Suspected malnutrition-induced reversible feline skin fragility syndrome in a cat with congenital axial deformities.

A stray cat, an intact female Japanese domestic shorthair cat of unknown age (suspected to be a young adult), was rescued. The cat was lethargic and thin and had marked skin fragility, delayed wound healing without skin hyperextensibility, and hind limb proprioceptive ataxia and paresis. Survey radiography, computed tomography, and magnetic resonance imaging revealed congenital vertebral anomalies, including thoracolumbar transitional vertebrae, scoliosis resulting from a thoracic lateral wedge-shaped vertebra, and a kinked tail, and a dilated spinal cord central canal. Through nutritional support, the cat's general condition normalized, followed by a gradual and complete improvement of skin features. Whole-genome sequencing was completed; however, no pathogenic genetic variant was identified that could have caused this phenotype, including congenital scoliosis. A skin biopsy obtained 7 y after the rescue revealed no remarkable findings on histopathology or transmission electron microscopy. Based on clinical course and microscopic findings, malnutrition-induced reversible feline skin fragility syndrome (FSFS) was suspected, and nutritional support was considered to have improved the skin condition. Key clinical message: This is the second reported case of presumed malnutrition-induced reversible FSFS and was accompanied by long-term follow-up.

Syndrome de fragilité cutanée réversible induit par la malnutrition soupçonné chez un chat avec des difformités axiales congénitales. Un chat errant, une femelle intacte de race japonaise à poil court et d'âge inconnu (suspecté être une jeune adulte), a été secourue. La chatte était léthargique et maigre, et avait une fragilité marquée de la peau, un retard dans la guérison de plaies sans hyperextensibilité de la peau, et une ataxie proprioceptive et parésie des membres postérieurs. Des radiographies, un examen par tomodensitométrie, et de l'imagerie par résonnance magnétique ont révélé des anomalies congénitales des vertèbres, incluant des vertèbres transitionnelles thoraco-lombaires, une scoliose résultant d'une vertèbre thoracique en forme de coin, une queue pliée, et un canal central de la moelle épinière dilaté. Grâce à un soutien nutritionnel, la condition générale du chat s'est stabilisée, suivi d'une amélioration graduelle et complète des caractéristiques de la peau. Le séquençage du génome complet a été effectué; toutefois, aucune variation génétique pathogénique n'a été identifiée qui aurait pu causer ce phénotype, incluant la scoliose congénitale. Une biopsie cutanée obtenue 7 j après le sauvetage n'a révélé aucune trouvaille spéciale à l'histopathologie ou par microscopie électronique à transmission. Basé sur le déroulement clinique et l'examen microscopique, le syndrome de fragilité cutanée réversible félin induit par la malnutrition (FSFS) était suspecté, et le soutien nutritionnel a été considéré comme ayant amélioré la condition cutanée.Message clinique clé :Ce cas est le deuxième cas rapporté de FSFS induit par la malnutrition soupçonné et a fait l'objet d'un suivi à long terme.(Traduit par Dr Serge Messier).

Pedigree study of the heredity of copper-associated hepatitis in Dalmatians in Japan.

The pedigrees of 3 Dalmatian dogs afflicted with copper-associated hepatitis were investigated to discover the mode of inheritance. A composite family pedigree showed that the 3 affected Dalmatians were related. None of the parents of the affected dogs showed clinical symptoms of liver disease, and the disease had no sex predisposition. The estimated segregation ratio was approximately 3:1 based on surviving littermates. These findings suggested that the copper-associated hepatitis in these Dalmatians was an autosomal recessive mode of inheritance. In addition, some male Dalmatians imported from abroad might have been involved in the occurrence of this disease in Japan.

Étude généalogique de l'hérédité de l'hépatite associée au cuivre chez des Dalmatiens au Japon. Les pedigrees de trois chiens dalmatiens atteints d'hépatite associée au cuivre ont été étudiés pour découvrir le mode de transmission. Un pedigree familial composite a montré que les trois Dalmatiens affectés étaient apparentés. Aucun des parents des chiens affectés n'a présenté de symptômes cliniques de maladie du foie et la maladie n'avait aucune prédisposition associée au genre. Le ratio de ségrégation estimé était d'environ 3:1 sur la base des compagnons de portée survivants. Ces résultats suggèrent que l'hépatite associée au cuivre chez ces Dalmatiens était un mode de transmission autosomique récessif. De plus, certains dalmatiens mâles importés de l'étranger pourraient avoir été impliqués dans l'apparition de cette maladie au Japon.(Traduit par Dr Serge Messier).

