Veterinary Research Forum

Abstract Infectious bronchitis virus (IBV) is an important pathogen in the poultry industry causing avian infectious bronchitis that is, an acute but highly contagious disease affecting the upper respiratory tract, kidneys and reproductive tract. The 3rd passage of a polymerase chain reaction confirmed nephropathogenic IBV isolate was used for this study. Heat stability for 5, 10, 15, 20, and 30 min at 56.00 ˚C, pH sensitivity at pH 3.00, 7.00, 9.00, and 11.00 ultraviolet (UV) irradiation for 10, 15, 20, and 30 min, and chloroform sensitivity were studied. The IBV isolate was found to be susceptible to a temperature of 56.00 ˚C for 5 min and above, UV irradiation within 10 min, chloroform treatment and to pH 11.00 while being resistant to pH 3.00 and 9.00. The second part of the study investigated in vitro effectiveness of the disinfection potential of several commercially used disinfectants in Pakistan against the IBV isolate. For this purpose, Virkon S, Bromosept, and Beloran were employed for the virus inactivation test. Following the IBV challenge for contact time of 1, 5, 10, and 30 min, we counted the number of embryos that died after incubation. Results showed that suitable dilution of disinfectant for the recommended contact period could kill the virus. The maximum susceptibility was seen in the case of Virkon S which killed the virus in just 1 min. Thus, IBV could be killed using commercially available Virkon S, Beloran, and Bromosept after being used in recommended concentrations for recommended contact time.

Abstract Sterilization in animals serves multiple purposes, such as behavior control, performance improvement, and population management. Chemical sterilization has emerged as a promising non-surgical alternative to traditional methods. This study aimed to investigate the effects of intra-testicular injection of zinc-doped carbon dots (Zn-CDs) nanoparticles as a chemical sterilant in mature rats. Twenty-five rats were randomly divided into five groups, including a control group without injection, a sham group receiving 0.50 mL distilled water, and three treatment groups administered respectively 0.50, 2.00, and 8.00 mg kg^-1 of Zn-CDs synthesized through a hydrothermal process. Following anesthesia with ketamine and xylazine, and aseptic preparation, intra-testicular injections were administered bilaterally. At 60th day post-injections, blood samples were collected to measure serum testosterone levels using chemiluminescence immunoassay. The rats were then surgically castrated to assess sperm parameters and testicular histopathology. Testicular oxidant/anti-oxidant status was also evaluated. The results revealed a dose-dependent reduction in sperm viability, membrane integrity, and motility, accompanied by increased sperm DNA damage. The highest Zn-CDs dose caused the most significant decrease in sperm concentration, as well as severe testicular tissue damage. In addition, anti-oxidant capacity, seminiferous tubules maturation, testosterone production, and spermatogenesis declined with increasing Zn-CDs concentrations in a dose-dependent manner. These findings indicate that intra-testicular injection of Zn-CDs effectively induces infertility in mature rats and holds potential as a chemical sterilization method. With further studies to evaluate safety and efficacy, this approach could be developed as a practical solution for large-scale in situ castration, offering a non-surgical alternative for over-population control programs.

Abstract Vertebrate skeletons can be considered as a combination of apparently separate units, which has attracted the attention of comparative anatomists. The Luristan newt (Neurergus kaiseri) is one of the newt species native to Iran, inhabiting a limited area in the southern Zagros Mountain range. The present study investigated the typical morphometrical characteristics of the normal, mature, and healthy Luristan newt vertebral column using micro-computed tomography (micro-CT). For this study, five female and five male specimens of Luristan newt were utilized. The typical morphological characteristics of the vertebral column were then examined. To facilitate the description of different regions of the vertebral column, abbreviations were employed: "T" for trunk vertebrae, "S" for sacral vertebrae, "Cd-S" for caudosacral vertebrae, and "Cd" for caudal vertebrae. All parameters, including vertebral body height, vertebral body length, spinous process height, spinal canal width, and spinal canal height, exhibited significant differences throughout the vertebral column. The highest vertebral body height in both sexes was recorded in T10. The highest vertebral body length in both sexes was observed in T12. The highest spinous process height in both sexes was recorded in Cd3. The highest spinal canal width in both sexes was recorded in the atlas. The maximum spinal canal height in both sexes was also recorded in the atlas. The lowest values in all parameters were observed in the last caudal vertebra. This study presents a comprehensive description and morphometric evaluation of the vertebral column in Luristan newt with micro-CT. 

Abstract Newcastle disease (ND) is a highly contagious and severe disease that affects birds, including domestic poultry, causing significant economic losses to the poultry industry. The disease is caused by the ND virus (NDV). Despite extensive vaccination efforts against NDV, controlling the disease remains challenging, primarily due to the emergence of new genotypes. Recent attention has focused on calcium phosphate nanoparticles (CaP NPs) as promising adjuvants for vaccines. This study aimed to design and construct CaP NPs containing inactivated NDV genotype VII and evaluate their safety and humoral immunogenicity in chickens. Following virus propagation in specific-pathogen-free eggs and inactivation with formalin, CaP NPs containing inactivated NDV were prepared using in situ and adsorption methods. The NPs were characterized for shape, size, polydispersity index and surface charge. Chickens were immunized subcutaneously with CaP NPs containing inactivated NDV and the humoral immune response against NDV was assessed using HI and enzyme-linked immunosorbent assays. Results showed a significant increase in the mean antibody titer against NDV in chickens treated with both NP structures compared to control groups. No significant difference was observed between the two NP preparation methods. The safety of CaP NPs containing inactivated NDV was confirmed. However, mucosal immunization with these NPs did not yield satisfactory results indicating the need for further research. Overall, this study confirmed the positive role of CaP as an adjuvant in enhancing the humoral immune response against NDV via injection and highlighted the need for continued research on mucosal immunization with the NPs.

