Clinical evaluation and surgical intervention for diaphragmatic eventration mimicking peritoneopericardial hernia in a cat.

A 2-year-old spayed female British Shorthair cat presented with an increased frequency and duration of cough since infant period. Based on radiographic, ultrasonographic, and computed tomography findings, peritoneopericardial diaphragmatic hernia was considered so that repair surgery was planned. During celiotomy, lax diaphragm was identified instead of defect. Transabdominal diaphragmatic plication was performed to resolve lax diaphragm and to prevent recurrence by overlapping relatively normal part of diaphragm. Diagnosed with diaphragmatic eventration postoperatively, the cat showed improvement in clinical signs and imaging results. Transabdominal diaphragmatic plication is a suitable treatment; the patient maintained normally during a 14-month follow-up period.

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.

Fatigue analysis of canine tracheal stents using the finite element method.

This study aimed to evaluate fatigue of three stent designs when various forces are applied and perform a comparative analyses. A computer simulation using the finite element method was performed. In particular, we constructed a three-dimensional finite element model of nitinol stents with three designs (S6: single-woven wire, wire diameter: 0.006 inch; D6: double-woven wire, wire diameter: 0.006 inch, and D7: double-woven wire, wire diameter: 0.007 inch) that are used to treat canine tracheal collapse (TC). The stents were subjected to a 200 mmHg compression force, a pure torsion force in a perpendicular direction, and a bending-torsion force combining perpendicular and axial forces. The von Mises stress was calculated to evaluate the extent of stent displacement, and Goodman diagrams were plotted to compare fatigue life cycles. D7 exhibited a longer fatigue life compared to S6 and D6. Under compression, pure torsion, and bending-torsion forces, displacement was the smallest for D7, followed by D6 and S6. Similarly, the fatigue life was the longest for D7, followed by D6 and S6. S6 showed the greatest displacement when subjected to external forces; among stents designed using the same wire, D6 displayed less displacement than S6, and D7 exhibited superior fatigue life when subjected to varying degrees of force. This study showed that the structural stability and fatigue life of stents could be effectively compared using finite element method D7 has the greatest stability and structural rigidity under cyclic load.

Reconstructive surgery with an autologous bone graft in a dog with presumptive chronic non-bacterial osteomyelitis.

A 15-year-old Cocker Spaniel was referred to for the evaluation of left forelimb lameness. Radiographic and computed tomography examinations revealed osteolysis of the proximal left third, fourth and fifth metacarpal bones and pathological fractures of the proximal left fourth metacarpal bone. Histopathological examination via bone biopsy did not provide a definitive diagnosis, and the owner elected limb-sparing surgery. The fourth metacarpal bone and digits were amputated. Subsequently, autologous bone grafts were performed on the lytic area of the third and fifth metacarpal bones. The dog showed improvement in gait 7 weeks after reconstructive surgery. Chronic non-bacterial osteomyelitis (CNO) was diagnosed by exclusion. To the best of our knowledge, CNO has not been previously reported in dogs.

Case report: Adjuvant therapy with toceranib for an incompletely resected renal cell carcinoma with suspected pulmonary metastasis in a dog.

Primary renal neoplasia is rare in humans and dogs, with renal cell carcinoma (RCC) being the most common form of this cancer. As RCC is often diagnosed at an advanced stage, pulmonary metastasis is frequently observed. Tyrosine kinase inhibitors (TKIs) are the standard adjuvant treatments for metastatic RCC in humans. Similarly, in veterinary medicine, recent trials have employed TKIs for early-stage RCC patients who underwent complete surgical resection and showed no distant metastasis. However, the use of TKIs has not yet been reported commonly in cases of advanced RCC with metastasis. This case study presents the first clinical outcomes of TKI therapy in a dog with incompletely resected RCC and metastasis. A 5-year-old spayed female Chihuahua was referred to our hospital with a right renal mass and multiple pulmonary nodules suspected to be metastases. A portion of the renal mass was surgically removed, and histopathological examination revealed RCC with a high mitotic index. Adjuvant chemotherapy was administered, owing to incomplete resection with suspected pulmonary metastasis. An anticancer drug response prediction test was conducted using patient tissues. Since toceranib showed the most favorable responsiveness, it was selected as a therapeutic agent. Toceranib was orally administered at a dosage of 2.27 mg/kg every 48 h. Regular medical records for potential adverse effects were obtained, including systemic blood pressure, complete blood count, serum biochemical examination, and urinalysis. After 2 weeks of toceranib therapy, partial remission of pulmonary nodules continued for 2 months. The patient did not experience any adverse effects of the anticancer drug during the 4-month follow-up period. However, the patient died from an unidentified cause 6 months after the initial detection of the renal mass. This report describes the use of toceranib in dogs with RCC. In the present case, the patient showed an initial response to chemotherapy, and despite the presence of several poor prognostic factors, the dog survived beyond the expected 3-month lifespan to 6 months. Notably, no adverse events were observed during treatment.

