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Background: Neoadjuvant chemotherapy (NAC) is delivered before surgery to allow less extensive tumour resection, but the optimal surgical margin width after NAC is unknown. The aim of this study was to determine the impact of reassigned margins on local recurrence after NAC in dogs with mast cell tumours (MCTs)., Methods: A retrospective analysis was conducted for dogs with MCTs undergoing NAC consisting of vinblastine and prednisolone, subsequent tumour resection and lymphadenectomy, and a minimum follow-up of 6 months. Surgical margins were reassigned based on the size of the MCT after NAC. Pre- and post-NAC measurements of MCTs were recorded. The margin status was assessed with a combined radial and tangential sectioning technique; pre-NAC MCT cytograde and lymph node (LN) cytological status were compared with the Kiupel grade and Weishaar stage, respectively., Results: Twenty-two dogs were included. MCT shrinkage after NAC consistently occurred, with a median reduction rate of 40.4% (range 5%-94.5%). Margins were complete in 15 of 22 dogs, and two MCTs and three LNs appeared histologically downgraded and downstaged, respectively. Two (9.1%) MCTs recurred., Limitations: The limitations of this study were the small sample size and relatively short follow-up., Conclusion: NAC leads to shrinkage of canine MCTs, with the resulting reassigned surgical margins being associated with a low recurrence rate., (© 2024 British Veterinary Association.)

Objective: To evaluate the postoperative complication rate and local recurrence rate of apocrine gland anal sac adenocarcinoma (AGASACA) in dogs surgically treated with a modified closed anal sacculectomy technique between 2015 and 2022., Study Design: Observational clinical retrospective study., Animal Population: Forty-seven client-owned dogs histologically diagnosed with AGASACA., Methods: Medical records were evaluated for patient demographics and history, physical examination findings, diagnostic imaging, incidence of concurrent neoplasia, postoperative complications, and incidence and time to local recurrence. Dogs with at least 150 days of follow-up were included in evaluation of local recurrence., Results: Two dogs were euthanized at 4 and 11 days after surgery. Forty-five dogs were included for long-term local recurrence evaluation, with a median of 364 days of follow-up (range 156-2156 days). Only one dog (2.2%) developed local recurrence with a time to recurrence of 90 days. Postoperative complications were reported in 15 dogs (31.9%) and were considered minor in 14 dogs (93.3%) and major in one dog (6.7%). Mean survival time for the 20 dogs that were deceased as of November 1, 2022 was 521 days (range 156-1409 days) and the median survival time was 388 days., Conclusion: The modified closed anal sacculectomy technique resulted in a lower AGASACA local recurrence rate than previously reported in the veterinary literature with a comparable postoperative complication rate., Clinical Significance: Given the low recurrence rate found in this study, the modified closed anal sacculectomy technique may reduce the need for adjuvant radiation therapy and potentially chemotherapy in AGASACA patients., (© 2024 American College of Veterinary Surgeons.)

Fifteen male dogs with squamous cell carcinoma of the external genitalia were admitted for further investigation and surgical management between 1994 and 2020. The dogs belonged to various breeds. Thirteen dogs were intact and two were castrated with a median age of 8 years and a median weight of 28 kg. Seven dogs were white-coated and eight nonwhite coated. Scrotal ablation and orchiectomy were performed in four dogs, partial penile amputation in two, partial penile amputation plus partial preputial ablation in one, penile amputation, and scrotal urethrostomy in seven, and local preputial excision in one dog. Postoperative complications included hemorrhage in 10 dogs, bruising at the urethrostomy site in seven, and urethrostomy dehiscence in one dog. Tumor recurrence was recorded in six dogs. Dogs with poorly differentiated tumors that had tumor recurrence had shorter survival and worse prognosis compared to those with well and moderately differentiated tumors. The mean survival time was 48.132 months. After a median follow-up of 23 months (range: 8 to 72 months), eight dogs were alive, five were euthanized and two dogs died from unrelated causes. Surgical excision seems to be a treatment option for dogs with squamous cell carcinoma of the external genitalia., Competing Interests: Declaration of competing interest The authors of the present study declare no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Gynura procumbens , a well-known traditional herb, has been studied to be an effective chemotherapeutic agent against a wide range of cancer cell types., Case Description: A 7-year-old chihuahua dog was presented to the veterinary teaching hospital with multiple cutaneous MCT grade III masses found on the cranial aspect of the right front leg and the dorsal aspect of the neck/back. Local excision of all cutaneous tumors was performed followed by chemotherapy (vinblastine, prednisone, and cyclophosphamide) every 21-day interval for 9 treatments. Nearby 3 months later, recurrent MCT was observed and lomustine was used instead for 21-day intervals. During the first chemotherapy, the dog had a fever, weak, lethargy, and vomiting. Alternative natural therapy is preferred, the dog has been receiving G. procumbens daily. The dog responded well to this herbal treatment. These recurrent masses began to shrink after a few weeks of treatment. After several months of treatment, all masses were completely gone. Moreover, no micro-metastasis to the lungs, spleen, and liver were detected., Conclusion: This natural herbal was helpful to stop the growth of tumors, to prevent micro-metastasis, and to relieve the patient's symptoms., Competing Interests: The author declares that there is no conflict of interest.

