Double-wire woven nitinol stent for treating dogs with refractory tracheal collapse: A case series.

This retrospective case series describes the signalments, clinical signs, diagnostic test results, and postoperative complications obtained from the medical records of 10 client-owned dogs that underwent treatment for grade IV tracheal collapse using double-wire woven nitinol stents between October 2017 and September 2021. Respiratory signs resolved in all dogs immediately after tracheal stent placement. Mild to moderate stent fractures were identified in five dogs, of which two showed concurrent respiratory distress necessitating re-stenting after several months. Minor complications, such as stent migration, were absent. The double-wire woven nitinol stent optimised for the canine trachea showed favourable outcomes and minimal complications.

Dose-dependent effect of canine lyophilized platelet on an in vitro hemodilution model.

The transfusion of stored platelets has emerged as an efficient method for treating dogs with thrombocytopenia. However, the availability of fresh platelets is limited in veterinary medicine due to demanding storage conditions. Lyophilized platelets have long shelf lives and can be easily stored, increasing their accessibility for thrombocytopenic dogs. Due to the lack of research and information on the dose effect, canine lyophilized platelets are used at a clinical dosage without research-based evidence. This study was to evaluate the dose effect of lyophilized canine platelets on blood coagulability. Three different concentrations of lyophilized canine platelets were added to in vitro hemodilution blood model, increasing the platelet count by 25, 50, and 100 × 106/ml and coagulation profiles were analyzed. The coagulability was evaluated via the plasma fibrinogen concentration, coagulation time, thromboelastography (TEG), and platelet function analyzer (PFA). Higher concentrations of lyophilized platelets showed dose-dependent association with decreased aPTT and R-time of TEG and increased alpha angle and MA of TEG. These results showed the potential that the higher dose of canine lyophilized platelets better improve blood coagulability than the standard dose and provided the basis for further safety and clinical studies.

Mitigation of gap formation resulting from saw blade in single-cut osteotomy.

Bone loss from the kerf of the sawblade may influence the final outcomes when employing three-dimensional-printed surgical guides. However, no studies have systematically addressed saw blade-induced bone loss. This study aims to quantify bone loss and propose a reduction guide to minimize the fracture gap. The postoperative gap tended to decrease as the amount of gap compensation increased. Osteotomy gaps can be attributed to the thickness of the saw blade, and the proposed methodology addresses this surgical error. Surgeons can proactively plan and design reduction guides with applied compensation using the method described in this study.

Safety evaluation of a buffer used in the lyophilization of canine platelets: type I hypersensitivity reaction in dogs caused by bovine serum albumin.

Introduction: The present study was designed to evaluate the safety of substances generally used in the preparation of lyophilized platelet products (LPPs) because the possibility of an immune response to bovine serum albumin (BSA) was considered high when using previously described technology. Methods: An intradermal skin test, followed by a drug provocation test, was conducted to observe adverse events and identify the substances responsible for an immune response. Five male beagles (2 years old) weighing 12-14 kg were used. The dogs were clinically healthy and had no history of medication use. An intradermal skin test was conducted with each substance [i.e., 4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid, sodium chloride, potassium chloride, sodium bicarbonate, theophylline, trehalose, and BSA] used in the conventional freeze-dry method. Results: In the intradermal skin test, three dogs tested positive at the BSA injection site and showed clinical signs after the intradermal injection, including nausea and vomiting. For the drug provocation test, all dogs received two intravenous injections of an LPP buffer solution. The initial injection was devoid of BSA, whereas the subsequent injection contained BSA. The three dogs that had reacted to BSA in the intradermal skin test exhibited adverse events such as lethargy, vomiting, and nausea immediately after intravenous injection of the LPP buffer containing BSA. All dogs recovered uneventfully after symptomatic treatment in both tests. Discussion: The high incidence and severity of type I hypersensitivity reactions observed in this study suggested that BSA is unsuitable as a component of canine LPP.

Pulmonary passage of canine adipose tissue-derived mesenchymal stem cells through intravenous transplantation in mouse model.