Long-term adjuvant metronomic chemotherapy in a dog with recurrent maxillofacial osteosarcoma.

Osteosarcoma (OSA) is the most common malignant bone tumour in dogs; however, OSA of the maxilla is uncommon compared to appendicular OSA. Oral melanoma also commonly occurs in dogs with frequent distant metastasis. The role of adjuvant chemotherapy has been questioned in maxillary OSA and melanoma. A 17-year-old English Cocker Spaniel was referred with a growing mass on the right maxilla and a right lower lip mass. Osteosarcoma was diagnosed after partial maxillectomy, and the right lower lip mass was diagnosed as oral melanoma. Metronomic chemotherapy (MC) was performed, and the number of doses was tapered due to side effects at 5 weeks after initiation of MC. After 130 weeks of MC, chemotherapy was suspended due to kidney disease. After the suspension of chemotherapy, findings suggesting recurrence and metastasis were detected. The dog suddenly died 193 weeks after surgery, which was 8-14 times longer than the expected survival time. To the best of our knowledge, this is the first case report of successful long-term combination therapy, including surgery and MC, in a dog with maxillary OSA and lip melanoma. Our results show that the survival time can be greatly extended if MC is performed with proper management.

The biomechanical and biological effect of supercooling on cortical bone allograft.

BACKGROUND: The need for a storage method capable of preserving the intrinsic properties of bones without using toxic substances has always been raised. Supercooling is a relatively recently introduced preservation method that meets this need. Supercooling refers to the phenomenon of liquid in which the temperature drops below its freezing point without solidifying or crystallizing. OBJECTIVES: The purpose of this study was to identify the preservation efficiency and applicability of the supercooling technique as a cortical bone allograft storage modality. METHODS: The biomechanical effects of various storage methods, including deep freezing, cryopreservation, lyophilization, glycerol preservation, and supercooling, were evaluated with the three-point banding test, axial compression test, and electron microscopy. Additionally, cortical bone allografts were applied to the radial bone defect in New Zealand White rabbits to determine the biological effects. The degree of bone union was assessed with postoperative clinical signs, radiography, micro-computed tomography, and biomechanical analysis. RESULTS: The biomechanical properties of cortical bone grafts preserved using glycerol and supercooling method were found to be comparable to those of normal bone while also significantly stronger than deep-frozen, cryopreserved, and lyophilized bone grafts. Preclinical research performed in rabbit radial defect models revealed that supercooled and glycerol-preserved bone allografts exhibited significantly better bone union than other groups. CONCLUSIONS: Considering the biomechanical and biological superiority, the supercooling technique could be one of the optimal preservation methods for cortical bone allografts. This study will form the basis for a novel application of supercooling as a bone material preservation technique.

Anti-Staphylococcal Activity of Ligilactobacillus animalis SWLA-1 and Its Supernatant against Multidrug-Resistant Staphylococcus pseudintermedius in Novel Rat Model of Acute Osteomyelitis.

Osteomyelitis caused by staphylococcal infection is a serious complication of orthopedic surgery. Staphylococcus pseudintermedius is the main causative agent of osteomyelitis in veterinary medicine. Methicillin-resistant S. pseudintermedius (MRSP) has been reported in companion animals, especially dogs. Multidrug-resistant S. pseudintermedius is an emerging pathogen and has acquired antibiotic resistance against various commercial antimicrobial agents. New antimicrobial compounds are urgently needed to address antibiotic resistance, and the development of novel agents has become an international research hotspot in recent decades. Antimicrobial compounds derived from probiotics, such as bacteriocins, are promising alternatives to classical antibiotics. In this study, the antibacterial activities of Ligilactobacillus animalis SWLA-1 and its concentrated cell-free supernatant (CCFS) were evaluated in vitro and in vivo. The CCFS of this bacterium showed no toxicity against osteoblast and myoblast cells in vitro, while significantly inhibiting the multidrug-resistant S. pseudintermedius KUVM1701GC strain in a newly established rat model. The CCFS significantly inhibited multidrug-resistant staphylococci both in vitro and in vivo. This suggests that CCFS derived from L. animalis SWLA-1 has potential as an alternative to classic antibiotics for staphylococcal infections in dogs.

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.

