Retrospective Study Evaluating Surgical Treatment and Outcome in Dogs with Septic Peritonitis Secondary to Neoplasia.

Septic peritonitis is a life-threatening disease that can be caused by neoplasia, among other disease processes. There is no veterinary literature directly evaluating the outcome of patients with septic peritonitis caused by neoplasia. The objective of this study was to evaluate for differences in survival to discharge and complication rates between septic peritonitis caused by neoplastic and nonneoplastic disease in canine patients. A single-institution retrospective cross-sectional cohort study was performed, identifying dogs that were treated surgically for septic peritonitis between January 1, 2010, and November 1, 2020. A total of 86 patients were included, 12 with a neoplastic cause for septic peritonitis and 74 with another cause. The most common neoplastic lesions associated with septic peritonitis were gastrointestinal lymphoma and hepatocellular adenoma. Presence of neoplasia was not a significant factor for development of intraoperative or immediate postoperative complications, nor did it decrease chances of survival to discharge (P < .09). The diagnosis of a primary, localized, neoplastic lesion alone should not deter clinicians and owners from pursuing treatment for septic peritonitis.

Multilobular tumor of bone arising from the palatomaxillary suture line in the skull of a dog.

A 6-year-old neutered male bloodhound dog was presented for surgical evaluation of an intraoral hard palate mass noted during a routine dental cleaning performed by the primary veterinarian. Computed tomography (CT) of the skull revealed a well-defined, multilobular, mineralized mass with a coarse, granular appearance, centered along the palatomaxillary suture extending into both the nasal and oral cavities. Bilateral caudal maxillectomy was performed for curative-intent resection of the tumor. The histopathology of the mass was consistent with a completely excised palatomaxillary multilobular tumor of bone (MLTB). This is apparently the 1st successful report of surgical excision of an MLTB associated with the palatomaxillary suture line. Key clinical message: Our findings emphasized that MLTB should be considered as a differential diagnosis for masses arising in the location of cranial sutures, and a definitive diagnosis can be made postoperatively with histopathology of the mass.

Tumeur osseuse multi-lobulaire résultant de la ligne de suture palato-maxillaire dans le crâne d'un chien. Un chien Saint-Hubert mâle castré de 6 ans a été présenté pour évaluation chirurgicale d'une masse intrabuccale du palais dur notée lors d'un nettoyage dentaire de routine effectué par le vétérinaire initial. La tomodensitométrie (CT) du crâne a révélé une masse minéralisée multi-lobulaire bien définie avec un aspect grossier et granuleux, centrée le long de la suture palato-maxillaire s'étendant dans les cavités nasale et buccale. Une maxillectomie caudale bilatérale a été réalisée pour une résection à visée curative de la tumeur. L'histopathologie de la masse était compatible avec une tumeur osseuse multi-lobulaire palato-maxillaire complètement excisée (MLTB). Il s'agit apparemment du premier rapport réussi d'excision chirurgicale d'une MLTB associé à la ligne de suture palato-maxillaire.Message clinique clé :Nos résultats ont souligné que la MLTB doit être considérée comme un diagnostic différentiel pour les masses apparaissant à l'emplacement des sutures crâniennes, et un diagnostic définitif peut être posé en postopératoire avec l'histopathologie de la masse.(Traduit par Dr Serge Messier).

Metastatic carcinoma of unknown origin in a dog.

Although cancer of unknown primary origin (CUP) is well-described in the human literature, it is not as well-understood within veterinary medicine. This case report represents one of few focused on describing CUP in a dog. Key clinical message: Metastatic CUP should be considered as a differential diagnosis despite being a rare disease entity that is infrequently reported within the veterinary literature.

Carcinome métastatique d'origine inconnue chez un chien. Bien que le cancer d'origine primaire inconnue (CUP) soit bien décrit dans la littérature humaine, il n'est pas aussi bien compris en médecine vétérinaire. Ce rapport de cas représente l'un des rares à s'intéresser à la description du CUP chez un chien.Message clinique clé:Le CUP métastatique doit être considéré comme un diagnostic différentiel bien qu'il s'agisse d'une entité de maladie rare rarement rapportée dans la littérature vétérinaire.(Traduit par Dr Serge Messier).

Utility of Spleen and Liver Cytology in Staging of Canine Mast Cell Tumors.