IMPORTANCE: The intravenous administration of adipose tissue-derived mesenchymal stem cells (AdMSCs) in veterinary medicine is an attractive treatment option. On the other hand, it can result in severe complications, including pulmonary thromboembolism (PTE). OBJECTIVE: The present study assessed the occurrence of PTE after the intravenous infusion of canine AdMSCs (cAdMSCs) into experimental animals. METHODS: Five-week-old male BALB/c hairless mice were categorized into groups labeled A to G. In the control group (A), fluorescently stained 2 × 106 cAdMSCs were diluted in 200 µL of suspension and injected into the tail vein as a single bolus. The remaining groups included the following: group B with 5 × 106 cells, group C with 3 × 106 cells, group D with 1 × 106 cells, group E with 1 × 106 cells injected twice with a one-day interval, group F with 2 × 106 cells in 100 µL of suspension, and group G with 2 × 106 cells in 300 µL of suspension. RESULTS: Group D achieved a 100% survival rate, while none of the subjects in groups B and C survived (p = 0.002). Blood tests revealed a tendency for the D-dimer levels to increase as the cell dose increased (p = 0.006). The platelet count was higher in the low cell concentration groups and lower in the high cell concentration groups (p = 0.028). A histological examination revealed PTE in most deceased subjects (96.30%). CONCLUSIONS AND RELEVANCE: PTE was verified, and various variables were identified as potential contributing factors, including the cell dose, injection frequency, and suspension volume.

Application of Bifurcated Semitendinosus Muscle Transposition for Treatment of Fecal Incontinence in Two Dogs.

A 4-year-old mixed breed dog and a 19-year-old English cocker spaniel dog were evaluated for fecal incontinence. The second dog's fecal incontinence was associated with the anal mass. In both dogs, reconstruction of the external anal sphincter was required to gain fecal continence. Especially in the dog with an anal mass, the whole musculature involved in fecal continence was removed with the affected anorectum. Conventional surgical treatments for fecal incontinence have limitations in terms of muscle flap length and complexity of the surgical procedure. A modified surgical technique using the semitendinosus muscle was devised in the present study to overcome these limitations. The distal part of the semitendinosus muscle was bifurcated to make two muscle bundles, used to completely encircle the anorectum. These muscle bundles were sutured to the surrounding rectal muscle and the pelvic diaphragm to simulate the function of the external anal sphincter. Three months after surgery, both dogs showed significantly improved fecal continence without severe complications, such as infection, dehiscence, or lameness of the limb where the semitendinosus muscle was harvested. The outcomes of the two dogs supported the acceptability of the bifurcated muscle flap for anal sphincter augmentation. In addition, this report showed the possibility of more diverse applications of semitendinosus muscle in dogs.

Orthotopic ureterocele with concurrent ureteral urothelial carcinoma in a dog.

A ureterocele is a rare congenital anomaly with cystic dilation of the terminal segment of the ureter entirely within the bladder (orthotopic) or associated with ectopic ureter (ectopic). Its aetiology has not been fully clarified; however, it may involve genetic or acquired factors. Urothelial carcinoma (UC) is the most common type of canine urinary tract neoplasm, among which over 90% of cases are invasive. The non-papillary (flat) non-infiltrating form accounts for a very small percentage of canine UCs and is considered carcinoma in situ (CIS). The neoplastic cells of CIS remain within the ureteral mucosa and do not breach the basement membrane. UCs originating from the canine ureter are extremely rare, and no report of a ureteral UC concurrently occurring with a ureterocele has been reported. A 7-year-old castrated male Maltese dog weighing 3.5 kg was referred with a 2-week history of lethargy, anorexia, pollakiuria and intermittent panting. The dog underwent open surgery for removal of bladder calculi 2 years prior, and at the time of the surgery, no other urinary system abnormalities were identified. Ultrasonographic and computed tomographic scans revealed a severely enlarged right kidney and ureter with a ureterocele on the ipsilateral side. A diagnosis of an orthotopic ureterocele causing hydronephrosis and hydroureter was established. Complete nephroureterectomy and ureterocelectomy using the marsupialisation technique were performed. The postoperative histological examination of the excised tissues showed a multifocal carcinoma in situ (non-papillary non-infiltrating UC) in the proximal ureter and a fluid-filled kidney with a thin rim of fibrotic renal tissue. No neoplastic changes were observed in the ureterocele tissue. Postoperatively, the dog recovered rapidly without complications except temporary urinary incontinence, and no evidence of tumour recurrence was detected by ultrasonography performed 6 months after surgery. This case report describes the first case of a dog with an orthotopic ureterocele and ureteral UC, which occurred concurrently at the ipsilateral side of the ureter. The condition was successfully managed with a nephroureterectomy and partial ureterocelectomy.