New knowledge and data can influence the treatment options of dogs and cats affected by neoplasms. Partial limb amputation with the use of a prosthesis is possible in dogs. Newer studies attempt to define better and understand the complications and limb function associated with this approach. Limb sparing is an alternative to amputation, and three-dimensional printing allows the manufacturing of personalized endoprostheses. Finally, the recommended approach for the excision of cutaneous mast cell tumors (MCTs) is with proportional margins. In dogs, grade shifting might have occurred when removing a recurrent MCT or soft tissue sarcoma., Competing Interests: Disclosure B. Séguin has no commercial or financial conflict of interest to disclose. J.M. Liptak is on the board of QBiotics Group., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Sarcoids are common mesenchymal neoplasms of horses. Although there are few studies in which sarcoids have been followed over a long period of time, sarcoids are considered locally invasive and have been reported to frequently recur following surgical excision. Currently, no histological features have been identified to predict which sarcoids will recur after excision. The present study comprised 49 sarcoids for which histology sections were available and in which the recurrence status of the case was known. Each sarcoid was excised from a different horse. Overall, 12 of the 49 (24%) sarcoids recurred after surgical excision. Mitotic count (MC), cellularity, necrosis, nuclear pleomorphism, and inflammation of the sarcoids were evaluated histologically. Of these, MC correlated with recurrence. Four of 5 (80%) sarcoids with an MC ≥ 20 in 2.37 mm 2 recurred, which was a significantly higher recurrence rate than that of sarcoids with an MC < 20, 8 of 44 cases recurred (18%), P = .0051. Clinical type was also found to correlate with recurrence. Three of 4 (75%) fibroblastic types recurred, which was a significantly higher recurrence rate than that of sarcoids with other clinical types, 9 of 45 cases (18%), P < .001. In addition, univariate Cox regression analysis confirmed fibroblastic type and MC ≥ 20 as significant predictors for recurrence ( P = .016 and P = .005, respectively). To the authors' knowledge, this is the first large study examining recurrence rates in sarcoids, and the first time that histological features have been correlated with recurrence., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Lymphoma is a common disease in companion animals. While conventional chemotherapy has the potential to induce remission and prolong life, relapse is common and novel treatments are needed to improve outcome. This review discusses recent modifications/adjustments to conventional standard of care therapy for canine and feline lymphoma, options for treatment or relapsed/refractory disease, and cutting-edge immunotherapy and small molecule-based approaches that are in varying stages of regulatory approval., Competing Interests: Disclosure Dr D.H. Thamm is a shareholder in and has received research funding from VetDC Inc., and is a paid consultant for Elanco, the developer and current distributor of rabacfosadine (Tanovea), respectively, which is discussed in this review., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce a secondary Malassezia dermatitis, otitis externa or paronychia. Since allergic dermatitis is one of the most common underlying causes, diagnostic investigation for allergy is often indicated. Cats may suffer from various other underlying problems, especially where Malassezia dermatitis is generalised. Malassezia dermatitis in dogs and cats is chronic, relapsing and pruritic. Direct cytology from dermatological lesions and the ear canal, showing "peanut-shaped" budding yeasts, facilitates a rapid and reliable diagnosis. Topical treatment includes antiseptic and antifungal azole-based products. Systemic treatment with oral antifungals is indicated only in severe or refractory disease. Identification and treatment of the underlying cause is essential for an optimal response. In this evidence-based narrative review, we discuss the clinical presentation of Malassezia dermatitis in dogs and cats, underlying comorbidities, and diagnostic considerations. Treatment is discussed in light of emerging evidence of antifungal resistance and the authors' clinical experience., Competing Interests: Declaration of Competing Interest Ralf Mueller has been a consultant, lectured for or received support for research from the following companies manufacturing or selling antifungal medications: Ceva (topical chlorhexidine), Elanco (Malaseb shampoo, itraconazole), Selectavet (enilconazole) and Virbac (topical chlorhexidine). None of the other authors of this paper has a financial or personal relationship with other people or organizations that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Although chemotherapy using CHOP-based protocol induces remission in most cases of canine multicentric high-grade B-cell lymphoma (mhBCL), some cases develop early relapse during the first induction protocol. In this study, we examined the gene expression profiles of canine mhBCL before chemotherapy and investigated their associations with early relapse during the first whole CHOP-based protocol. Twenty-five cases of mhBCL treated with CHOP-based protocol as first induction chemotherapy were included in this study. Sixteen cases completed the first whole CHOP-based protocol without relapse (S-group), and nine developed relapse during the chemotherapy (R-group). RNA-seq was performed on samples from neoplastic lymph nodes. Differentially expressed genes (DEGs) were extracted by the comparison of gene expression profiles between S- and R-groups, and the differences in the expression levels of these genes were validated by RT-qPCR. Extracted 179 DEGs included the genes related to chemokine CC motif ligand, T-cell receptor signaling pathway, and PD-L1 expression and PD-1 checkpoint pathway. We focused on chemokine CC motif ligand, and CCL4 was confirmed to be significantly downregulated in the R-group (P=0.039). We also focused on the genes related to T-cell signaling pathway, and CD3E (P=0.039), ITK (P=0.023), and LAT (P=0.023) genes were confirmed to be significantly upregulated in the R-group. The current results suggest that both changes in tumor cells and the interactions between tumor cells and immune cells are associated with the efficacy of the chemotherapy for first remission induction.

Objectives: To describe the clinical presentation, treatment and outcomes of cats diagnosed with thymic epithelial tumours and to determine prognostic factors for survival and recurrence., Materials and Methods: Clinical records of cats diagnosed with a thymic epithelial tumour between 1999 and 2021 at three referral institutions were retrospectively reviewed., Results: Sixty-four cats were included. Paraneoplastic syndromes were present in nine cats and metastatic disease was seen in two cats, one at diagnosis and one at the time of recurrence. Median tumour diameter was 6 cm (range, 2 to 15) and a cystic appearance was described on imaging in 25 cats. Surgical excision was attempted in 54 cats with a perioperative mortality rate of 11%. Median survival time for cats surviving to hospital discharge was 897 days (range, 21 to 3322). The 1-, 2- and 5-year survival rates for surgically treated thymic epithelial tumour were 86%, 70% and 66%, respectively. Survival was longer for cats with Masaoka-Koga stage I and II tumours compared to stages III and IV (1366 days versus 454 days; P=0.002). Masaoka-Koga stage was the only significant prognostic factor detected on multi-variable analysis, with stage III and IV tumours associated with increased risk of death (hazard ratio: 5.67, 95% confidence interval: 1.29 to 24.91, P=.021). Tumour recurrence occurred in 11 cats at a median of 564 days (range, 93 to 1095); no significant prognostic factors for recurrence were identified., Clinical Significance: Cats with thymic epithelial tumours had a good long-term prognosis following surgery. Tumour recurrence can occur late in the disease course and ongoing monitoring should therefore be considered. Masaoka-Koga stage may influence survival time and could be used to predict outcome., (© 2023 The Authors. Journal of Small Animal Practice published by John Wiley & Sons Ltd on behalf of British Small Animal Veterinary Association.)

Background: Hypercalcemia of malignancy (HM) secondary to lymphoma in dogs has the potential to cause renal injury., Hypothesis/objectives: Characterize outcomes related to acute kidney injury (AKI) secondary to HM. We hypothesized that dogs do suffer AKI regardless of HM severity at the time of lymphoma diagnosis or relapse., Animals: Retrospective study. Twenty-nine dogs with lymphoma, HM, and azotemia (International Renal Interest Society [IRIS] grade II or higher AKI) that underwent chemotherapy were identified at 2 veterinary institutions., Methods: Logistic regression and descriptive statistical analysis were performed to evaluate data for potential prognostic factors., Results: After initiating treatment, resolution of hypercalcemia and azotemia occurred in 100% (29/29) and 79.3% (23/29) of dogs, respectively. Resolution of azotemia was influenced by serum creatinine concentration (odds ratio [OR], 0.148; Confidence interval [CI], 0.03-0.734; P = .02) and total hypercalcemia (OR, 0.36; CI, 0.14-0.93; P = .04) at diagnosis, whereas blood urea nitrogen concentration, IRIS grade, sex, and whether or not dogs were hospitalized were not significant factors. At data analysis, 13.8% (4/29) of dogs were alive or lost to follow-up. Of those dead, 4 dogs (15%) had renal disease at the time of death, 2/4 having concurrent lymphoma progression., Conclusions and Clinical Importance: Although AKI may be of clinical concern in dogs with HM secondary to lymphoma at diagnosis, death secondary to renal impairment appears to be infrequent., (© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Ependymal cysts represent congenital brain malformations rarely described in human medicine, where surgical resection is the treatment of choice. In veterinary medicine, only three cases have been previously reported, with one partially resected with surgery. A 6 yr old entire male American Staffordshire terrier was referred with a 4 mo history of incoordination and collapsing episodes with extensor rigidity. Neurological examination localized the lesion to the left central vestibular system and cerebellum. A brain computed tomography scan showed a hypoattenuating lesion with peripheral contrast enhancement in the fourth ventricle consistent with a cyst and secondary hydrocephalus. Treatment with prednisone was initiated, but despite an initial improvement, neurologic signs recurred and a suboccipital craniectomy to remove the cyst was performed. The cyst was first drained, and the capsule was carefully resected. The histopathological evaluation revealed a simple cubic to cylindrical epithelium with apical cilia and loose surrounding fibrillar tissue consistent with an intraventricular ependymal cyst. Four and a half years after surgery, the dog only shows short episodes of balance loss when turning abruptly but is otherwise neurologically normal. To the authors' knowledge, this is the first reported ependymal cyst in the fourth ventricle of a dog with successful surgical resection., (© 2024 by American Animal Hospital Association.)

