Veterinary Research Forum

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 describes 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 cutaneous SCC. Despite complete initial removal, tumor recurrence was noted seven months postoperatively. The owner declined further chemotherapy and surgical intervention. This report provides a comprehensive overview of the surgical, radiological, and histopathological findings of a massive cutaneous squamous cell carcinoma located in the ventral abdominal mammary region in a male Pitbull dog.

Abstract Hydronephrosis is an uncommon condition in cats and dogs, characterized by progressive dilation of the renal pelvis and subsequent atrophy of the renal parenchyma. This report described an 8-year-old spayed female domestic longhair cat diagnosed with left-sided hydronephrosis and concurrent polycystic kidney disease after comprehensive clinical, laboratory and imaging evaluation. Because the contralateral kidney appeared functionally preserved, unilateral nephrectomy was selected as the most appropriate treatment option. During surgical manipulation, however, the affected kidney unexpectedly separated completely from its attachments before vascular ligation could be performed, without evidence of hemorrhage. The procedure was completed without complication and no intraoperative or postoperative adverse events were recorded. The patient recovered uneventfully and remained stable throughout the perioperative period. To the authors’ knowledge, this report represented the first documented case in veterinary literature regarding spontaneous renal autoavulsion occurring during nephrectomy. This unusual finding underscored the severe structural fragility that could result from chronic obstructive renal disease and advanced parenchymal destruction. In addition, it suggested that renal autoavulsion might represent a previously unrecognized end-stage manifestation of longstanding hydronephrosis, particularly when associated with concurrent renal pathology such as polycystic kidney disease. This report emphasized the importance of thorough preoperative assessment, careful surgical planning and awareness of potentially extreme anatomic alterations in chronically diseased kidneys.

Abstract Testicular ischemia-reperfusion injury during testicular torsion is strongly influenced by oxidative stress caused by excessive accumulation of uncaptured reactive oxygen species. Kisspeptin-10 (Kiss-10), a biologically active fragment of kisspeptin peptide family, has demonstrated significant anti-oxidant and anti-apoptotic properties. Recent studies indicate that Kiss-10 can mitigate oxidative stress by reducing reactive oxygen species levels and enhancing the activity of endogenous anti-oxidant enzymes, such as superoxide dismutase and catalase. This study examined the effects of Kiss-10on ischemia-reperfusion injury in testicular torsion/detorsion (T/D) of male rats. Twenty male rats were divided into four groups, including the control group and three treatment groups (720° T/D, 720° T/D + 0.50 µg kg^-1 Kiss-10, and 720° T/D + 1.00 µg kg^-1 Kiss-10). After inducing 720° clockwise testicular torsion for 2 hr, sperm parameters, such as number, motility, viability, DNA damage, and hypo-osmotic test were evaluated. The results showed that 720° T/D can increase sperm DNA damage. Also, it also had negative effects on overall motility and other properties, such as viability and plasma membrane functionality. The results also showed that administration of Kiss-10to T/D rats can reduce DNA damage. It could also increase overall motility, viability, and plasma membrane functionality compared to the T/D group. Based on our results, Kiss-10 provides significant protection against acute T/D injury to the testis when administered after spermatic cord torsion in rat.

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 Scaffolds play a crucial role in tendon healing by providing structural support, promoting cell infiltration, and guiding tissue regeneration. Polycaprolactone (PCL) has been used as a polymer in biological scaffolds for several tissue engineering studies. This study aimed to investigate the effects of curcumin-loaded PCL scaffold on Achilles tendon using a tenotomy model in rats. Twenty adult male Wistar rats were randomized into two groups. In control group, tenotomy and suture placement were performed. The identical intervention followed by the implantation of curcumin-loaded PCL scaffold around the tendon stumps was performed in the treatment group. The nanofibrous PCL scaffold containing 5.00% curcumin was fabricated by electrospinning. Walking track analysis was performed weekly. Then, after 6 weeks, histopathological examination and tendon mechanical tests were performed. The weekly walking track analysis revealed a significant improvement in Achilles functional index in scaffold-treated rats from week three to six. The rate of functional improvement was remarkably slower in the control group. Histopathological examination revealed aseptic inflammation and enhanced neovascularization in the treatment group. Also, collagen arrangement and density were significantly improved in this group compared to the control samples including less regular orientation and loose organization of collagen fibers. Significant increase in mechanical properties, except for strain, was observed in the treatment group. The present study demonstrated that implantation of curcumin-loaded PCL scaffold resulted in increased fibrillar architecture, as well as improved mechanical properties and Achilles functional index in rats. To reduce the biodegradation-induced inflammation, an anti-inflammatory treatment is recommended.

