity and glutathione peroxidase activity, alongside reduced oxidative stress markers (total oxidant status and malondialdehyde) in the composite group. Hydroxy-proline levels, indicating collagen synthesis, were also the highest in this group. Collectively, the BNC/honey composite markedly enhanced wound healing by promoting collagen deposition, reducing inflammation, and boosting anti-oxidant defense. These findings position the BNC/honey composite as a highly promising, natural biomaterial for advanced wound care with strong translational potential in clinical settings.

Abstract This study comparatively evaluated the protective effects of nanocurcumin and black seed against bacterial lipopolysaccharide (LPS)-induced acute arthritis in pigeons, compared with the standard nonsteroidal anti-inflammatory drug diclofenac. Thirty-five pigeons were divided into five groups: sham control (T1), LPS-induced arthritis control (T2), and treatment groups receiving diclofenac (T3), black seed (T4), or nanocurcumin (T5) after LPS challenge. Arthritis was induced by intra-articular LPS injection into the right hock joint. At 48 hours post-injection, synovial fluid was collected for pro-inflammatory cytokine measurement, serum epinephrine and corticosterone levels were assayed, and joint tissue was histopathologically evaluated. LPS injection (T2) significantly increased synovial pathology severity (hyperplasia, inflammation) versus the sham group, with congestion, reactive fibrosis, mononuclear inflammatory cell aggregation, dense adipocyte accumulation, and chondrocyte hypertrophy. Group T4 showed a severe inflammatory reaction, while groups T3 and T5 had a total score of 6. Systemically, LPS significantly elevated serum epinephrine and corticosterone; diclofenac produced the greatest reduction in both compared with the natural supplements. In synovial fluid, the positive control had the highest tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) concentrations. Diclofenac showed the strongest TNF-α suppression, while both black seed and nanocurcumin significantly reduced TNF-α and IL-6 versus the untreated group. Nanocurcumin significantly reduced corticosterone compared with black seed. Diclofenac exhibited the most potent anti-inflammatory effect; however, both nanocurcumin and black seed provided significant therapeutic benefits in mitigating LPS-induced acute arthritis, suggesting their potential as viable natural adjuncts in avian inflammatory disease management, particularly given the toxicity profile of nonsteroidal anti-inflammatory drugs.

Abstract Cutaneous squamous cell carcinoma (CSCC) is a clinically significant skin neoplasm in dogs, typically arising in areas exposed to chronic ultraviolet light. This report described a 10-year-old intact male Pitbull dog weighing 33.00 kg that presented with a large, ulcerated, necrotic and hemorrhagic mass in the inguinal mammary region. Initial hematological evaluation revealed marked leukocytosis with segmented neutrophilia, severe toxic changes along with degenerated neutrophils observed in fine needle aspiration of the mass. Following a course of antibiotic therapy to control the severe infection, the mass was surgically excised using electrosurgery. The preoperative thoracic radiographs ruled out pulmonary metastasis. Histopathological examination confirmed the diagnosis of CSCC. Despite complete initial removal, tumor recurrence was noted seven months postoperatively. The owner declined further chemotherapy and surgical intervention. This report detailed the clinical case of a massive, CSCC located in the ventral abdominal/inguinal mammary region of a male Pitbull dog. Although CSCC is a common neoplasm in canines, this case was distinguished by its extreme size, secondary infection and atypical anatomical presentation in a male dog. The report highlighted the unique clinical challenges associated with managing an unusually severe manifestation of a common tumor and provided a comprehensive overview of the surgical, radiological and histopathological findings.