Mismatch repair deficiency in canine neoplasms.

The DNA mismatch repair (MMR) system preserves genomic stability by identifying and repairing mismatched nucleotides in the DNA replication process. The dysfunction of the MMR system, also known as mismatch repair deficiency (dMMR), is implicated as a predictive biomarker for the efficacy of immune checkpoint blockade therapy regardless of the tumor type in humans. This study aimed to evaluate the immunolabeling of MMR proteins in canine tumors and to identify the types of tumors having dMMR. First, we performed immunohistochemistry in 8 different canine tumors (oral malignant melanoma, high-to-intermediate grade lymphoma, mast cell tumor, malignant mammary gland tumor, urothelial carcinoma, hepatocellular carcinoma, osteosarcoma, and hemangiosarcoma) with 15 samples each to analyze the immunolabeling of canine mismatch repair proteins (MSH2, MSH6, and MLH1) using anti-human monoclonal antibodies. We found that more than half of canine oral malignant melanoma (60%) and hepatocellular carcinoma (53%) samples and fewer of the other canine tumors had loss of immunolabeling in ≥1 MMR protein (ie, evidence of defective MMR proteins, based on the definition of dMMR in the humans). Antibodies against human MSH2, MSH6, and MLH1 were cross-reactive with the corresponding canine protein as confirmed using MMR gene knockout canine cell lines. Further studies are required to investigate the clinical outcomes in canine spontaneous tumors with dMMR to determine the potential for immune checkpoint blockade therapy for these tumor types.

Establishment of a dog primary prostate cancer organoid using the urine cancer stem cells.

Dog spontaneously develop prostate cancer (PC) like humans. Because most dogs with PC have a poor prognosis, they could be used as a translational model for advanced PC in humans. Stem cell-derived 3-D organoid culture could recapitulate organ structures and physiology. Using patient tissues, a human PC organoid culture system was established. Recent study has shown that urine cells also possess the characteristic of stem cells. However, urine cell-derived PC organoids have never been produced. Therefore, we generated PC organoids using the dog urine samples. Urine organoids were successfully generated from each dog with PC. Each organoid showed cystic structures and resembled the epithelial structures of original tissues. Expression of an epithelial cell marker, E-cadherin, and a myofibloblast marker, α-SMA, was observed in the urine organoids. The organoids also expressed a basal cell marker, CK5, and a luminal cell marker, CK8. CD49f-sorted basal cell organoids rapidly grew compared with CD24-sorted luminal cell organoids. The population of CD44-positive cells was the highest in both organoids and the original urine cells. Tumors were successfully formed with the injection of the organoids into immunodeficient mice. Treatment with a microtubule inhibitor, docetaxel, but not a cyclooxygenase inhibitor, piroxicam, and an mTOR inhibitor, rapamycin, decreased the cell viability of organoids. Treatment with a Hedgehog signal inhibitor, GANT61, increased the radiosensitivity in the organoids. These findings revealed that PC organoids using urine might become a useful tool for investigating the mechanisms of the pathogenesis and treatment of PC in dogs.

Transcatheter arterial embolization in normal canine liver.

OBJECTIVE: To determine the effects of selective transcatheter arterial embolization (TAE) in the normal canine liver. STUDY DESIGN: Experimental study. ANIMALS: Adult Beagle dogs (n = 5). METHODS: Gelatin sponge particles (GSPs) were injected through a microcatheter for selective embolization of the left hepatic artery in normal dogs. Computed tomography (CT) and histology were performed during an 8-week observation period; biochemical analysis data were obtained during a 12-week observation period after TAE. RESULTS: Embolization was successful in all dogs and did not induce any change in the clinical appearance of dogs. Postoperative CT was consistent with recanalization of the artery within 2 weeks of embolization in all dogs. Hepatic enzyme levels increased temporarily after embolization but gradually returned to normal ranges. Histological examinations did not differ between treated and untreated liver tissues. CONCLUSION: TAE appears safe in normal dogs observed for 12 weeks. Arterial recanalization seems to occur within 2 weeks after injection of GSPs in the left hepatic artery. IMPACT/CLINICAL RELEVANCE: Selective TAE of the hepatic artery was well tolerated in normal dogs. Selective TAE may be applicable to canine hepatocellular carcinoma.