A rabbit model of tracheal collapse for optimal self-expanding metal stents.

Investigating the characteristics of tracheas can help the understanding of diseases related to the trachea, particularly tracheal collapse (TC) in dogs. This study aimed to compare the mechanical properties of tracheas from New Zealand White (NZW) rabbits and dogs and to introduce a method for inducing a model of TC in the normal trachea. Tracheal samples were obtained from NZW rabbit cadavers (n=5) weighing 3.62-3.92 kg and from dog cadavers (n=5) weighing 2.97-3.28 kg. Three live NZW rabbits weighing 3.5-4.0 kg were used to establish the model. The radial forces of both sample sets were measured using a digital force gauge and statistically compared. Subsequently, TC was surgically induced in three female NZW rabbits by physically weakening their tracheal cartilage under general anesthesia. Their clinical signs were monitored for 3 months, and radiographic examinations were performed monthly for 3 months. The mean radial forces of the two sample sets were comparable (P>0.05). The clinical signs, radiographic examinations, and macroscopic examinations were all comparable to those of dogs with TC. The cadaveric study between the rabbits and dogs demonstrated that the surgically induced rabbit model of TC is an excellent candidate for the experimental study of dogs with TC. This study also provides a reference of tracheal radial force values to enable selection of appropriate mesh types and wire diameters of self-expanding metal stents.

Adjuvant therapy with toceranib for hepatocellular carcinoma and cholangiocarcinoma in a Pomeranian.

A 10-year-old spayed female Pomeranian dog was referred for hepatic mass evaluation. Blood tests revealed mildly elevated alkaline phosphatase activities. Computed tomography revealed a mass with multiple nodules on the right hepatic medial lobe adjacent to the caudal vena cava; histopathology confirmed mixed hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). Because of incomplete resection, adjuvant therapy was recommended. As tumour cells showed PDGFR-α, c-Kit, and FGFR1 overexpression, the anticancer effect of tyrosine kinase inhibitors was evaluated on the cells; toceranib was the most effective and was administered starting with an extra-labelled dose. The dog remained stable for 2.3 years with mild adverse effects. To our knowledge, this is the first successful clinical application of toceranib in a dog with mixed HCC-CC.

Cystadenocarcinoma of the intrahepatic bile duct in a dog.

A 14-year-old spayed female Shih-Tzu was referred to the Veterinary Medical Teaching Hospital of Konkuk University for evaluation of an abdominal mass. In diagnostic imaging, two large cystic masses were identified. The affected liver lobes were surgically resected, and the specimens were submitted for histopathological evaluation and immunohistochemical staining. The two cystic lesions were diagnosed as biliary cystadenocarcinoma (BCAC). Recurrence and regional invasion were identified on ultrasonography 36 days postoperatively. The patient died on postoperative day 271. To the best of our knowledge, previously reported case studies of BCAC in dogs presented limited clinical information. In this report, we present a detailed picture comprising a range of clinical information and histopathological examination of BCAC in a dog.

Comparison of three different self-expanding metal stents using rabbit models for the treatment of tracheal collapse.

PURPOSE: To identify an optimal self-expandable metallic stent (SEMS) and verify whether a mechanically superior SEMS would result in better clinical outcomes in the treatment of tracheal collapse. METHODS: We selected three SEMS (n = 8 each), including an S-type stent with a wire diameter of 0.006 inches (S6) and two D-type stents with wire diameters of 0.006 (D6) and 0.007 inches (D7). Twenty-four New Zealand White rabbits were divided into three equal groups. After the stents were deployed, the clinical signs were recorded daily, and radiographic examinations were performed monthly. All rabbits were euthanized after three months. RESULTS: Two rabbits with S6 stents and one rabbit with a D7 stent died within three months because of stent migration or pneumonia. All rabbits with D6 stents survived for three months. On histological examination, the D6 group had the lowest inflammation score. CONCLUSIONS: Both clinically and histopathologically, the results with D-type stents with a wire diameter of 0.006 inches were superior to those of the other groups (p = 0.001). The use of an optimal intraluminal stent may improve the long-term clinical outcomes in the treatment of tracheal collapse in dogs.

Use of coccygeal vertebra autograft and platelet-rich plasma for treating a distal radial nonunion fracture in a small-breed dog.