Abdominal ultrasound with spleen and liver cytology is part of routine staging for canine mast cell tumors (MCTs). However, such tests are associated with increased morbidity and cost. Therefore, the objectives of this study were to determine if spleen cytology was predictive of liver cytology in canine MCTs and if any patient or tumor variables were associated with spleen and/or liver metastasis. Records of dogs with MCTs and cytology of spleen and liver were reviewed. Two hundred five patients were included. Overall, 22 (10.7%) patients had metastasis, with 21 (10.2%) and 13 (6.3%) having spleen and liver metastasis, respectively, and 12 (5.9%) having both. For patients with a positive (or negative) spleen cytology, the odds ratio of having a positive (or negative) liver cytology was 233.49. However, a negative spleen cytology had a higher predictive value (0.99) than a positive cytology (0.54). Finally, the presence of local and systemic signs and tumor size were associated with spleen, liver, and/or spleen or liver metastasis. These results suggest that spleen cytology is predictive of liver cytology in staging of canine MCTs, and increasing tumor size and presence of local or systemic signs are associated with an increased risk of visceral metastasis.

Veterinary student urethral catheterization of small female cats and dogs using 2 urethral catheterization techniques.

Objective: Compare veterinary student success at urethral catheterization of small female cats and dogs using traditional and novel 2-catheter techniques. Animal: Healthy anesthetized female cats (n = 23) and dogs (n = 6) weighing < 10 kg undergoing elective ovariohysterectomy. Procedure: Two junior (Year 3) veterinary students with no previous urethral catheterization experience participated. Each pet was catheterized by 1 student using both the traditional blind technique and the novel 2-catheter method (placement of a large red rubber catheter into the vaginal canal prior to insertion of the conventional catheter). Technique order was randomized and attempts for each technique was allowed for up to 3 min. Time to successful catheterization and catheterization success within the allotted time were recorded. Results: Successful urethral catheterization was performed using the traditional blind and novel 2-catheter techniques in 56.3 and 87.5% of cases, respectively. Conclusion: Students had a higher rate of successful catheterization with the 2-catheter catheterization technique in this report. Clinical relevance: Urethral catheterization in small female cats and dogs is technically challenging, which is compounded by the inability to consistently and reliably palpate loco-regional anatomic landmarks due to the small sized vestibules. Data from this report will be used to design future studies to assess the utility of this novel urethral catheterization technique for teaching inexperienced students this challenging clinical skill.

Résumé. Objectif: Comparez le succès des étudiants vétérinaires lors du cathétérisme urétral de petites chattes et chiennes en utilisant des techniques traditionnelles et nouvelles à deux cathéters. Animal: Chattes (n = 23) et chiennes (n = 6) en bonne santé et anesthésiées pesant < 10 kg subissant une ovariohystérectomie élective. Procédure: Deux étudiants vétérinaires juniors (3e année) sans expérience préalable en cathétérisme urétral ont participé. Chaque animal a été cathétérisé par un étudiant en utilisant à la fois la technique traditionnelle à l'aveugle et la nouvelle méthode à deux cathéters (placement d'un gros cathéter en caoutchouc rouge dans le canal vaginal avant l'insertion du cathéter conventionnel). L'ordre des techniques a été randomisé et les tentatives pour chaque technique ont été autorisées jusqu'à 3 minutes. Le temps de cathétérisme réussi et le succès du cathétérisme dans le temps accordé ont été enregistrés. Résultats: Un cathétérisme urétral réussi a été réalisé en utilisant les techniques traditionnelles à l'aveugle et les nouvelles techniques à deux cathéters dans 56,3 et 87,5 % des cas, respectivement. Conclusion: Les étudiants avaient un taux plus élevé de cathétérisme réussi avec la technique de cathétérisme à deux cathéters dans ce rapport. Pertinence clinique: Le cathétérisme urétral chez les petites chattes et chiennes est techniquement difficile, ce qui est aggravé par l'incapacité de palper de manière cohérente et fiable les repères anatomiques loco-régionaux en raison des vestibules de petite taille. Les données de ce rapport seront utilisées pour concevoir de futures études afin d'évaluer l'utilité de cette nouvelle technique de cathétérisme urétral pour enseigner aux étudiants inexpérimentés cette habileté clinique difficile.(Traduit par Dr Serge Messier).