Finite element study on post-screw removal stress in toy poodle radius with different plate designs and screw arrangements.

Background: The study employs finite element analysis to investigate stress distribution in the radius of toy poodles after screw removal. The examination focuses on the biomechanical implications of varied screw hole configurations using 1.5 and 2.0-mm locking compression plates (LCPs) with notched head T-Plates. Aim: To provide a noninvasive approach to analyzing the immediate consequences of screw removal from the radius bone in toy poodles. Specifically, it explores the impact of varied plate designs and screw arrangements on stress distribution within the forelimb bones. Methods: The study constructs a three-dimensional bone model of the toy poodle's forelimb based on computed tomography (CT) images. Simulations were designed to replicate jumping and landing from a 40 cm height, comparing stress distribution in the radius post-screw removal. Results: The analysis reveals significant variations in stress distribution patterns between the two LCPs. The radius implanted with the 2.0-mm LCP displays a uniform stress distribution, contrasting with the 1.5-mm plates. Localized stress concentration is observed around the screw holes, while trabecular bone regions near the screw holes exhibit lower stress levels. Conclusion: The study highlights the plate designs and screw configurations that affect bone stress in toy poodle forelimbs post-screw removal. The findings provide valuable insights for veterinarians, aiding informed decisions in veterinary orthopedic practices.

Relationship between clinical parameters and malformations in dogs diagnosed with atlanto-axial instability.

Atlanto-axial instability is a common disease that affects toy-breed dogs. Most cases of atlanto-axial instability are congenital. Furthermore, patients with atlanto-axial instability are predisposed to other concurrent diseases. Therefore, this study aimed to retrospectively determine the presence of concurrent diseases in cases with atlanto-axial instability using imaging data and analyze the relationship between clinical parameters and the incidence of complex malformations. The clinical data and imaging findings of 41 toy-breed dogs diagnosed with atlanto-axial instability were analyzed using their medical records and imaging data. Occipital dysplasia (17/27), atlanto-occipital overlapping (22/34), dens dysplasia (27/41), Chiari-like malformation (8/34), syringomyelia (5/34), lateral ventricular enlargement (20/36), and intracranial arachnoid cyst (5/35) were observed in patients with atlanto-axial instability. The body weight of the patients in the groups with atlanto-occipital overlapping and lateral ventricular enlargement was lower than that of those in the groups without these diseases (1.78 ± 0.71 vs 2.71 ± 1.15 kg, P = 0.0269, 1.60 ± 0.40 vs 2.75 ± 1.08 kg, P = 0.001, respectively). Furthermore, when the correlation between the total number of concurrent diseases and the age at onset and body weight was examined, it became clear that lower body weight was associated with the incidence of a greater number of concurrent diseases. Thus, the findings of this study suggest that toy-breed dogs are more likely to present with complex malformations and should be evaluated carefully with additional examinations and treatment methods.

Elucidation of the radius and ulna fracture mechanisms in toy poodle dogs using finite element analysis.

Fractures occurring in the distal radius and ulna of toy breed dogs pose distinctive challenges for veterinary practitioners, requiring specialized treatment approaches primarily based on anatomical features. Finite Element Analysis (FEA) was applied to conduct numerical experiments to determine stress distribution across the bone. This methodology offers an alternative substitute for directly investigating these phenomena in living dog experiments, which could present ethical obstacles. A three-dimensional bone model of the metacarpal, carpal, radius, ulna, and humerus was reconstructed from Computed Tomography (CT) images of the toy poodle and dachshund forelimb. The model was designed to simulate the jumping and landing conditions from a vertical distance of 40 cm to the ground within a limited timeframe. The investigation revealed considerable variations in stress distribution patterns between the radius and ulna of toy poodles and dachshunds, indicating notably elevated stress levels in toy poodles compared to dachshunds. In static and dynamic stress analysis, toy poodles exhibit peak stress levels at the distal radius and ulna. The Von Mises stresses for toy poodles reach 90.07 MPa (static) and 1,090.75 MPa (dynamic) at the radius and 1,677.97 MPa (static) and 1,047.98 MPa (dynamic) at the ulna. Conversely, dachshunds demonstrate lower stress levels for 5.39 MPa (static) and 231.79 MPa (dynamic) at the radius and 390.56 MPa (static) and 513.28 MPa (dynamic) at the ulna. The findings offer valuable insights for modified treatment approaches in managing fractures in toy breed dogs, optimizing care and outcomes.