Dogs diagnosed with multicentric lymphoma often relapse following induction therapy within the first year of treatment. The primary aim of this study was to evaluate the tolerability of a novel drug combination using melphalan, vincristine, and cytarabine (MOC) for the treatment of relapsed lymphoma. On day 1, dogs were treated with vincristine (0.5-0.6 mg/m2 IV) and cytarabine (300 mg/m2 IV over 4-6 hr or subcutaneously over 2 days). On day 7, dogs were treated with melphalan (20 mg/m2per os). This 2 wk protocol was repeated for at least three cycles or until treatment failure. Twenty-six dogs were treated with MOC and met the inclusion criteria. Twenty-three dogs had toxicity data, and all experienced adverse events with the majority graded as mild. The overall response rate was 38%, which included 19% of dogs who achieved a complete response. The median progression-free survival was 29 days (range 1-280 days). The overall clinical benefit was 65% for a median of 37 days (range 33-280 days). MOC is a safe treatment option for relapsed lymphoma in dogs., (© 2024 by American Animal Hospital Association.)

A 12-year-old spayed female American short-haired cat presented with a palatal gingival mass located between the right maxillary third incisor and the canine teeth. The mass was dark red and had a narrow attachment to the gingival margin of the canine tooth. The mass was completely removed by marginal excision and the histopathological diagnosis was a capillary hemangioma. The mass did not relapse until 1 year later; however, the tooth was extracted because of cervical resorption of the right maxillary canine immediately adjacent to the mass resection site. This report presents a rare case of the gingival hemangioma in a cat and the possibility of a causal relationship between the occurrence of external cervical tooth resorption and hemangioma resection.

Aim: This study aimed to describe the diagnosis and treatment of various surgical salivary affections in buffaloes., Materials and Methods: This study included 135 buffaloes examined at Dakahlia Governorate between 2011 and 2022 suffering from various surgical salivary affections. The recorded surgical affections had salivary fistula (n = 44), ectasia of Stenson's duct (n = 11), ranula/mucocele (n = 46), and cervical sialocele (n = 34). The buffaloes were sedated using an intramuscular injection of xylazine (0.05 mg/kg) and local infiltration analgesia of lidocaine for specific surgical interventions., Results: The salivary duct fistula cases were surgically corrected using a retrograde infusion of povidone-iodine into the duct and its double ligation with Prolene following fistulectomy. Intraoral marsupialization was done in buffaloes suffering from ectasia of the parotid duct. The mucocele /ranula was surgically incised with daily flushing with povidone-iodine. The cervical sialocele was treated by giving an elliptical excision on the sialocele, and sialoadenectomy of the mandibular salivary gland was performed to facilitate dynamic fluid/saliva drainage. A 92.5% of diseased buffaloes showed an uneventful recovery without any postoperative complications after the first treatment, whereas 7.5% of animals tended to recur. The most common and almost equally distributed salivary affections recorded in adult buffaloes were parotid duct fistula, mucocele, and cervical sialocele. The Stenson's duct ectasia was commonly registered in calves, being congenital., Conclusion: Ranula was the most common salivary affection encountered in adult buffaloes, closely followed by parotid duct fistulae and cervical sialoceles. Stenson's duct ectasia was the least encountered salivary affection in calves and was congenital. All salivary affections were corrected easily and safely, with satisfactory outcomes., (© 2023. BioMed Central Ltd., part of Springer Nature.)

The poor outcomes associated with mammary carcinomas (MCs) in dogs and cats in terms of locoregional recurrence, distant metastasis and survival, highlight the need for better management of mammary cancers in small animals. By contrast, the outcomes of women with breast cancer (BC) have dramatically improved during the last 10 years, notably thanks to new therapeutic strategies. The aim of this article was to imagine what could be the future of therapy for dogs and cats with MCs if it became inspired from current practices in human BC. This article focuses on the importance of taking into account cancer stage and cancer subtypes in therapeutic plans, on locoregional treatments (surgery, radiation therapy), new developments in endocrine therapy, chemotherapy, PARP inhibitors and immunotherapy. Ideally, multimodal treatment regimens would be chosen according to cancer stage and cancer subtypes, and according to predictive factors that are still to be defined., (© 2023 The Authors. Reproduction in Domestic Animals published by Wiley-VCH GmbH.)

Multi-agent chemotherapy successfully induces remission in most naïve, high-grade canine lymphoma patients; however, disease recurrence is common. MOPP (mechlorethamine, vincristine, procarbazine, and prednisone) is an effective rescue protocol used to re-induce remission, but is associated with gastrointestinal toxicity and can be a less desirable option for patients that previously failed vincristine-containing protocols. Therefore, alternative members of the vinca alkaloid family, such as vinblastine, could be potentially advantageous as substitutes for vincristine to reduce gastrointestinal toxicity and chemoresistance. The objective of this study was to report the clinical outcomes and toxicity of 36 dogs with relapsed or refractory multicentric lymphoma treated with a modified MOPP protocol whereby vincristine was replaced with vinblastine (MVPP). The overall response rate to MVPP was 25% with a median progression free survival of 15 days and a median overall survival of 45 days. MVPP at the prescribed doses resulted in modest and transient clinical benefit, but was well tolerated with no treatment delays or hospitalizations secondary to side effects. Given the minimal toxicity, dose intensification could be considered to improve clinical responses., (© 2023 John Wiley & Sons Ltd.)