Complications associated with iliosacral lymphadenectomy in dogs with metastatic apocrine gland anal sac adenocarcinoma.

Objective: To report intraoperative and immediate postoperative complications associated with removal of metastatic iliosacral lymph nodes in dogs with apocrine gland anal sac adenocarcinoma. Animals: There were 136 client-owned dogs in the study. Procedure: Retrospective multi-institutional study. The database of collaborating institutions was searched for dogs with metastatic apocrine gland anal sac adenocarcinoma that underwent lymphadenectomy for removal of one or more iliosacral lymph nodes. Information of signalment, hematological abnormalities, abdominal computed tomography or ultrasound findings, number and size of enlarged lymph nodes, intraoperative and postoperative complications, treatment and outcome were collected. Results: The overall complication rate associated with metastatic iliosacral lymphadenectomy was 26.1%. The only intraoperative complication recorded was hemorrhage and was reported in 24 (17.6%) surgeries, 11 (45.8%) of which received a blood transfusion. Postoperative complications were reported in 10.4% of surgeries, and included edema formation (n = 4, 2.6%), unilateral or bilateral paraparesis (n = 4, 2.6%), hypotension (n = 3, 2.0%), surgical site infection (n = 2, 1.3%), abdominal incision dehiscence (n = 1, 0.6%), urinary incontinence (n = 1, 0.6%), and death (n = 1, 0.6%). The size of the iliosacral lymph nodes was significantly associated with a greater risk of complications, hemorrhage, and the need of transfusion during lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma. Conclusion: Complications associated with iliosacral lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma are relatively common and mostly relate to hemorrhage. These complications are significantly associated with the size of the extirpated metastatic lymph nodes. Clinical relevance: This retrospective study provides information for the clinician regarding the potential surgical complications for extirpation of metastatic iliosacral lymph nodes. These complications, although not common, can be severe and should be discussed with owners before surgery.

Objectif: Rapporter les complications peropératoires et postopératoires immédiates associées à l'ablation des ganglions lymphatiques ilio-sacrés métastatiques chez les chiens atteints d'un adénocarcinome des glandes apocrines des sacs anaux. Animaux: Il y avait 136 chiens appartenant à des clients dans l'étude. Procédure: Étude multi-institutionnelle rétrospective. La base de données des institutions collaboratrices a été recherchée pour les chiens atteints d'un adénocarcinome métastatique des glandes apocrines des sacs anaux qui ont subi une lymphadénectomie pour l'ablation d'un ou plusieurs ganglions lymphatiques ilio-sacrés. Des informations sur le signalement, les anomalies hématologiques, les résultats de la tomodensitométrie abdominale ou de l'échographie, le nombre et la taille des ganglions élargis, les complications peropératoires et postopératoires, le traitement et les résultats ont été recueillis. Résultats: Le taux global de complications associées à la lymphadénectomie ilio-sacrée métastatique était de 26,1 %. La seule complication peropératoire enregistrée était une hémorragie et a été rapportée dans 24 (17,6 %) chirurgies, dont 11 (45,8 %) ont reçu une transfusion sanguine. Des complications postopératoires ont été signalées dans 10,4 % des interventions chirurgicales et comprenaient la formation d'oedème (n = 4, 2,6 %), la paraparésie unilatérale ou bilatérale (n = 4, 2,6 %), l'hypotension (n = 3, 2,0 %), l'infection du site opératoire (n = 2, 1,3 %), la déhiscence de l'incision abdominale (n = 1, 0,6 %), l'incontinence urinaire (n = 1, 0,6 %) et le décès (n = 1, 0,6 %). La taille des ganglions ilio-sacrés était significativement associée à un risque accru de complications, d'hémorragie et à la nécessité d'une transfusion lors d'une lymphadénectomie pour un adénocarcinome métastatique des glandes apocrines des sacs anaux. Conclusion: Les complications associées à la lymphadénectomie ilio-sacrée pour l'adénocarcinome métastatique des glandes apocrines des sacs anaux sont relativement fréquentes et concernent principalement l'hémorragie. Ces complications sont significativement associées à la taille des ganglions lymphatiques métastatiques retirés. Pertinence clinique: Cette étude rétrospective fournit des informations au clinicien concernant les complications chirurgicales potentielles pour le retrait des ganglions lymphatiques ilio-sacrés métastatiques. Ces complications, bien que rares, peuvent être graves et doivent être discutées avec les propriétaires avant la chirurgie.(Traduit par Dr Serge Messier).