A 4.3-kg, 11-month-old, spayed female poodle was presented for treatment of a right radio-ulnar nonunion fracture. Clinical history included failed surgical correction of a radius fracture with internal fixation 1 mo before presentation. Radiographic examination revealed a 1.5-cm lytic lesion on the right distal radius. Surgery was planned with a coccyx autograft and platelet-rich plasma. A 2.8-cm-long bone defect was created, and the lytic lesion was removed. Caudectomy was performed; the 6th and 7th coccygeal bones were harvested, placed into the defect, and fixed to the radius with a locking plate. Remnants of coccygeal bone were ground, mixed with platelet-rich plasma, and used to fill the bone defects. There was no evidence of nonunion or delayed union at the 18-month follow-up examination. Key clinical message: Based on the study findings, we inferred that a coccyx autograft and platelet-rich plasma can be used for successful reconstruction of a distal radial defect.

Utilisation d'une autogreffe de vertèbre coccygienne et de plasma riche en plaquettes pour le traitement d'une fracture radiale distale avec non-union chez un chien de petite race. Une femelle caniche stérilisée de 4,3 kg, âgée de 11 mois, a été présentée pour le traitement d'une fracture radio-ulnaire droite avec non-union. Les antécédents cliniques comprenaient l'échec de la correction chirurgicale d'une fracture du radius avec fixation interne 1 mois avant la présentation. L'examen radiographique a révélé une lésion lytique de 1,5 cm sur le radius distal droit. La chirurgie était prévue avec une autogreffe de coccyx et du plasma riche en plaquettes. Un défaut osseux de 2,8 cm de long a été créé et la lésion lytique a été retirée. Une caudectomie a été réalisée; les 6e et 7e os coccygiens ont été prélevés, placés dans le défaut et fixés au radius avec une plaque de verrouillage. Les restes d'os coccygien ont été broyés, mélangés avec du plasma riche en plaquettes et utilisés pour combler les défauts osseux. Il n'y avait aucune évidence de non-union ou de retard de consolidation lors de l'examen de suivi à 18 mois.Message clinique clé :Sur la base des résultats de l'étude, nous avons déduit qu'une autogreffe de coccyx et du plasma riche en plaquettes peuvent être utilisés pour une reconstruction réussie d'un défaut radial distal.(Traduit par Dr Serge Messier).

Evaluation of mechanical properties of self-expanding metal stents for optimization of tracheal collapse in dogs.

The objective of this study was to compare the mechanical properties, including radial, axial, and bending forces, of various self-expanding metal stents with different wire diameters. The radial forces generated through longitudinal and cylindrical compression, along with axial and bending forces, were measured and used to evaluate the mechanical properties of 3 types of self-expanding metal stents (n = 3); the most suitable type was further assessed with 4 different wire diameters (n = 3). The D-type stent (double-wire woven uncovered nitinol stent) had the highest radial force and the lowest axial force and hence, was the most suitable for clinical use; however, its bending force was the lowest, corroborating the results of the axial force measurements. Therefore, the D-type stent was further evaluated using the following wire diameters: i) 0.127, ii) 0.152, iii) 0.178, and iv) 0.203 mm. When the wire diameter was increased by 0.025 mm, the measured radial, axial, and bending forces increased significantly. Thus, the adequate wire diameter should be determined based on the anatomical structure of stents. The mechanical properties of self-expanding stents should be considered in selecting the optimal design for tracheal collapse in dogs.

L'objectif de cette étude était de comparer les propriétés mécaniques, incluant les forces radiale, axiale et de flexion, de différentes endoprothèses métalliques auto-expansibles ayant des fils de diamètres différents. Les forces radiales générées par la compression longitudinale et cylindrique, avec les forces radiale et de flexion, ont été mesurées et utilisées pour évaluer les propriétés mécaniques de trois types d'endoprothèses métalliques auto-expansible (n = 3); le type le plus approprié étant ensuite évalué avec quatre diamètres différents de fil (n = 3). L'endoprothèse de type D (endoprothèse en nitinol non recouverte tissée à double fil) avait la force radiale la plus élevée et la force axiale la plus faible et ainsi, était la plus appropriée pour utilisation clinique; toutefois, sa force de flexion était la plus faible, corroborant les résultats les mesures de la force axiale. Donc, l'endoprothèse de type D a été évaluée davantage en utilisant les diamètres de fil suivants: i) 0,127, ii) 0,152, iii) 0,178, et iv) 0,203 mm. Lorsque le diamètre du fil était augmenté de 0,025 mm, les forces radiale, axiale, et de flexion mesurées augmentèrent de manière significative. Ainsi, le diamètre de fil adéquat devrait être déterminé basé sur la structure anatomique de l'endoprothèse. Les propriétés mécaniques des endoprothèses auto-expansibles devraient être prises en considération lors de la sélection du design optimal pour un collapse de la trachée chez le chien.(Traduit par Docteur Serge Messier).