Quantitative evaluation of the biomechanical and viscoelastic properties of the dog patellar tendon in response to neuromuscular blockade at different stifle angles.

The patellar tendon (PT) is crucial for maintaining stability and facilitating movement in the stifle joint. Elastography has been recognized as a prominent method for evaluating PT properties in humans and dogs. The utilization of oscillation methods in canine studies remains limited despite their extensive documentation in human studies. Our study represents the first effort to quantitatively assess and compare the effects of muscle relaxant on the biomechanical and viscoelastic characteristics of the PT at varying stifle angles in living dogs. Five healthy female beagles were used in this study. Biomechanical (tone, stiffness, and decrement) and viscoelastic (relaxation time and creep) properties of the PT were measured using MyotonPRO (Myoton Ltd, Estonia) prior to and following administration of rocuronium (0.5 mg/kg/body weight) at normal, extended, and flexed positions. Rocuronium was selected for its safety, controllability, and widespread clinical use in veterinary anesthesia. Two-way analysis of variance showed that tone, stiffness, and decrement were significantly higher (P < 0.001) in the control group than in the muscle relaxation group. At the same time, relaxation time and creep were significantly lower (P < 0.001) in the control group than in the muscle relaxation group. The findings indicate that stifle angle position and muscle rexalant administration fundamentally alter the biomechanical loading conditions of the PT, leading to changes in its viscoelastic properties. Therefore, this novel quantitative data could benefit clinical settings that necessitate accurate and objective methods for risk identification and monitoring PT biomechanics in dogs.

The perfusion index as a method of assessing epidural anaesthesia efficacy in healthy dogs.

Introduction: Perfusion index (PI) is used as assessment of epidural anaesthesia efficacy in human medicine, but its usefulness in dogs is unknown. The aim of this study was to evaluate the usefulness of PI in determining epidural anaesthesia effectiveness. Material and Methods: This is prospective cross-over experimental study. Five healthy adult beagle dogs were anaesthetised and an epidural catheter was inserted in the lumbosacral area and adjusted so that the end of the catheter was placed at the fourth lumbar vertebra. Single-port catheters were used in the control group and multiple-port catheters were used in the treatment group. A PI probe was placed on a hind leg, and the catheter placement was confirmed via computed tomography. The treatment group received a bolus dose of lidocaine, and the control group received saline, via epidural catheter. The PI value was recorded every 5 min until 30 min after lidocaine injection. Results: The PIs of the hind limbs were not significantly different over time, nor were they between the control and lidocaine-injected groups at any point in time. Conclusion: The PI is not useful in determining the efficacy of epidural anaesthesia in dogs under general anaesthesia. In the future, finding a reliable method to evaluate the success of regional anaesthesia, even in patients under general anaesthesia, will be necessary.

Proof-of-concept study of the caninized anti-canine programmed death 1 antibody in dogs with advanced non-oral malignant melanoma solid tumors.

BACKGROUND: The anti-programmed death 1 (PD-1) antibody has led to durable clinical responses in a wide variety of human tumors. We have previously developed the caninized anti-canine PD-1 antibody (ca-4F12-E6) and evaluated its therapeutic properties in dogs with advance-staged oral malignant melanoma (OMM), however, their therapeutic effects on other types of canine tumors remain unclear. OBJECTIVE: The present clinical study was carried out to evaluate the safety profile and clinical efficacy of ca-4F12-E6 in dogs with advanced solid tumors except for OMM. METHODS: Thirty-eight dogs with non-OMM solid tumors were enrolled prospectively and treated with ca-4F12-E6 at 3 mg/kg every 2 weeks of each 10-week treatment cycle. Adverse events (AEs) and treatment efficacy were graded based on the criteria established by the Veterinary Cooperative Oncology Group. RESULTS: One dog was withdrawn, and thirty-seven dogs were evaluated for the safety and efficacy of ca-4F12-E6. Treatment-related AEs of any grade occurred in 13 out of 37 cases (35.1%). Two dogs with sterile nodular panniculitis and one with myasthenia gravis and hypothyroidism were suspected of immune-related AEs. In 30 out of 37 dogs that had target tumor lesions, the overall response and clinical benefit rates were 6.9% and 27.6%, respectively. The median progression-free survival and overall survival time were 70 days and 215 days, respectively. CONCLUSIONS: The present study demonstrated that ca-4F12-E6 was well-tolerated in non-OMM dogs, with a small number of cases showing objective responses. This provides evidence supporting large-scale clinical trials of anti-PD-1 antibody therapy in dogs.