Objective: To report the short-term and long-term outcomes of dogs that underwent the modified closed and traditional closed anal sacculectomy procedures for the treatment of anal sac neoplasia., Animals: 90 client-owned dogs., Methods: The medical records of 2 tertiary referral hospitals were reviewed to identify dogs that underwent anal sacculectomy for treatment of anal sac neoplasia between January 2016 and December 2020. Data collected included signalment and preoperative diagnostic findings. The occurrence of intraoperative and postoperative complications, short-term outcomes, and long-term outcomes were also collected. Descriptive statistics were calculated to summarize dog signalment information, and recurrence, metastasis, and survival proportions were compared between techniques using Fisher exact tests., Results: 35 and 55 dogs, respectively, underwent the modified or traditional closed anal sacculectomy procedure. Minor postoperative complications that resolved with minimal intervention occurred in 5 of 35 (14.3%) modified approach dogs and 12 of 55 (21.8%) traditional approach dogs. Tumor recurrence was confirmed in 8 of 35 (22.9%) modified and 8 of 55 (26.4%) traditional approach dogs and was suspected in 3 of 35 (8.6%) and 6 of 55 (13.2%; P = .68), respectively. Confirmed metastatic disease was identified in 8 of 35 (22.9%) and 14 of 53 (26.4%) modified and traditional approach dogs, respectively, and was suspected in 4 of 35 (11.4%) and 7 of 53 (13.2%). Sixty-three (70%) dogs survived to study conclusion., Clinical Relevance: No benefits in complication rate or local recurrence were identified in dogs following the modified approach as opposed to the traditional closed anal sacculectomy technique.

Objective: To report the short- and long-term outcomes of laparoscopic adrenalectomy (LA) for resection of unilateral adrenal masses and to document risk factors for conversion and peri- and postoperative morbidity., Animals: 255 client-owned dogs., Methods: Dogs were included if LA was attempted for resection of a unilateral adrenal mass. Medical records were evaluated and relevant data were reported, including complications, conversion, perioperative death, and long-term outcomes. Signalment, clinicopathological data, and surgical experience were factors statistically evaluated for possible associations with capsular penetration during surgery, conversion, surgical time, duration of hospital stay, death prior to discharge, mass recurrence, and survival time., Results: 155 dogs had left-sided tumors, and 100 had right-sided tumors. Conversion to an open approach was performed in 9.4% of cases. Capsular penetration (19.2%) and major hemorrhage (5.4%) were the most prevalent intraoperative complications. Of the dogs operated on, 94.9% were discharged from the hospital. Lesion side, portion of the gland affected, and surgeon experience influenced surgical time. Conversion rate increased with increasing body condition score and lesion size. Risk of death prior to discharge increased with increasing lesion size. Risk of conversion and death prior to discharge were lower when performed by more experienced surgeons. Capsular penetration during LA increased the risk of tumor recurrence., Clinical Relevance: LA for resection of unilateral adrenal masses is associated with excellent outcomes in experienced centers. Surgeons with greater experience with LA have lower surgical times, conversion rates, and risk of death prior to discharge.

Objective: To evaluate the outcome and effects of single high-dose radiation therapy with the aid of liquid fiducial markers in dogs following resection of soft tissue sarcomas (STSs)., Animals: 36 client-owned dogs., Methods: Dogs with a histologic diagnosis of a grade II or III STS that underwent liquid fiducial guided single fraction, 20-Gy stereotactic radiation therapy following surgical excision of an STS between May 2017 and March 2019 were prospectively enrolled in this study. Data collected from the medical records included patient signalment, tumor-related information, treatment details, and outcome. Kaplan-Meier survival analysis was performed for overall survival time (OST) and disease-free interval (DFI). The median OST and DFI were not reached, so restricted mean OST and DFI were also calculated., Results: 36 dogs were included in the study. All dogs underwent radiation therapy a mean of 36.1 days (range, 20 to 59 days) after surgery. Acute and delayed radiation toxicity effects occurred in 80.5% and 36.1% of dogs, respectively, all of which affected the skin. Tumor recurrence was noted in 24.3% of dogs with a median time to recurrence of 272 days (range, 14 to 843 days). The restricted mean OST was 1,556 days (range, 1,383 to 1,728 days) and restricted mean DFI was 1,330 days (range, 1,101 to 1,559 days)., Clinical Relevance: The results of this study showed that administering a single 20-Gy fraction of radiation in combination with a liquid fiducial marker to treat marginally or incompletely resected STS in the absence of gross disease resulted in similar OST and DFI compared to other previously reported radiation protocols.

Objective: To describe the management of extensive hepatectomy in 2 dogs., Animals: A 10-year-old female intact mixed-breed dog (case 1) and an 11-year-old male castrated mixed-breed dog (case 2) were presented for surgical evaluation following diagnosis of a hepatic mass., Clinical Presentation, Progression, and Procedures: 16 months before presentation, case 1 had undergone a left lateral liver lobectomy, which resulted in an incomplete resection of hepatocellular carcinoma. Both dogs underwent surgical excision of the liver mass., Treatment and Outcome: In case 1, surgery consisted of the removal of the remaining left medial lobe, as well as the central division. Case 2 received a complete left and central division hepatectomy. Histopathology confirmed a diagnosis of hepatocellular carcinoma in both dogs. Liver enzyme resolution and lack of tumor recurrence were confirmed with chemistry panel and abdominal ultrasonography in both dogs., Clinical Relevance: This case report describes, for the first time, the clinical management and outcome of extensive hepatectomy in 2 dogs. We propose that extensive hepatectomy, staged or synchronous, is possible in a clinical setting.

Objective: To prospectively evaluate clinical outcomes using acellular fish skin grafts (FSGs) for the management of complete wound healing by secondary intention after wide surgical excision of skin tumors in dogs., Animals: 5 dogs undergoing wide surgical excision of skin tumors on the distal extremity., Clinical Presentation and Procedures: FSGs were applied to surgical wound beds following wide excision of the tumor. Bandages were changed weekly and additional grafts placed when integration of the previous graft was complete. The wounds were assessed for the following: dimensions, tissue health (color), time to complete epithelialization, complications, and tumor recurrence., Results: All masses were excised with 2-cm lateral margins and 1 fascial plane deep to the tumor. Tumor diagnoses included 3 mast cell tumors and 2 soft tissue sarcomas. Surgical wounds had a median area of 27.6 cm2 (range, 17.6 to 58.7 cm2). The median number of FSG applications was 5 (range, 4 to 9 applications). Complete epithelialization occurred within 7 to 9 weeks for uncomplicated wounds (3 of 5) and 12 to 15 weeks for complicated wounds (2 of 5) that sustained self-trauma. There were no adverse events related to the use of FSGs. Local recurrence was not seen over a follow-up period ranging from 239 to 856 days., Clinical Relevance: Wide surgical excision of distal extremity skin tumors, followed by repeated application of acellular FSGs, resulted in complete healing of all wounds with no adverse events. This treatment method does not require advanced reconstructive surgical skills and may be useful for the management of skin tumors on the distal extremities.