Abstract This study compared the effects of a dose of human chorionic gonadotropin (hCG) administration at the time of insemination on the reproductive outcome of estrus-synchronized Mongolian ewes subjected to two artificial insemination methods during the breeding season. All females were treated with a polyurethane intravaginal sponge impregnated with 45.00 mg of flurogestone acetate for 12 days, followed by an intramuscular injection of 330 IU of equine chorionic gonadotropin at sponge removal. In Experiment 1, 150 ewes were inseminated using a laparoscopic intrauterine artificial insemination method 48 hr after sponge removal. The ewes were randomly assigned to the hCG group which received 500 IU of hCG at the time of insemination, and the control group which received 1.00 mL of sterile saline solution. In Experiment 2, 85 ewes were inseminated twice at 48 and 60 hr after sponge removal using a cervical artificial insemination method. The ewes were randomly assigned to the hCG group, which received 500IU of hCG at the time of the first insemination and the control group which received 1.00 mL of sterile saline solution. The pregnancy rate in the control group was not significantly different compared to the hCG group in Experiment 1 and the pregnancy rate in the control group was significantly higher compared to the hCG group in Experiment 2. In conclusion, the administration of hCG at the time of insemination could not be recommended in ewes when implementing a fixed time artificial insemination protocol during the breeding season.

Abstract Ventricular septal defect (VSD) is a common congenital anomaly in large animals, but it is rarely documented in small ruminants. This report described a case involving a three-month-old male lamb of the Iranian Shall breed that was presented to a Veterinary Hospital of University of Tehran with nasal discharge and growth retardation. Clinical examination revealed a heart rate of 120 beats per min, a respiratory rate of 50 breaths per min, pale mucous membranes and a low-grade pansystolic murmur that was auscultated bilaterally in the thoracic region. Echocardio-graphy revealed a 10.00 mm defect between the right and left ventricles, located in the supraventricular region behind the aortic valve, along with evidence of left-to-right shunting. Imaging studies including echocardiography and radiography indicated increased cardiac volume particularly in the right ventricle. These findings were corroborated by necropsy. This case study aimed to elucidate the imaging findings associated with Ventricular septal defect in an Iranian Shall lamb.

Abstract Hepatic lipidosis (fatty liver) is a rare condition in dogs, primarily caused by improper feeding and care practices. It involves the accumulation of triacylglycerols in hepatocytes due to various toxic factors and dietary carbohydrate deficiencies. This case report describes the clinical, hematological, and pathological findings of an abandoned 8-year-old dog suffering from hepatic lipidosis that was referred to an animal shelter. The dog was unconscious, immobile, depressed, and severely obese. Pronounced abdominal distension and icteric mucous membranes were immediately noticeable during the initial examination. A blood sample was collected, and the case was referred to a veterinary hospital for diagnostic imaging. Unfortunately, before the referral could be completed, the dog suddenly died. Immediately following the death, a postmortem necropsy was performed to determine the cause. Necropsy revealed an extremely enlarged liver with a yellowish discoloration and abnormal kidneys with nodular lesions. Based on these findings, fatty liver was strongly suspected. Complete blood count and biochemical parameters, including triglycerides, cholesterol, aspartate transferase, alanine transaminase, and alkaline phosphatase, were subsequently evaluated. Complete blood count results indicated leukocytosis, thrombocytopenia, and an increase in red cell distribution width. Biochemical analyses revealed hypertriglyceridemia and elevated levels of alanine transaminase, aspartate transferase, and alkaline phosphatase. Histopathological examination confirmed severe fatty degeneration in the liver, alongside marked degenerative and necrotic changes in the kidneys. The findings of the present study contribute to the limited data on canine hepatic lipidosis and underscore the necessity of raising awareness about its clinical presentation, diagnostic markers, and histopathological characteristics.

Abstract A 4.5-year-old, nulliparous female New Zealand White Rabbit (Oryctolagus cuniculus) was presented for evaluation of a mammary mass located in right axillary mammary gland. The surgically excised mammary mass was submitted for histopathological and immunohistochemical evaluation. Histopathologically, neoplastic cells were arranged in sheets and nests of irregular sizes. The tissue was composed of amorphous eosinophilic material and necrotic cells. The neoplastic cells had round to oval nuclei with prominent nucleoli, scant basophilic cytoplasm and high mitotic activity. Cytokeratin and vimentin expressions of neoplastic cells were observed in immunohistochemical findings. Based on the microscopic characteristics and immunohisto-chemical staining, a diagnosis of a non-invasive comedocarcinoma was established. In this case, cytokeratin positivity confirmed the epithelial origin, whereas the vimentin positivity supported the presence of epithelial-mesenchymal transition and/or increased malignancy.