Variability in tumor margin reporting for soft tissue sarcoma and cutaneous mast cell tumors in dogs: A systematic review.

OBJECTIVE: To identify which classification systems have been used for tumor margin reporting and to determine whether factors (publication year, tumor type, and specialty of the contributing authors) influenced trends in margin reporting within literature describing canine soft tissue sarcoma (STS) and cutaneous mast cell tumors (MCT). STUDY DESIGN: Systematic literature review. METHODS: Eligible articles were identified through electronic database searches performed for STS and MCT. Data abstracted from relevant studies included publication year, author list, specialty of contributing authors, criteria used to report the planned surgical margins, and the status of histologic margins. Categorization of papers was based on the classification systems used to report surgical and histologic tumor margins. RESULTS: Fifty-three articles were included, 11 on STS, 37 on MCT, and five that included both tumor types. Criteria for classifying the planned surgical margins were described in only 50.9% of studies. Articles that listed a veterinary surgeon as a contributing author (P = .01) and STS articles compared to MCT papers (P = .01) were more likely to report surgical margins. Most (56.6%) studies reported the status of histologic margins dichotomously as "complete" or "incomplete." Although a previously published consensus statement recommended that quantitative criteria be used to report histologic margins, only 7.5% of articles used quantitative methods. CONCLUSION: Classification systems used for reporting tumor margins were highly variable among studies. CLINICAL SIGNIFICANCE: The findings of this review provide evidence that a standardized classification system for reporting surgical and histologic tumor margins is required in veterinary medicine. A universal system may support more consistent reporting of neoplastic biopsy specimens and allow for more meaningful comparisons across research studies.

Influence of normograde versus retrograde catheterization of bile ducts in dogs treated for gallbladder mucocele.

OBJECTIVE: To determine the influence of normograde (NG) versus retrograde (RG) catheterization of the cystic duct and common bile duct (CBD) in dogs with gallbladder mucoceles (GBM) treated with open cholecystectomy. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n = 117) with GBM. METHODS: Medical records were reviewed for signalment, history, clinical laboratory and diagnostic imaging findings, details of surgery including catheterization method, complications, and outcome. Long-term follow-up data were obtained by telephone or electronic communication. Relationships between catheterization method and clinical variables and outcome were evaluated. RESULTS: Dogs catheterized RG were more likely to experience any postoperative complication (p = .0004) including persistence of gastrointestinal signs (p = .0003). Survival to discharge and long-term survival did not differ by group (p = .23 and p = .49). Total bilirubin (TB) decreased by 70.3% after NG catheterization compared to 39.1% after RG catheterization (p = .03) and increased in 14.9% dogs catheterized NG and 38.0% dogs catheterized RG (p = .004). The presence of a diplomate surgeon at surgery resulted in decreased incidences of any perioperative or postoperative complication (p = .003 and p = .05). CONCLUSION: Retrograde catheterization was associated with more postoperative concerns than NG catheterization, but similar survival times. Surgery should be performed by diplomates experienced in biliary surgery to minimize complications. CLINICAL SIGNIFICANCE: Although both NG and RG techniques to catheterize the cystic duct and CBD are options for treatment of GBM with low mortality, results of this study provide some evidence to recommend NG over RG catheterization.

Diagnostic accuracy of optical coherence tomography for assessing surgical margins of canine soft tissue sarcomas in observers of different specialties.

OBJECTIVE: To determine the diagnostic accuracy of optical coherence tomography (OCT) to assess surgical margins of canine soft tissue sarcoma (STS) and determine the influence of observer specialty and training. STUDY DESIGN: Blinded clinical prospective study. ANIMALS: Twenty-five dogs undergoing surgical excision of STS. METHODS: In vivo and ex vivo surgical margins were imaged with OCT after tumor resection. Representative images and videos were used to generate a training presentation and data sets. These were completed by 16 observers of four specialties (surgery, radiology, pathology, and OCT researchers). Images and videos from data sets were classified as cancerous or noncancerous. RESULTS: The overall sensitivity and specificity were 88.2% and 92.8%, respectively, for in vivo tissues and 82.5% and 93.3%, respectively, for ex vivo specimens. The overall accurate classification for all specimens was 91.4% in vivo and 89.5% ex vivo. There was no difference in accuracy of interpretation of OCT imaging by observers of different specialties or experience levels. CONCLUSION: Use of OCT to accurately assess surgical margins after STS excision was associated with a high sensitivity and specificity among various specialties. Personnel of all specialties and experience levels could effectively be trained to interpret OCT imaging. CLINICAL SIGNIFICANCE: Optical coherence tomography can be used by personnel of different specialty experience levels and from various specialties to accurately identify canine STS in vivo and ex vivo after a short training session. These encouraging results provide evidence to justify further research to assess the ability of OCT to provide real-time assessments of surgical margins and its applicability to other neoplasms.