Interleukin 2 receptor (IL-2R) is released from activated T cell lymphocytes and related to proliferation of B cells and T cells. Beta-2-microglobulin (B2M) is synthesized from all nucleated cells and constitutes a major histocompatibility complex class I antigen. In human medicine, high concentrations of these two factors have been found to be related to prognosis in aggressive non-Hodgkin's lymphoma. In this pilot study, we aimed to assess the correlation between the serum concentration of IL-2R and B2M and the diagnosis and prognosis of canine lymphoma. This study included 8 healthy dogs and 17 dogs with lymphoma. To measure the serum concentration of IL-2R and B2M, a commercial enzyme-linked immunosorbent assay was used. In dogs with lymphoma, IL-2R concentrations were significantly high at the time of diagnosis, but B2M concentrations were not. In relapsed dogs, both IL-2R and B2M concentrations were significantly higher than those in the control and chemotherapy response groups. When the serum concentrations of IL-2R and B2M during chemotherapy were monitored in four relapsed dogs, B2M levels were more closely related with relapse. This study demonstrated that serum IL-2R and B2M concentration can be a diagnostic or prognostic tool for canine lymphoma. Monitoring of serum B2M concentration seems to be useful for predicting relapse., (© 2023 John Wiley & Sons Ltd.)

Due to the complex nature of tumour biology and the integration between host tissues and molecular processes of the tumour cells, a continued reliance on the status of the microscopic cellular margin should not remain our only determinant of the success of a curative-intent surgery for patients with cancer. Based on current evidence, relying on a purely cellular focus to provide a binary indication of treatment success can provide an incomplete interpretation of potential outcome. A more holistic analysis of the cancer margin may be required. If we are to move ahead from our current situation - and allow treatment plans to be more intelligently tailored to meet the requirements of each individual tumour - we need to improve our utilisation of techniques that either improve recognition of residual tumour cells within the surgical field or enable a more comprehensive interrogation of tumour biology that identifies a risk of recurrence. In the second article in this series on defining the relevance of surgical margins, the authors discuss possible alternative strategies for margin assessment and evaluation in the canine and feline cancer patient. These strategies include considering adoption of the residual tumour classification scheme; intra-operative imaging systems including fluorescence-guided surgery, optical coherence tomography and Raman spectroscopy; molecular analysis and whole transcriptome analysis of tissues; and the development of a biologic index (nomogram). These techniques may allow evaluation of individual tumour biology and the status of the resection margin in ways that are different to our current techniques. Ultimately, these techniques seek to better define the risk of tumour recurrence following surgery and provide the surgeon and patient with more confidence in margin assessment., (© 2023 John Wiley & Sons Ltd.)

Introduction: Soft tissue sarcomas (STS) represent a heterogeneous group of tumours, with varying mesenchymal cell origin, size and histological grade. Large soft tissue sarcomas pose a surgical challenge due to feasibility of excision, and are often dismissed as good surgical candidates due to an anticipated poor prognosis., Objective: To evaluate the long-term outcome of dogs that underwent surgical excision of large (≥5 cm), low to intermediate grade, soft tissue sarcomas., Methods: Medical records of dogs that presented for STS excision between 2009 and 2021 were reviewed. Information was obtained regarding signalment, tumour location and size, preoperative cytology and histology, preoperative imaging, surgical findings, postoperative histological diagnosis and outcome. Dogs were included in the study if they underwent surgical excision of a de novo cutaneous or subcutaneous STS, which measured at least five centimeters in one plane, and was histologically diagnosed as low-intermediate grade. Long-term follow-up data were obtained via consultation, telephone or email., Results: Thirty-nine dogs with large, low-intermediate grade STS were included. Most tumours were Grade 1 (28/39), located predominantly on the thigh and thorax (17/39). Tumours were removed by at least a narrow margin excision (≥1 cm) and deep fascial plane in all cases. Histological margins were deemed complete in 15/39, close (1-3 mm) in 8/39, incomplete in 4/39, and unknown in 12/39. All sites were closed primarily, either directly (22/39) or with flap reconstruction (17/39). Long-term follow-up (median 1064 days) reported good postoperative function, with owner reported local recurrence in 2/39. Minor complications occurred in 10/39 and major complications requiring surgical intervention occurred in 5/39., Clinical Significance: Large, low-intermediate grade STSs can be surgically excised with good long-term function and outcome, where consideration is given to appropriate case selection and planning. If skin flap reconstruction is required, owners should be made aware of the possible complications associated with their use., (© 2023 The Authors. Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.)

Objective: To evaluate the clinical outcome of subcutaneous mast cell tumors (SQMCT) and to identify clinical and histological characteristics of more aggressive disease., Study Design: Retrospective study., Animals: Forty-five dogs with 48 SQMCTs., Methods: Medical records were reviewed (2011-2021) for patient information, clinical, and histopathological data including multinucleation, necrosis, invasion into local muscle, an infiltrative growth pattern, tumor grade (if listed), mitotic index, and surgical margins. The presence of local recurrence, lymph node metastasis, survival time, and other parameters evaluating patient outcome were also recorded., Results: Local recurrence occurred in 17.8% (8/45) of dogs, 11.1% (5/45) developed metastatic recurrence, and 26.7% (12/45) developed lymph node metastasis. Dogs with lymph node metastases had a median disease-free interval (DFI) of 194 days (18-1864), while median DFI was not reached for dogs without lymph node metastasis (p = .0012). Median survival time for dogs with lymph node metastasis was 551 days (110-2050) compared to 1722 days (10-1722) without metastasis (p = .0432). Local recurrence resulted in a significantly shorter median survival time of 551 days (80-2050) compared to 1722 days (10-1722) for dogs without local recurrence (p = .0038). Dogs with infiltrative tumors had a median DFI of 268 days (3-1722) and DFI for dogs without an infiltrative pattern had not reached median at 1864 days (10-1864) (p = .011)., Conclusion: Lymph node metastasis decreased disease-free interval and survival., Clinical Significance: Subcutaneous mast cell tumors may be a more aggressive disease than previously reported., (© 2023 American College of Veterinary Surgeons.)

Recurrent otitis externa is a common problem in dogs. Topical treatment for each flare is successful in the short term, but repeated cycles of inflammation and infection lead to chronic inflammatory changes, pain and aversion, and antimicrobial resistance. These make the flares more frequent and harder to control. Eventually, the changes become irreversible and require a total ear canal ablation/lateral bulla osteotomy or ablative laser surgery. Most ear canal surgery is avoidable if recurrent otitis is properly managed at an earlier stage. This requires a different mindset and approach to these cases, taking advantage of recent research and clinical findings. Most importantly, clinicians must appreciate that all recurrent ear infections in dogs are secondary. To achieve a good long-term outcome, it is essential that all the underlying factors in each case are diagnosed and managed using the primary, secondary, predisposing, and perpetuating framework. This means that the primary condition must be diagnosed and managed, the secondary infection treated, predisposing risks identified and corrected, and the perpetuating factors reversed. Treatment is in 2 phases: induction to get the ears in remission and then long-term maintenance therapy to prevent relapses. Treatment should be appropriate to each dog but will typically involve ear cleaning, topical antimicrobial therapy, and topical or systemic glucocorticoids. Novel treatments for infection and inflammation will offer additional options in the future. Understanding the triggers for recurrent otitis in dogs will help clinicians plan effective management regimens that will make a huge difference to the quality of life of their patients and their owners.