Case Report: Giant Multiloculated Pseudocystic Jejunal Leiomyosarcoma in a Dog: Atypical Morphologic Features of Canine Intestinal Leiomyosarcoma.

A 10-year-old intact female Rottweiler dog weighing 29 kg presented with 2 days history of vomiting, anorexia, and lethargy to KonKuk University Teaching Hospital, Seoul, South Korea. Ultrasonography and computed tomography (CT) scannings revealed a well-demarcated, large mass (29 × 19 × 11 cm) with numerous fluid-filled cavities. Metastases to adjacent lymph nodes were also identified on CT. This large mass and the affected intestinal segments were excised for palliative purposes. Postoperatively, the dog recovered uneventfully without any complications. The cut surface of the mass showed an exophytic growth pattern of multiloculated cystic lesions filled with serosanguineous fluid, large cavities filled with necrotic exudate, and fistulous connections between the intestinal lumen and the necrotic cavity in the mass. On histopathology, the mass was a spindle cell neoplasm expanding from the jejunal muscular layer and with pseudocystic changes. Additional immunohistochemical analysis using antibodies against smooth muscle actin, desmin, and CD-117 demonstrated that the mass was consistent with a leiomyosarcoma. Six months post-operatively, plain radiography revealed an abdominal mass, suspected to be recurrence from jejunal leiomyosarcoma. The owner decided to euthanize the dog due to financial constraints. This case report describes the atypical morphology and clinical progression of a large canine jejunal leiomyosarcoma, which had similar clinical features as those of human leiomyoma and leiomyosarcoma.

The Advantage of the Supercooling Storage Method for Transplantable Sources: Human Umbilical Vessel Endothelial Cells and Mouse Skin Grafts.

BACKGROUND: The safety and efficacy of preserving transplantable tissue depends on multiple factors including temperature, length of preservation, and types of solvent. Supercooling storage, in which the preservation temperature goes below the freezing point without actual freezing of the tissue, has the potential to substantially extend the preservation time of cells, tissues, and organs. Herein we studied the effect of supercooling storage on preserving the viability of transplantable biomaterials. METHODS: Human umbilical vein endothelial cells (HUVECs) and mouse dorsal skin grafts were stored at 2 different temperature (4°C and -4°C). The viability of these tissues was assessed using trypan blue exclusion assay, tetrazolium salt (WST-8) assay, and proliferating cell nuclear antigen immunohistochemistry analysis at various time points. RESULTS: Over time, the viability of HUVECs and mouse skin grafts decreased in each group and at both storage temperatures. The viability of HUVECs, evaluated with trypan blue exclusion assay and WST-8 assay, was better preserved during supercooled storage (-4°C) compared with refrigerated storage (4°C). Mouse skin grafts preserved under supercooled conditions showed less damage and a higher level of proliferating cell nuclear antigen expression. CONCLUSION: Among various preservation techniques, supercooling storage is 1 option to maintain optimal conditions for an increased organ transplantation success rate. To maximize preservation effectiveness, further investigations into the optimal supercooling temperatures, storage solvents, and cell protectants for various cells, tissues, and organs are needed.

Study on the Viability of Canine Nose Pattern as a Unique Biometric Marker.

The uniqueness of the canine nose pattern was studied. A total of 180 nose images of 60 dogs of diverse age, gender, and breed were collected. The canine nose patterns in these images were examined visually and by a biometric algorithm. It was found that the canine nose pattern remains invariant regardless of when the image is taken; and that the canine nose pattern is indeed unique to each dog. The same study was also performed on an enlarged dataset of 278 nose images of 70 dogs of 19 breeds. The study of the enlarged dataset also leads to the same conclusion. The result of this paper confirms and enhances the claims of earlier works by others that the canine nose pattern is indeed unique to each animal and serves as a unique biometric marker.