Sulfasalazine, a potent cystine-glutamate transporter inhibitor, enhances osteogenic differentiation of canine adipose-derived stem cells.

Cystine-glutamate transporter (xCT) is a plasma membrane transporter that imports cystine and indirectly contributes to the oxidative stress resistance associated with increased intracellular glutathione levels. Canine adipose-derived stem cells (CADSCs) include an xCT-positive subpopulation and show relatively low expression of osteogenic markers during in vitro osteogenic differentiation. Sulfasalazine (SSZ), a drug used to treat rheumatoid arthritis, suppresses xCT expression in cancer cells. In this study, we found that the SSZ treatment at 100 µM significantly suppressed xCT mRNA expression in CADSCs but did not significantly affect cell proliferation under the same conditions. Additionally, this treatment decreased the intracellular glutathione concentration. During in vitro osteogenic differentiation, the SSZ treatment at 50 µM and 100 µM significantly increased alizarin red staining and its quantification, as well as the concentration-dependent osteogenic differentiation markers (BMP1 and SPP) mRNA expression. Our results suggested that SSZ enhances the osteogenic differentiation potential of CADSCs and can potentially exhibit a superior therapeutic profile in canine bone regenerative medicine.

Comparison of surgical invasiveness between micro-endoscopic discectomy/microscopic discectomy and conventional hemilaminectomy in dogs.

Micro-endoscopic discectomy (MED) or microscopic discectomy (MD) have been performed for disc herniation in humans. The purpose of this study was to compare the invasiveness of the hemilaminectomy in dogs between the approach using a cylindrical retractor for the MED/MD and a conventional open surgical approaches in dogs. First, as preliminary studies, we analyzed the suitability of the cylindrical retractor for the vertebral body of small to medium-sized dogs on the X-ray computed tomographic images using the three-dimensional analysis software, and confirmed that it was possible to open a bone window of an approximate length of 1.72 clto the spinal canal with the cylindrical retractor with a diameter 17 mm using two medium-sized canine cadavers. Next, to determine difference in the invasiveness of hemilaminectomy, the magnitude of tissue damage, surgical stress and postoperative pain were compared between the conventional open approach (hemilaminectomy group: HL group, n=6) and the surgical approach using the cylindrical retractor (MD group, n=6) in 12 beagle dogs. The plasma creatine phosphokinase, C-reactive protein and cortisol concentrations, incision length and University of Melbourne Pain Scale scores after the hemilaminectomy were significantly lower in the MD group than in the HL group. There were no significant differences between the durations of surgery and the other evaluated indices. The approach using the MD can provide a less invasive hemilaminectomy than the conventional approach in dogs.

Osteosarcoma of the hyoid bone in a cat.

Case summary: A 10-year-old male neutered Abyssinian cat was presented with the chief complaint of a right pharyngeal mass. On palpation, the mass was easily palpable; it appeared well demarcated and mobile, and oval in shape. Radiographic examination showed a radiopaque pharyngeal mass, which was revealed to be a well-demarcated mass lesion with a radiopaque marginal area on CT examination. The inside of the mass was uniformly well enhanced on contrast CT examination. A three-dimensional image reconstructed from the CT images strongly suggested that the mass originated from the right stylohyoid bone. No abnormal lesions were observed in the thoracic and abdominal CT examinations. Surgical excision of the mass was scheduled 3 weeks after the first admission. The mass was bluntly separated from the surrounding musculature and resected together with the ipsilateral epihyoid bone adjacent to the mass. Histopathological examination of the resected mass showed neoplastic cells with osteoid formation, and the mass was histopathologically diagnosed as an osteosarcoma. The postoperative recovery from anaesthesia was uneventful, and the cat began feeding on its own from the third postoperative day. The 3-month postoperative CT evaluation revealed no local recurrence or distant metastasis. The cat showed no abnormal findings at the time of writing (6 months postoperatively). Relevance and novel information: Although osteosarcoma derived from the hyoid bone has rarely been reported in the veterinary field, this report suggests that such tumours may occur in cats. In addition, partial excision of the hyoid apparatus seems to be well tolerated in cats.