The goal of cancer surgery is to achieve a "clean" microscopic resection, with no residual tumour remaining in the wound. To achieve that goal, the surgeon typically incorporates a measured buffer of grossly normal tissue about the entire circumference of the tumour. Microscopic analysis of the resection boundaries is then performed to determine if all traces of the tumour have been completely removed. This analysis is thought to provide a surrogate indication as to the likelihood for that tumour to recur after surgery. However, it is recognised that tumour recurrence may not occur even when microscopic evidence of tumour has been identified at the resection margins, and recurrence can also occur when conventional histology has considered the tumour to have been completely removed. The explanations for this dichotomy are numerous and include technical and practical limitations of the processing methodology, and also several surgeon-related and tumour-related reasons. Ultimately, the inability to confidently determine when a tumour has been removed sufficiently to prevent recurrence can impact on the ability to provide owners with confident treatment advice. In this article, the authors describe the challenges with defining the true extent of the tumour margin from the perspective of the surgeon, the pathologist and the tumour. The authors also provide an analysis of why our current efforts to ensure that all traces of the local tumour have been successfully removed may provide an imperfect assessment of the risk of recurrence., (© 2022 John Wiley & Sons Ltd.)

Background: Canine mammary tumors (CMTs) have a poor prognosis, along with tumor recurrence and metastasis. Cell lines are vital in vitro models for CMT research. Many CMT epithelial cell lines were reported. However, canine mammary myoepithelial cells, the contractile component of the canine mammary tissue were overlooked. This study aimed at establishing such a cell line. CMT-1 cell line was obtained from a canine mammary tumor CMT-1 and characterized molecularly through qPCR, western blotting, immunochemistry and immunofluorescence. Its doubling time, cytogenetic analysis and migration rate were evaluated using growth study, karyotype analysis and wound healing assay respectively. To determine its tumorigenesis, xenograft transplantation was performed., Results: CMT-1 tumor was a complex canine mammary carcinoma that stained negative to estrogen receptors (ER) and progesterone receptors (PR), but positive to human epidermal growth receptor-2 (HER2), defined as HER2-enriched subtype. In this study, a CMT-1 cell line obtained from CMT-1 tumor was immune-positive to vimentin, α-SMA, p63 and negative to E-cadherin (E-cad), indicating CMT-1 cells were myoepithelial cells. It was successfully cultured for more than 50 passages showing the same immunoreactivity to ER, PR, and HER2 as the primary canine tumor. The doubling time of CMT-1 cell line was 26.67 h. The chromosome number of CMT-1 cells ranged from 31 to 64. A potential spontaneous epithelial to mesenchymal transition (EMT) was noticed during cell cultures. Potential EMT-induced CMT-1 cells showed no significance in migration rate compared to the original CMT-1 cells. CMT-1 cells was able to grow on a 3D culture and formed grape-like, solid, and cystic mammospheres at different time period. Inoculation of CMT-1 cells induced a complex HER2-enriched mammary tumor with metastasis in mice., Conclusions: A canine cancerous HER2-enriched myoepithelial cell line was successfully established and a canine mammosphere developed from myoepithelial cells was documented in this study. We are expecting this novel cell line and its associated mammospheres could be used as a model to elucidate the role of myoepithelial cells in CMT carcinogensis in the future., (© 2023. The Author(s).)

Objective: Describe clinical features and outcomes of dogs undergoing scar revision for incompletely or narrowly excised cutaneous mast cell tumors without gross disease., Animals: 52 dogs undergoing 54 scar revisions., Procedures: Retrospective record review with information collected on signalment, tumor type/location, pre-surgical diagnostics, surgical and pathologic findings for the first excision and scar revision surgeries, and follow-up. Descriptive statistics were generated., Results: Prior to initial excision, cytology was performed on 38.9% (21/54) of tumors and the initial surgery report rarely described surgical resection margins [14.6% (7/48) of surgeries]. Residual tumor was identified pathologically in 29.6% (16/54) of scars. Local recurrence following scar revision occurred in 3.7% (2/54) of all scars [median follow-up 881.5 d (range: 0 to 3317 d)]; both scars had either complete excision of residual mast cell tumor or no evidence of mast cell tumor on scar revision and neither dog received radiation therapy., Conclusions: Identification of residual disease was uncommon, and local recurrence was less common than previously reported for incomplete/narrow mast cell tumor excision., Clinical Relevance: Scar revision of unplanned primary excisions appears to yield a high likelihood of durable tumor remission in patients. First opinion practitioners are encouraged to avoid unplanned excisions by informing the surgical plan with cytology of the primary tumor and detailing surgical margin excision which may facilitate revision, if necessary., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Objective: Describe clinical features of dogs undergoing scar revision for incompletely or narrowly excised soft tissue sarcomas (STSs) in the absence of gross disease and to determine local recurrence rates following scar revision., Animals: Thirty-three dogs with 33 scars., Procedures: Medical records were reviewed to collect data on signalment, tumor details, pre-surgical diagnostic tests, surgical and pathologic findings for both the initial and revision surgeries, and clinical outcomes. Descriptive statistics were generated., Results: For the initial excision, cytology was performed before surgery in 45.5% (15/33) of dogs, and information on surgical margins was rarely reported [4.0% (1/25) of circumferential and 12.0% (3/25) of deep margins]. Microscopic evidence of residual STS was identified in 18.2% of scars. Recurrence occurred in 3.0% (1/33) of dogs [median follow-up of 1127 d (1 to 3192 d)]; this dog had had no evidence of residual tumor in the scar revision pathology., Conclusions: Despite the low identification rate of residual tumor, the local tumor recurrence rate was 3.0%, which is lower than what is historically reported for incompletely or narrowly excised STSs., Clinical Relevance: Scar revision for incompletely or narrowly excised STSs resulted in durable tumor remission in the dogs of this study. Pre-surgical diagnostic tests were not often performed in this study; these may be considered before the first excision to plan surgical margins for potentially reducing the incidence of incomplete or narrow excision. Surgical reports should include details on circumferential and deep margins to guide pathologic interpretation and future scar revision, if required., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