Invasive Tendon Sheath Fibrosarcoma Causing Radial Osteolysis in a Golden Retriever.

This case report details a previously undescribed malignancy of the tendon sheath in a golden retriever. This dog originally presented with lameness of the left forelimb, at which point radiographs revealed a monostotic, lytic lesion of the distal radius with overlying soft-tissue swelling. A fine-needle aspirate was performed, and cytology was compatible with a sarcoma, with the primary differential being an osteosarcoma. After amputation, the leg was submitted for histopathology, which revealed inconsistencies with a typical osteosarcoma lesion, including lack of osteoid deposition. Second opinion histopathology showed a fibrosarcoma that appeared to have originated in the tendon sheath of an extensor tendon and then secondarily invaded the radius. At the time of publication, ∼17 mo after amputation, the dog continues to do well without any evidence of recurrent or metastatic disease.

Computed tomographic characteristics of cavitary pulmonary adenocarcinoma in 3 dogs and 2 cats.

Cavitary pulmonary lesions can result from the localized breakdown of pulmonary parenchyma or be caused by the expulsion of a necrotic part of a mass. The objectives of this study were to describe the clinical and computed tomographic characteristics for cases of cavitary pulmonary adenocarcinoma and find associations between the features and those identified in human pulmonary cavitary soft tissue lesions. Five cases were identified that had a cavitary pulmonary mass on thoracic computed tomography (CT) and histopathology of the lesions. Three dogs and 2 cats had cavitary pulmonary adenocarcinoma. Common features of CT in these cases included lesions in the caudal lung lobes, lobular and spiculated lesion margins, air bronchograms within the mass, pleural tags, heterogeneous contrast enhancement, and ground glass opacity in the surrounding parenchyma. The findings of this case series suggest there are similarities in the CT characteristics of malignancy in human and animal cavitary pulmonary masses.

Caractéristiques tomodensitométriques d'adénocarcinome pulmonaire cavitaire chez trois chiens et deux chats. Les lésions pulmonaires cavitaires peuvent résulter de la dégradation localisée du parenchyme pulmonaire ou être provoquées par l'expulsion d'une partie nécrotique d'une masse. Les objectifs de cette étude étaient de décrire les caractéristiques cliniques et tomodensitométriques de cas d'adénocarcinome pulmonaire cavitaire et de trouver des associations entre les caractéristiques et celles identifiées dans les lésions des tissus mous de la cavité pulmonaire humaine. Cinq cas ont été identifiés avec une masse pulmonaire cavitaire par tomodensitométrie (TDM) thoracique et histopathologie des lésions. Trois chiens et deux chats avaient un adénocarcinome pulmonaire cavitaire. Les caractéristiques communes de la tomodensitométrie dans ces cas comprenaient des lésions dans les lobes du poumon caudal, des marges lobulaires et spiculées des lésions, des bronchogrammes aériens dans la masse, des étiquettes pleurales, l'augmentation du contraste hétérogène et une opacité d'apparence de verre dépoli dans le parenchyme environnant. Les résultats de cette série de cas suggèrent qu'il existe des similitudes dans les caractéristiques tomodensitométriques de la malignité dans les masses pulmonaires cavitaires humaines et animales.(Traduit par Dr Serge Messier).

A systematic review of surgical margins utilized for removal of cutaneous mast cell tumors in dogs.