A Monte Carlo study on dose distribution of an orthovoltage radiation therapy system.

It is important to plan radiotherapy treatment and establish optimal dose distribution to reduce the chances of side effects and injury. Because there are no commercially available tools for calculating dose distribution in orthovoltage radiotherapy in companion animals, we developed an algorithm to accomplish this and verified its characteristics using tumor disease cases. First, we used the Monte Carlo method to develop an algorithm to calculate the dose distribution of orthovoltage radiotherapy (280 kVp; MBR-320, Hitachi Medical Corporation, Tokyo, Japan) using BEAMnrc at our clinic. Using development of Monte Carlo method, dose distribution for tumor and normal organs were evaluated in brain tumors, squamous cell carcinomas of the head, and feline nasal lymphomas. In all cases of brain tumors, the mean dose delivered to the GTV ranged from 36.2 to 76.1% of the prescribed dose due to the decrease through the skull. In the nasal lymphoma in cats, the eyes with covered a 2 mm-thick lead plate, the respective average dose to the eyes was 71.8% and 89.9% less than that to the uncovered eyes. The findings may be useful for informed decision making in orthovoltage radiotherapy with more effective and targeted irradiation and data collection allowing detailed informed consent.

Histiocytic sarcoma with spinal necrosis in a dog with progressing non-ambulatory tetraparesis.

Background: Histiocytic sarcoma (HS) is an aggressive malignant neoplasm, and widespread metastasis occurs with a fatal outcome. HS involving the central nervous system is relatively uncommon. Spinal cord necrosis, a very rare condition, could be induced by ischemia or infarction. Here, we report a dog progressing non-ambulatory tetraparesis with spinal cord necrosis caused by HS. Case Description: A 9-year-old male Labrador Retriever was presented with a progressing non-ambulatory tetraparesis. CT imaging revealed lysis of the spinous process of T7 and a ring-shaped lesion surrounding the soft tissue of lung fields. T2-weighted MRI showed the spinous processes of T6 to T8 as hyperintense, and the lesion infiltrated into the T7 vertebra and the spinal cord. After euthanasia, the final diagnosis upon necropsy was HS, which was observed in the lung, spinous process, thoracic cord, and the pulmonary hilar lymph node. Moreover, necrotic spots were spread widely through the thoracic spinal cord. Conclusion: This report outlines a case of canine HS in the lung, spinous process, thoracic cord, and pulmonary hilar lymph node. Ischemic deficit and necrosis of the thoracic spinal cord resulted from the compression of perivascular tumor cells, which rapidly led to progressive tetraparesis. Although the diagnosis was difficult, MRI and CT images helped determine the prognosis. To our knowledge, this is the first case report of canine HS with direct spinal cord involvement associated with spinal necrosis.

Serial MRI features of canine GM1 gangliosidosis: a possible imaging biomarker for diagnosis and progression of the disease.

GM1 gangliosidosis is a fatal neurodegenerative lysosomal storage disease caused by an autosomal recessively inherited deficiency of ß-galactosidase activity. Effective therapies need to be developed to treat the disease. In Shiba Inu dogs, one of the canine GM1 gangliosidosis models, neurological signs of the disease, including ataxia, start at approximately 5 months of age and progress until the terminal stage at 12 to 15 months of age. In the present study, serial MR images were taken of an affected dog from a model colony of GM1 gangliosidosis and 4 sporadic clinical cases demonstrating the same mutation in order to characterize the MRI features of this canine GM1 gangliosidosis. By 2 months of age at the latest and persisting until the terminal stage of the disease, the MR findings consistently displayed diffuse hyperintensity in the white matter of the entire cerebrum on T2-weighted images. In addition, brain atrophy manifested at 9 months of age and progressed thereafter. Although a definitive diagnosis depends on biochemical and genetic analyses, these MR characteristics could serve as a diagnostic marker in suspect animals with or without neurological signs. Furthermore, serial changes in MR images could be used as a biomarker to noninvasively monitor the efficacy of newly developed therapeutic strategies.

A long survival case of spinal nephroblastoma in a dog.