A 7-year-old intact female domestic medium hair cat was examined at a veterinary clinic for a scabbed nodule over the right shoulder. Multiple nodules recurred at the same site after the first surgical excision, and a second surgical excision was performed. Histopathology demonstrated high-mitotic-rate neoplastic cells and therefore a histiocytic proliferative disease was initially suspected. The condition progressed rapidly within a 5-month period and the cat was euthanized due to sudden onset of severe dyspnea. Necropsy showed diffuse metastatic nodules in the lungs, confirming a histiocytic proliferative disease, with histiocytic sarcoma being the most likely differential diagnosis., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Autologous peripheral blood haematopoietic stem cell transplantation (HCT) cures 33%-40% of dogs with high-grade B-cell lymphoma. We hypothesized, based on human allogeneic bone marrow transplantation literature, that transplanting dogs using canine donor leukocyte-matched CD34+ cells would lead to fewer relapses and increased cure rates. We retrospectively reviewed medical records of dogs diagnosed with high-grade B-cell lymphoma who received an identical allogeneic HCT. A total of 15 dogs transplanted at four facilities were identified. Five of fifteen dogs relapsed before transplant. The mean number of donor CD34+ cells/kg harvested and infused into recipient dogs was 8.0 × 10 6 /kg (range: 2.08 × 10 6 /kg-2.9 × 10 7 /kg). The median disease-free interval and overall survival of all dogs was 1095 days (range: 9-2920 days) and 1115 days (range: 9-2920 days), respectively. Two of five dogs, not in remission at transplant, died in the hospital. The median disease-free interval and overall survival of the remaining three dogs was 25 days (range: 15-250 days) and 1100 days (range: 66-1902 days), respectively. The median disease-free interval and overall survival of the 10 dogs who had not relapsed was 1235 days (range: 19-2920 days) and 1235 days (range: 19-2920 days), respectively. One dog died soon after discharge of presumed gastric-dilatation-volvulus. Eight of nine remaining dogs lived >4 yrs post-alloHCT, leading to a cure rate of 89%. Acute graft versus host disease was seen in three dogs. These results suggest that allogeneic HCT can cure ~50% more dogs than those treated with autologous HCT., (© 2022 The Authors. Veterinary and Comparative Oncology published by John Wiley & Sons Ltd.)

Background: Multiple myeloma (MM) is an uncommon neoplasm in cats. There is no established standard of treatment due to the rare occurrence of this disease in cats. Bortezomib is a proteasome inhibitor that serves as the first-line drug for MM in humans, but its effectiveness currently is unknown in feline MM. We present here the case report of a feline MM that exhibited a favorable response to bortezomib., Case Presentation: The case was an 11-year-old non-castrated male domestic cat with light-chain MM presenting with clinical symptoms (anorexia, fatigue, and vomiting), mild azotemia, and pancytopenia. The cat failed on melphalan with prednisolone (MP), so bortezomib (Velcade) was initiated on Day 88. A total of 6 cycles of the treatment was performed, with each treatment cycle consisting of twice-weekly subcutaneous administration for 2 weeks followed by a 1-week rest. The dose of bortezomib was 0.7 mg/m 2 for first week and 1.0 mg/m 2 for second week in the first cycle. A dose of 0.7 mg/m 2 was used for subsequent cycles. Prednisolone was used concomitantly in the first 2 cycles. Following treatment with bortezomib, clinical symptoms disappeared and a decrease in serum globulin and recovery of pancytopenia were noted. A monoclonal gammopathy, overproduction of serum immunoglobulin light chain, and Bence-Jones proteinuria that existed at diagnosis were undetectable on Day 123. A monoclonal gammopathy also was not detectable at the end of the bortezomib treatment (Day 213). Anorexia, fatigue, and marked bone marrow toxicity were experienced when bortezomib was administrated at a dose of 1.0 mg/m 2 , while no recognizable toxicity was observed at a dose of 0.7 mg/m 2 throughout the treatment period. The case was placed on follow-up and there was no evidence of relapse as of Day 243., Conclusions: Bortezomib was effective and durable for the treatment of this case of feline MM after failure with MP. Bortezomib was well-tolerated in this cat at a dose of 0.7 mg/m 2 , but not at 1.0 mg/m 2 . Bortezomib appears to be a drug worthy of further study for the treatment of feline MM., (© 2022. The Author(s).)

Objective: To describe the frequency of incomplete histological margins following planned narrow excision (PNE) of mast cell tumors (MCTs) and soft tissue sarcomas (STSs), and to assess the residual tumor classification (R) scheme for reporting histological margins in clinical cases., Study Design: Retrospective clinical study., Sample Population: Forty-four client-owned dogs with 47 masses., Methods: Medical records of dogs undergoing planned narrow excision of STSs and MCTs were reviewed (2016-2019). Histologic specimens were reviewed by a single pathologist and assigned R scoring (histologically incomplete/R1 margins defined as "tumor on ink")., Results: Six out of 23 (26%) MCT PNEs and 10/42 (42%) of STS PNEs resulted in R1 margins. R1 margins were more likely when performing PNE with 6-10 mm lateral measured surgical margins (LMSMs) versus 0-5 mm LMSM for MCTs (1/14 vs 5/9), but not STSs (3/7 vs 7/17) (P = .049). The R scheme resulted in higher retrospective percentage agreement in histological reporting than defining incomplete histological margin as tumor cells within ≤1 mm of the margin (83% vs 68% agreement). Complications occurred in 12/47 surgeries, with none requiring additional surgery. Tumors recurred in 3/18 (17%) STSs and 2/18 (11%) MCTs., Conclusion: Fewer R1 margins were obtained when PNE with LMSM of 6-10 mm was performed for mast cell tumors. The use of the R scheme increased agreement in histopathological margin assessment., Clinical Significance: Planned narrow excision is a viable technique for histopathological diagnosis of appendicular soft tissue sarcomas and mast cell tumors for limb salvage., (© 2022 American College of Veterinary Surgeons.)

Local recurrence after surgical excision of canine massive hepatocellular carcinoma (HCC) has been poorly studied in veterinary medicine with scant information published regarding risk factors for and outcome following recurrence. The aim of this case-control study was to describe the time to recurrence, evaluate potential risk factors for recurrence, and report the outcome in dogs with massive HCC. Medical records for 75 dogs who developed recurrence and 113 dogs who did not develop recurrence were reviewed. Statistical analyses were performed to determine risk factors for recurrence as well as the median time to develop recurrence and overall survival time (OS). None of the risk factors evaluated were significant for the development of recurrence. The median time to develop recurrence was 367 days (range 32-2096 days). There was no significant difference in median OS for dogs who developed recurrence vs. those who did not (851 vs. 970 days). For dogs with recurrent HCC, treatment at recurrence trended toward prolonged OS but was not significantly different from dogs not undergoing treatment at recurrence. There was no significant difference in median OS for dogs with histologically complete vs. incomplete tumour excision (990 vs. 903 days). Although specific risk factors for recurrence were not identified, elevations in liver values were noted in patients with recurrent disease and could act as a noninvasive surveillance tool. Recurrence was noted earlier in dogs who had routine post-operative surveillance (228 vs. 367 days). Routine surveillance for recurrence is recommended especially in dogs where further intervention is possible and should extend beyond 1 year. Patients with massive HCC have a good long-term prognosis regardless of incomplete excision, pulmonary metastasis, or recurrent local disease., (© 2022 The Authors. Veterinary and Comparative Oncology published by John Wiley & Sons Ltd.)