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: Toceranib as adjuvant chemotherapy in a dog with incompletely resected combined hepatocellular-cholangiocarcinoma.

An 11-year-old intact female mixed breed dog was presented with abdominal distention and elevated hepatic enzyme levels. Computed tomography revealed a multicystic hepatic mass at the left medial lobe adjacent to the diaphragm and caudal vena cava. The mass was surgically removed with partial hepatectomy, but it could not be removed completely because of adhesion to the diaphragm. The tissue was submitted for histopathologic evaluation, and the patient was diagnosed with stage IIIA combined hepatocellular-cholangiocarcinoma (cHCC-CC). Considering the residual tumor tissue from incomplete surgical excision, adjuvant chemotherapy was recommended. Tumor tissue obtained from the patient was assessed using an anticancer drug response prediction test, and the results showed that toceranib phosphate was the most effective chemotherapeutic agent for this patient. Toceranib was initiated (3.1 mg/kg, PO, q48 h), and routine adverse effect assessment, including systemic blood pressure measurement, complete blood count, serum biochemical evaluations, and urinalysis were performed at two-week intervals for the first 2 months and every 2 months thereafter. Radiography and ultrasonography were conducted at one-month intervals for the first two months and then every 2 months subsequently. Concurrent hyperadrenocorticism was managed with trilostane (1 to 5 mg/kg, PO, q12h). The patient showed no critical adverse effects of chemotherapy, obvious recurrence, or metastasis. The response to toceranib was assessed as a partial response, and the patient is still alive over 23 months after tumor excision. This is the first case report describing chemotherapy for a dog with cHCC-CC.

Different outcomes of multiple sialadenitis involving the submandibular and zygomatic salivary glands in a Welsh Corgi dog.

A ten-year-old indoor, castrated male Cardigan Welsh Corgi (Canis familiaris) presented with the chief complaints of chronic vomiting, retching, hypersalivation, and bilateral submandibular masses for two months. The systemic examinations, including serum chemistry, radiography, ultrasonography, and fluoroscopy, were unremarkable. A fine-needle aspiration revealed bilateral submandibular sialadenitis. Broad-spectrum antibiotics with phenobarbital were prescribed to alleviate the ptyalism. Thereafter, the left submandibular glands were normalised, and the right submandibular glands decreased to half their size. Three weeks later, the animal had an emergency visit because of a sudden left exophthalmos. Computed tomography and magnetic resonance imaging revealed enlarged left zygomatic and right mandibular salivary glands. The affected glands were surgically removed; the histopathologic examination confirmed non-septic sialadenitis, and the patient was finally diagnosed with idiopathic sialadenitis. Vomiting continued after the gland removal and the dog required a gradual increase in the phenobarbital dosage and an additional antiepileptic drug (potassium bromide) to manage the symptoms. The patient died eight months later from an unknown cause. This case report of bilateral submandibular sialadenitis concurrent with unilateral zygomatic sialadenitis in a Welsh Corgi dog suggests that when multiple salivary glands are involved, the response to anti-epileptic drugs and the prognosis is poor compared to that involving a single salivary gland.

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.

Establishment of Canine Transitional Cell Carcinoma Cell Lines Harboring BRAF V595E Mutation as a Therapeutic Target.

Transitional cell carcinoma (TCC) is the most common malignant tumor of the canine urinary tract and tends to have a poor prognosis due to its invasive potential. Recent studies have reported that up to 80% of canine urothelial carcinoma has the BRAF V595E mutation, which is homologous to the human V600E mutation. Activating the BRAF mutation is an actionable target for developing effective therapeutic agents inhibiting the BRAF/mitogen-activated protein kinase (MAPK) pathway in canine cancer as well as human cancer. We established novel canine TCC cell lines from two tumor tissues and one metastatic lymph node of canine TCC patients harboring the BRAF V595E mutation. Tumor tissues highly expressed the BRAF mutant and phosphorylated extracellular signal-related kinases (ERK)1/2 proteins. The derived cell lines demonstrated activated MAPK pathways. We also evaluated the cell lines for sensitivity to BRAF inhibitors. Sorafenib, a multiple kinase inhibitor targeting RAF/vascular endothelial growth factor receptor (VEGFR), successfully inhibited the BRAF/MAPK pathway and induced apoptosis. The established canine TCC cell lines responded with greater sensitivity to sorafenib than to vemurafenib, which is known as a specific BRAF inhibitor in human cancer. Our results demonstrated that canine TCC cells showed different responses compared to human cancer with the BRAF V600E mutation. These cell lines would be valuable research materials to develop therapeutic strategies for canine TCC patients.