BACKGROUND: Traditionally, wide lateral surgical margins of 3 cm and one fascial plane deep have been recommended for resection of canine cutaneous mast cell tumor (MCT). Several studies have been published assessing surgical margins of less than this traditional recommendation. The objective of this systematic review was to determine if resection MCT with lateral surgical margins < 3 cm results in low rates of incomplete resection and local tumor recurrence. Systematic searches of digital bibliographic databases were performed with two authors (AR & LES) screening abstracts to identify relevant scientific articles. Studies regarding surgical treatment of dogs with cutaneous MCT were reviewed. Data abstraction was performed and the quality of individual studies and the strength of the body of evidence for utilization of surgical margins < 3 cm for removal of MCTs was assessed. RESULTS: From the initial 78 citations identified through the database searches, four articles were retained for data abstraction after both relevance screenings were performed. Two studies were retrospective observational studies, one was a prospective case series and one was a prospective clinical trial. Assessment of the quality level of the body of evidence identified using the GRADE system was low. Excision of MCT at 2 cm and 3 cm was associated with comparably low rates of incomplete excision and recurrence. CONCLUSIONS: Despite the low quality of the overall body of evidence, a recommendation can be made that resection of canine cutaneous MCTs (< 4 cm) of Patnaik grade I and II with 2 cm lateral margins and 1 fascial plane deep results in low rates of incomplete excision and local tumor recurrence.

Near-infrared imaging and optical coherence tomography for intraoperative visualization of tumors.

Surgical excision is the foundation of treatment for early-stage solid tumors in man and companion animals. Complete excision with appropriate margins of surrounding tumor-free tissue is crucial to survival. Intraoperative imaging allows real-time visualization of tumors, assessment of surgical margins, and, potentially, lymph nodes and satellite metastatic lesions, allowing surgeons to perform complete tumor resections while sparing surrounding vital anatomic structures. This Review will focus on the use of near-infrared imaging and optical coherence tomography for intraoperative tumor visualization.

Corrective osteotomy and partial tarsal arthrodesis in two greyhounds with calcaneal malunion.

OBJECTIVE: To describe the clinical presentation and outcome of two greyhounds with calcaneal malunions that were treated with corrective osteotomy and partial tarsal arthrodesis. STUDY DESIGN: Short case series. ANIMALS: Two adult racing greyhounds. METHODS: Varus and recurvatum deformity of the calcaneus was ascribed to malunion of prior calcaneal fracture with concomitant central bone fracture that had been sustained during racing in both dogs. Both dogs exhibited severe, weight-bearing lameness and had radiographic evidence of moderate to severe osteoarthritis of the proximal intertarsal joint. A closing wedge corrective osteotomy and partial tarsal arthrodesis were performed with a 2.7-mm locking compression plate and cancellous autograft. RESULTS: Calcaneal morphology and alignment of the common calcaneal tendon seemed restored postoperatively. The implant was removed in one dog, while the other dog experienced no postoperative complications. Lameness improved in both dogs, although residual intermittent lameness after heavy exercise was reported by owners of both dogs 1 year after surgery. Overall, owner satisfaction and outcome were considered good-to-excellent in both dogs. CONCLUSION: Corrective osteotomy and partial tarsal arthrodesis for treatment of malunited calcaneal fractures may be considered in dogs with clinical signs related to calcaneal malunion.

Evaluation of microwave ablation for local treatment of dogs with distal radial osteosarcoma: A pilot study.

OBJECTIVE: To evaluate the feasibility and safety of microwave ablation (MWA) as a modality to induce tumor necrosis within distal radial osteosarcoma (OSA). STUDY DESIGN: Pilot study. ANIMALS: Six client-owned dogs with distal radius OSA confirmed by cytological examination. METHODS: Dogs underwent computed tomography for surgical planning before general anesthesia for fluoroscopy-guided ablation. Computed tomography was repeated 48 hours after MWA, before amputation. The ablated tumor was evaluated with histopathology. RESULTS: Six dogs underwent MWA of distal radius OSA. A lower power setting (30 W) was selected for the first two dogs to avoid collateral soft tissue damage. The power was increased to 75 W for the last four dogs. The temperature was maintained between 45°C and 55°C (113 °F-131 °F) at the bone/soft tissue interface. Tumor necrosis varied between 30% and 90% (median, 55%) according to histopathology. No intraoperative or periprocedural complications were observed. CONCLUSION: Microwave ablation induced variable tumor necrosis and did not induce immediate postablation complications in these six dogs with distal radius OSA. CLINICAL SIGNIFICANCE: These results justify further evaluation of MWA as a potential modality to treat primary bone lesions in dogs.