Background: Dogs' nephroblastoma of the spinal cord is a rare neoplastic disease, with few reports of long-term survival after surgery. We experienced that surgical treatment with postoperative radiation therapy for spinal nephroblastoma in a dog resulted in the long-term survival of 11 years. Case Description: The patient presented to our veterinary hospital because of progressive hindlimb paralysis. Based on diagnostic imaging, she was diagnosed with a thoracolumbar spinal cord tumor and was treated with surgery. The gross tumor tissue was removed after laminectomy, followed by postoperative radiation therapy using orthovoltage equipment. The histopathological features of the surgical specimen were consistent with those of previously reported spinal nephroblastoma, although infrequent mitotic figures were observed. The dog recovered well after treatment and resumed her normal walking condition. No tumor recurrence was observed on periodic follow-up magnetic resonance imaging performed 10 and 21 months after surgery. Imaging evaluation for the gradual development of hindlimb weakness was performed 9 years after surgery; however, no recurrence of tumor tissue was observed, and spondylosis deformans, probably induced after laminectomy, were identified as a possible cause. The dog died of aspiration pneumonia 11 years after surgery, independent of spinal nephroblastoma. Conclusion: To date, no clinical cases of canine spinal cord primary nephroblastoma that survived for 11 years after surgery have been reported. This case strongly suggests that providing intensive treatment for canine spinal nephroblastoma is very important.

Effect of drug-eluting bead transarterial chemoembolization loaded with cisplatin on normal dogs.

Transcatheter arterial embolization (TAE) and transcatheter arterial chemoembolization (TACE) are standard treatments for advanced hepatocellular carcinoma (HCC) and particularly for unresectable tumors or liver metastases in humans. However, reports on TACE used in veterinary medicine are few. This study aimed to evaluate the feasibility and safety of drug-eluting bead transarterial chemoembolization (DEB-TACE). We performed DEB-TACE in four clinically normal dogs and pharmacokinetically compared the results against hepatic arterial infusion (HAI) of cisplatin in two dogs. Drug-eluting beads (DEB) loaded with cisplatin were injected through a microcatheter for selective embolization of the left hepatic artery. After embolization, computed tomography (CT) images and histological examination findings were obtained during a 4-week observation period. Serum platinum concentrations were measured to evaluate cisplatin after each procedure. Biochemical analysis was performed during a 12-week observation period. Embolization was successful in all dogs, and there were no clinically apparent abnormalities. Embolization was confirmed up to 4 weeks after DEB-TACE in two of the four dogs and up to 1 week in the other two dogs using postoperative CT images. Cisplatin was not detected in peripheral veins in all dogs after DEB-TACE, but it was detected in trace amounts after HAI. DEB-TACE using cisplatin was safe and well tolerated by normal dogs. DEB-TACE may be useful in terms of determining systemic toxicity and drug concentration within tumors.

Outcomes of megavoltage radiotherapy for canine intranasal tumors and its relationship to clinical stages.

Background: Radiation therapy is considered important for the treatment of intranasal tumors in dogs and is believed to be essential for prolonging their survival. Aim: To investigate the contribution of clinical staging to improve outcomes of megavoltage radiotherapy for canine intranasal tumors. Methods: A total of 123 dogs with intranasal tumors were included in the study. Forty-eight dogs received orthovoltage radiotherapy after cytoreductive surgery (Group I), 21 received orthovoltage radiotherapy without surgery (Group II), and 54 received megavoltage radiotherapy without surgery (Group III). All cases in each group were classified into clinical stages 1-4, and the median survival time (MST) was compared for each stage in all groups. Results: The overall MST was not significantly difference among Group I (325 days), Group II (317 days), and Group III (488 days); however, Group III was prolonged than Groups I and II. The MSTs for stages 1, 2, 3, and 4 were 597, 361, 267, and 325 days in Group I; 633, 260, 233, and 329 days in Group II; and 931, 860, 368, and 176 days in Group III, respectively. The MST for stage 2 cases in Group III was significantly prolonged when compared with that in Groups I and II; no significant difference was observed at other stages; however, the MST in Group III was longer in stage 1. These results showed that megavoltage radiotherapy prolonged the MST in dogs with intranasal tumors when compared to orthovoltage radiation with or without cytoreductive surgery, and that improvements in MST at stage 2 contributed significantly to this. Conclusion: The improvement in the MST in dogs with stages 1 and 2 intranasal tumors highlights the importance of starting megavoltage radiotherapy in the early stages.