Abstract Tendon healing is prolonged due to the small number of cells, poor circulation, and low metabolism. The optimal tendon healing and its complete functional recovery have always been a challenge for researchers. Silymarin possesses anti-inflammatory, anti-oxidant, analgesic, and regenerative properties. The present study aimed to investigate the effects of silymarin on healing the Achilles tendon in rats. Twenty-four male Wistar rats were divided into two groups of control and treatment. After surgical preparation, a complete transverse incision was made in the middle part of the Achilles tendon, and then a modified Kessler suture was placed. The control group received 1.00 mL normal saline for five consecutive days, and the treatment group received 50.00 mg kg^-1 of silymarin suspended in 1.00 mL normal saline for five days, orally. During the experimental period, Achilles functional index (AFI) was recorded. Six weeks after surgery, sampling was done. Histopathologically, a significant increase in the density of collagen fibers and reduction in neovascularization and inflammatory cells infiltration were observed in the treatment group. The biomechanical evaluation showed a significant increase in tensile strength of the tendon in the treatment group compared to the control group. The AFI results were concomitant with the results stated above, indicating an improvement in the AFI of rats in the treatment group. The present study results showed that oral administration of silymarin improved tissue healing indices, biomechanical properties, and functional index, leading to optimal healing of experimental Achilles tendon injury in the rat.

Abstract Chitosan bears numerous properties, such as biocompatibility, biodegradability and non-toxicity making it suitable for use in different biomedical fields. Zinc (Zn) is required for fibroblasts proliferation and collagen synthesis as essential elements of wound healing. Its nanoparticles are well known for their capability to enhance wound healing by cell adhesion and migration improvement through growth factors-mediated mechanisms. Poor blood supply and unique histological characteristics of tendon make its regeneration always slow. Also, adhesion formation between tendon and its surrounding tissues is another problem for neotendon to return to its normal structure and functional activities. In this study, a novel tubular scaffold of zinc oxide (ZnO) nanoparticles loaded chitosan has been fabricated for tendon repair. Experimental complete tenotomy of deep digital flexor tendon in a rabbit model was done and scaffolds were placed in the transected area after two ends suturing. After four and eight weeks, adhesion formation around the tendons and tissue reaction to the scaffolds were evaluated macroscopically. Inflammation, angiogenesis and collagen fibers arrangement were also analyzed in histopathological evaluations. After eight weeks, the scaffolds were absorbed completely, adhesions around the tendon were decreased and there was no sign of significant tissue reaction and/or infection in histopathological analyses. The reduced adhesion formation, improved gliding function and better histopathological characteristics suggest this scaffold application as a potential therapy in treatment of tendon acute injuries.

Abstract Tendons are frequently targets of injury in sports and work. Whether nonsteroidal anti-inflammatory drugs (NSAIDs) have beneficial effects on tendon healing is still a matter of debate. This study was conducted to evaluate effects of flunixin meglumine (FM) on tendon healing after experimentally induced acute trauma. Twenty eight adult male New Zealand White rabbits were subjected to complete transection of deep digital flexor tendons followed by suture placement. Treatment group received intramuscular injection of FM for three days, and controls received placebo. Subsequently, cast immobilization was continued for two weeks. Animals were sacrificed four weeks after surgery and tissue samples were taken. The histological evaluations revealed improved structural characteristics of neotendon formation including fibrillar linearity, fibrillar continuity and neovascularization in treatment group compared to those of controls (p < 0.05). However, no significant differences were found between two groups in terms of epitenon thickness (p > 0.05). Mechanical evaluation revealed significant increase in load-related material properties including ultimate load, yield load, energy absorption and ultimate stress in treatment group compared to those of control group (p < 0.05). However, no statistically significant differences in terms of stiffness and ultimate strain were found (p > 0.05). The present study showed that intramuscular injection of FM resulted in improved structural and mechanical properties of tendon repairs and it could be an effective treatment for acute tendon injuries like severance and laceration.

Abstract Tendon never restores the complete biological and mechanical properties after healing. Bone marrow and recently adipose tissue have been used as the sources of mesenchymal stem cells, which have been proven to enhance tendon healing. Stromal vascular fraction (SVF), derived from adipose tissue by an enzymatic digestion, represents an alternative source of multipotent cells, which undergo differentiation into multiple lineages to be used in regenerative medicine. In the present study, we investigated potentials of this source on tendon healing. Twenty rabbits were divided into control and treatment groups. Five rabbits were used as donors of adipose tissue. The injury model was unilateral complete transection through the middle one third of deep digital flexor tendon. Immediately after suture repair, either fresh stromal vascular fraction from enzymatic digestion of adipose tissue or placebo was intratendinously injected into the suture site in treatments and controls, respectively. Cast immobilization was continued for two weeks after surgery. Animals were sacrificed at the third week and tendons underwent histological, immunohistochemical, and mechanical evaluations. By histology, improved fibrillar organization and remodeling of neotendon were observed in treatment group. Immunohistochemistry revealed an insignificant increase in collagen type III and I expression in treatments over controls. Mechanical testing showed significant increase in maximum load and energy absorption in SVF treated tendons. The present study showed that intratendinous injection of uncultured adipose derived stromal vascular fraction improved structural and mechanical properties of repaired tendon and it could be an effective modality for treating tendon laceration.