Outcomes of 43 small breed dogs treated for splenic hemangiosarcoma.

OBJECTIVE: To determine outcome and prognostic factors in small breed dogs in which hemangiosarcoma was diagnosed and whether outcomes differed between small and large breed dogs with splenic hemangiosarcoma. STUDY DESIGN: Bi-institutional retrospective study. ANIMALS: Forty-three small breed (<20 kg) and 94 large breed client-owned dogs. METHODS: Medical records were reviewed to identify dogs treated with splenectomy for splenic hemangiosarcoma. Data acquired included signalment, preoperative staging, bloodwork results, surgical findings, histopathologic findings, administration of chemotherapy, presence/absence of metastatic disease, and survival time (ST). Cox proportional hazards regression analysis was performed to assess prognostic factors associated with survival. RESULTS: The overall median ST was 116 days and 97 days for small and large breed dogs, respectively. The ST for dogs treated with surgery and chemotherapy was 207 and 139 days for small and large breed dogs, respectively. The disease-free interval (DFI) was 446 and 80 days for small and large breed dogs, respectively. Dog size was associated with DFI (P = .02) but not with ST (P = .09). The presence of metastasis at diagnosis was associated with decreased ST in small (P = .03) and large (P = .0009) breed dogs. Administration of chemotherapy (P = .02) was associated with increased ST (P = .02) in small breed dogs. CONCLUSION: The ST was not different in small and large breed dogs with splenic hemangiosarcoma treated with splenectomy and chemotherapy. CLINICAL SIGNIFICANCE: Prognosis remains poor despite aggressive therapies in small and large breed dogs.

Percutaneous microwave ablation of solitary presumptive pulmonary metastases in two dogs with appendicular osteosarcoma.

OBJECTIVE: To describe percutaneous microwave ablation (MWA) of presumptive pulmonary metastases and the outcome of two dogs. ANIMALS: Two dogs with pulmonary lesions after treatment of spontaneously occurring appendicular osteosarcoma. STUDY DESIGN: Preliminary prospective clinical study. METHODS: Two large-breed dogs were referred from tertiary veterinary hospitals 146 and 217 days after limb amputation to pursue MWA as an alternative therapy to metastasectomy. Both dogs had been receiving chemotherapy protocols at their respective referral centers. RESULTS: A novel percutaneous approach for MWA with ultrasonographic or computed tomographic (CT) guidance was successfully performed. The only complications consisted of pneumothoraxes, requiring treatment in one dog. In the weeks after their procedures, both dogs were reported to do well at home. Dog 1 died and dog 2 was euthanized 82 and 19 days, respectively, after their MWA of confirmed (dog 1) or presumed (dog 2) metastatic disease. CONCLUSION: Percutaneous MWA of pulmonary nodules was technically feasible in two dogs without major complications. CLINICAL SIGNIFICANCE: Percutaneous MWA may provide a minimally invasive option for treatment of osteosarcoma pulmonary metastases. Additional studies are required to evaluate the benefits of MWA on survival and confirm histologic cell death within pulmonary neoplastic lesions.

Pharmacokinetics of platinum and safety evaluation of carboplatin-impregnated calcium sulfate hemihydrate beads after implantation in healthy cats.

OBJECTIVE: To evaluate the pharmacokinetics (PK) of platinum (Pt) and safety of carboplatin-impregnated calcium sulfate hemihydrate (C-I CSH) beads after implantation in healthy cats. STUDY DESIGN: In vivo experimental study. ANIMALS: Six healthy adult cats. METHODS: Three C-I CSH beads were implanted in muscle pockets over the right and left hemithoraces of each cat (~3.9 mg/kg of Pt; 60.4 mg/m2 of calculated carboplatin). Hematology and blood chemistry were tested at baseline and 3, 7, 14, and 21 days postimplantation. Serum was analyzed for Pt at specific times from 1 hour to 21 days. Tissue was obtained for histopathology and analysis of Pt at 3, 7, 14, and 21 days at standardized distances from implantation sites. RESULTS: Platinum was detected in tissues at all times and distances (range, 0.1-4.19 µg/g). Serum Pt increased up to 2.6 hours (3.25 µg/mL) then decreased sharply. Samples containing muscle had higher Pt compared with samples without muscle (P = .004). Mild hypercalcemia was noted in four cats, and mild inflammatory reaction was noted on histopathology of all samples. CONCLUSION: Platinum was released from C-I CSH beads differentially into surrounding tissues over 21 days. Systemic absorption of Pt was minimal, but mild hypercalcemia occurred. CLINICAL SIGNIFICANCE: Implantation was well tolerated by healthy adult cats. Securing beads within muscle may limit Pt diffusion to targeted tissue. Although Pt concentrations did not achieve levels reported to be cytotoxic for feline sarcoma cells in culture, results provide evidence to support evaluation of efficacy in the tumor microenvironment of cats with locally invasive cancers.