Rhabdoid meningioma is a rare type of meningeal neoplasm in humans. This study reports the clinical, pathological, and ultrastructural features of 4 cases of canine meningioma with rhabdoid features. The cases were female and 8 to 12 years of age. Biopsies from complete surgical resections were examined for all cases. The whole brain with tumor recurrence was collected at necropsy in 2 dogs. Histologically, the tumors consisted of discohesive sheets of oval-polygonal cells with abundant eosinophilic cytoplasm and occasional paranuclear hyaline-like inclusions. Cells were intensely immunopositive for vimentin, negative for melan A and S100 protein in all cases, and showed variable immunolabeling for cytokeratin in 2 cases. Focal glial fibrillary acidic protein (GFAP)-immunopositive cells were present in 1 case. Ultrastructurally, the rhabdoid cells in case 1 contained prominent cytoplasmic whorls of intermediate filaments, recapitulating the ultrastructural features of rhabdoid meningioma in humans. In cases 2 and 3, the meningioma cells contained interdigitating cell processes folded in a maze-like fashion resembling rhabdoid-like meningioma in humans. In case 4, the voluminous cytoplasm contained many round-to-flattened mitochondria admixed with rough endoplasmic reticulum, indicating a predominant oncocytic differentiation and not the rhabdoid differentiation suggested by light microscopy. Thus, rhabdoid morphology occurs in different types of meningiomas, and ultrastructural findings are essential for a correct diagnosis.

Objective: To report the surgical treatment of a canine with both ankylosis and pseudoankylosis of temporomandibular joint (TMJ). Methods: The patient presented for inability to open his mouth. Facial asymmetry with normal dental occlusion was appreciated and computed tomography (CT) was performed. CT was used to diagnose ankylsosis and pseudoankylosis of left TMJ secondary to chronic maxillofacial trauma. A gap arthroplasty followed by interpositional arthroplasty using temporalis muscle fascia was performed to remove the site of fusion and prevent re-ankylosis between remaining cut boney surfaces. A three-dimensional (3D) printed skull for surgical planning and intraoperative spatial localization was employed. Results: Following preoperative and intraoperative evaluation of the 3D printed skull, the surgery was performed successfully without major complications. The patient's TMJ range of motion was markedly improved and remains improved as noted by inter-incisal distance measurements, ability to pant, and ease of chewing. Conclusion: A combined Gap and interpositional arthroplasty was assisted with the use of a 3D printed skull and immediately resulted in improved TMJ range of motion and patient quality of life. Three-month postoperative CT revealed stable ostectomies with no complications, with the exception of left-sided disuse masticatory muscle atrophy. Long-term follow-up is warranted. Clinical Significance: Three-dimensional printed skull models may be utilized preoperatively and intraoperatively to determine individual variants and landmarks, especially in cases where anatomical structures are difficult to recognize. Gap arthroplasty with interpositional myofascial transposition is an option for a patient with both anklyosis and pseudoankylosis of the TMJ.

The aim of this study was to determine the outcome of dogs with soft tissue sarcoma (STS) within the region of the ischiatic tuberosity (ITSTS) treated surgically. This was a multi-institutional retrospective study. Fifty-two dogs met the inclusion criteria, which were: histologically confirmed STS in the region of the IT treated with surgical resection between March 1st, 2009 and March 1st, 2021 with a minimum follow-up time of 6 months. Data collected included patient signalment, preoperative diagnostics, surgical intent/method, surgical complications, histopathology, margins, outcome and cause of death. Statistical analyses were performed to determine significant factors in the treatment and prognosis of ITSTS. Overall survival time (OST) and disease progression were negatively associated with tumour grade, while recurrence was positively associated with grade and incomplete margins. Of the 52 included dogs, there were 24 grade I, 20 grade II and 7 grade III tumours. Forty dogs had reported histopathologic margins of which 26 were reported to be complete and 14 were incomplete. OST and progression-free survival was not reached for tumours graded as I or II and was 255 and 268 days respectively, for grade III. Median time to recurrence was not reached for tumours excised with complete margins and was 398 days for those with incomplete margins. The surgical complication rate was 25%. ITSTS was not found to be a unique clinical entity in dogs as tumour behavior, treatment recommendations, and prognosis were similar to STS in other locations, with overall outcome and prognosis influenced by histologic grade and margins. While surgical complications were common, none resulted in significant morbidity or mortality., (© 2022 John Wiley & Sons Ltd.)

Objectives: To report the surgical techniques being used to treat single focal spinal intra-arachnoid diverticula in dogs, their complications and immediate postoperative outcomes., Materials and Methods: Retrospective multi-centre case series across four referral centres., Results: Fifty-seven dogs were included in the study. The most common type of surgery was durectomy (28 dogs) followed by marsupialisation (11 dogs), durotomy alone (seven dogs), shunt placement (six dogs) and stabilisation (five dogs). A higher proportion of intra-arachnoid shunt dogs became unable to walk in the immediate postoperative period (24 hours postsurgery) (4/6, 66%) compared to all dogs five of 57, 9% (2/7 durotomy alone, 3/28 durectomy alone). Of the nine dogs with immediate postoperative deterioration, seven had improved, walking without assistance, by 3 to 5 weeks postoperatively., Clinical Significance: This study does not identify an influence of surgical technique on short-term outcome. Dogs with a thoracolumbar intra-arachnoid diverticulum that undergo a shunt placement are likely to deteriorate neurologically in the immediate 24-hour postoperative period but appear to improve by 3 to 5 weeks after surgery. Further work is required to evaluate whether one surgical technique is superior for preventing or reducing long-term relapse., (© 2022 The Authors. Journal of Small Animal Practice published by John Wiley & Sons Ltd on behalf of British Small Animal Veterinary Association.)

No uniformly beneficial treatments exist for dogs with non-lymphomatous nasal tumours (NLNT) that relapse after radiotherapy (RT). Reirradiation may prolong survival and improve quality of life. In this retrospective study, we describe outcomes for 11 dogs that had CT-confirmed locoregional progression of NLNT after an initial course of stereotactic RT (SRT#1; 10 Gy × 3) and were then re-treated with the same type of protocol (SRT#2, also 10 Gy × 3). The median time between SRT #1 and SRT #2 was 243 days (95% CI: 78-385 days). Ten dogs (91%) had a clinical benefit after SRT#1; five dogs (45%) had clinical benefit after SRT#2. Adverse events after SRT#2 included nasocutaneous or oronasal fistula formation (N = 3 at 180, 270, and 468 days), seizures (N = 2 at 78 and 330 days), bacterial or fungal rhinitis (N = 2 at 240 and 385 days), and facial swelling (N = 1 at 90 days). All 11 dogs have died, due to disease progression, presumed radiotoxicity, or declining quality of life; in most cases, it was difficult to discern between these conditions. The median overall survival time (OST) from SRT#1 was 745 days (95% CI: 360-1132). The median overall survival time (OST) from SRT #2 was 448 days (95% CI: 112-626). For these dogs, survival was prolonged, but adverse events after SRT#2 were common (8/11; 73%). Therefore, before consenting to re-irradiation with this protocol, pet owners should be counselled about survivorship challenges, including risk for severe toxicities, and persistence of clinical signs., (© 2022 The Authors. Veterinary and Comparative Oncology published by John Wiley & Sons Ltd.)