Outcomes associated with vaginectomy and vulvovaginectomy in 21 dogs.

OBJECTIVE: To report the outcomes of dogs with lesions of the genitourinary tract treated by vaginectomy or vulvovaginectomy. STUDY DESIGN: Multi-institutional retrospective study. ANIMALS: Female dogs that underwent vulvovaginectomy, complete vaginectomy, or subtotal vaginectomy from 2003 to 2018 with complete medical records and a minimum of 60 days follow-up. METHODS: Data collected from medical records included preoperative, intraoperative, and postoperative data, such as the occurrence of urinary incontinence (UIC), disease recurrence, and death/euthanasia. RESULTS: This study included 21 dogs. Four dogs had vulvovaginectomy, six had complete vaginectomy, and 11 had a subtotal vaginectomy performed. The mean age at surgery was 9.2 years (SD, 3.3). Thirteen dogs were intact at presentation. Smooth muscle tumors were diagnosed most commonly (10 leiomyomata, three leiomyosarcomas, two leiomyofibromas). The median duration of follow-up was 520 days (range, 71-1955). Major complications requiring revision surgery were recorded in two dogs. Postoperative UIC occurred in six of 21 dogs, resolving spontaneously within 60 days in three dogs. Dogs with malignant tumors (n = 6) survived at least 71 days (median, 626; 95% CI, 71-1245), and recurrence of disease occurred in two dogs. In dogs with benign tumors (n = 15), the median survival time was not reached. These dogs survived at least 104 days and had no recurrence of the disease. CONCLUSION: Vaginectomy and vulvovaginectomy resulted in prolonged survival and low rates of major complications and UIC. CLINICAL SIGNIFICANCE: This study provides evidence to recommend that the risks of this procedure and expectations should be discussed with clients.

Prognostic factors for short-term survival of dogs that experience postattenuation seizures after surgical correction of single congenital extrahepatic portosystemic shunts: 93 cases (2005-2018).

OBJECTIVE: To identify prognostic factors for short-term survival of dogs that experience seizures within 7 days after surgical correction of single congenital extrahepatic portosystemic shunts (cEHPSS). STUDY DESIGN: Multi-institutional retrospective study. SAMPLE POPULATION: Ninety-three client-owned dogs. METHODS: Medical records at 14 veterinary institutions were reviewed to identify dogs that underwent surgical attenuation of a single cEHPSS from January 1, 2005 through February 28, 2018 and experienced postattenuation seizures (PAS) within 7 days postoperatively. Logistic regression analysis was performed to identify factors associated with 1-month survival. Factors investigated included participating institution, signalment, shunt morphology, concurrent/historical conditions, presence of preoperative neurologic signs, presence of preoperative seizures, aspects of preoperative medical management, surgical details including method and degree of shunt attenuation, type of PAS (focal only or generalized ± focal), drugs administered as part of the treatment of PAS, and development of complications during treatment of PAS. RESULTS: Thirty (32.3%) dogs survived to 30 days. Seventy-six (81.7%) dogs experienced generalized PAS. Factors positively associated with short-term survival included having a history of preoperative seizures (P = .004) and development of focal PAS only (P = .0003). Most nonsurvivors were humanely euthanized because of uncontrolled or recurrent seizures. CONCLUSION: Dogs that experienced PAS that had a history of preoperative seizures and those that experienced focal PAS only had significantly improved short-term survival. CLINICAL SIGNIFICANCE: The results of this study provide information that will help in the counseling of owners who seek treatment for PAS after surgical correction of cEHPSS. © 2020 The American College of Veterinary Surgeons.