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Multilobular osteochondrosarcoma (MLO) of the os penis was diagnosed in a dysuric dog. Recurrence was confirmed or suspected twice over a 22-month period. This is the first reported case of MLO occurring in the os penis, and the 5th reported case of neoplasia of the os penis in the dog.

Objective: To compare short- and long-term outcome and complications of chest wall reconstruction in dogs using autogenous, prosthetic, and composite autogenous-prosthetic techniques., Study Design: Historical cohort., Animals: Dogs (n=44) with spontaneous tumors arising from or involving the chest wall., Methods: Medical records were reviewed for dogs with rib and/or sternal tumors treated by chest wall resection and reconstruction. Signalment, preoperative clinical features, intraoperative findings and complications, reconstruction technique (autogenous muscle flap, prosthetic mesh, or composite autogenous-prosthetic technique), and short- (< or =14 days) and long-term (>14 days) postoperative complications were determined from the medical records and telephone contact with owners and referring veterinarians. Associations between chest wall reconstruction technique and postoperative complications were tested with Cox proportional hazards., Results: Chest wall defects were reconstructed with autogenous muscle flaps (29 dogs), prosthetic mesh (3), and a composite technique of prosthetic mesh and either autogenous muscle or omental pedicle flap (12). Early postoperative complications were recorded in 8 dogs (18.2%) and included seroma (5) and pleural effusion and peripheral edema (3). One dog had a late complication (2.3%) with a mesh-related infection 767 days postoperatively. Overall, complications occurred in 10.3% of autogenous, 25.0% of composite, and 66.7% of prosthetic reconstructions. Chest wall reconstruction with Marlex mesh alone was associated with a significantly increased risk of postoperative complications compared with autogenous reconstruction (P=.027). Reconstruction of sternal defects (3), 2 of which were performed with Marlex mesh alone, was associated with a significantly increased risk of complications compared with lateral chest wall reconstructions (P=.037)., Conclusions: Large chest wall defects can be reconstructed with autogenous and composite techniques, but prosthetic mesh should be covered with well-vascularized autogenous muscle or omentum to decrease the risk of postoperative complications. Sternal defects should be reconstructed with rigid techniques., Clinical Relevance: Chest wall reconstruction with autogenous muscle flaps or a combination of autogenous techniques with prosthetic mesh is associated with a low rate of infection and other complications.

Objective: To describe the clinical features and determine oncologic outcome and prognostic factors for dogs with primary tumors of the osseous chest wall., Study Design: Historical cohort., Animals: Dogs (n=39) with spontaneous tumors involving the chest wall., Methods: Medical records were reviewed for dogs with rib and/or sternal tumors treated by chest wall resection and reconstruction. Signalment, preoperative clinical features, reconstruction technique, and oncologic outcome (local tumor recurrence, metastasis, and survival time) were determined from medical records and by telephone contact with owners and referring veterinarians. Oncologic outcome and prognostic factors were determined using Kaplan-Meier survival analysis and Cox proportional hazards. Logistic regression was used to determine if increased serum alkaline phosphatase (ALP) concentration was associated with tumor type., Results: Of the 39 dogs with tumors arising from the chest wall, 25 had osteosarcoma, 12 had chondrosarcoma, and 2 dogs had hemangiosarcoma. Median survival time (MST) for dogs with rib osteosarcoma was 290 days. Increased activity of total ALP significantly decreased survival in dogs with osteosarcoma (210 days versus 675 days, P=.0035). MST for dogs with rib chondrosarcoma was not reached (mean 1301 days) and survival was significantly greater than all other types of rib tumors (P=.0321)., Conclusion: Rib tumors should be resected with wide margins to decrease the risk of incomplete excision, because local tumor recurrence has a significant impact on the survival time. The prognosis for dogs with rib chondrosarcoma is very good, but guarded for other types of tumors., Clinical Relevance: Osteosarcoma and chondrosarcoma are the most common primary tumors of the chest wall. Prognosis for dogs with primary rib chondrosarcoma is very good with surgery alone, but surgery and adjunctive chemotherapy is recommended for dogs with primary rib osteosarcoma and the prognosis remains guarded.

Canine histiocytic diseases are an emerging spectrum of diseases characterized by proliferations of histiocytic cells. Nonneoplastic histiocytic disease (reactive histiocytosis, comprising cutaneous and systemic histiocytosis) is uncommon. Neoplastic histiocytic diseases include cutaneous histiocytoma, which is a benign histiocytic tumor, and localized and disseminated histiocytic sarcoma (previously known as malignant histiocytosis), which are malignant diseases. The differentiation of histiocytic diseases can be challenging. This article outlines the characteristics of each disease entity and details the clinicopathologic, histologic, immunohistochemical, prognostic, and therapeutic differences among them.

A 6-year-old, male castrated domestic shorthair cat was presented for evaluation of lethargy, vomiting, anorexia, and constipation. Physical examination revealed an elevated body temperature and an extramural colonic mass. Abdominal ultrasonography demonstrated a hypoechoic mass measuring 2.2 cm in maximum dimension immediately caudal to the bladder. Cytological evaluation of a fine-needle aspirate confirmed the mass was a prostatic abscess. Abdominal celiotomy and prostatic omentalization were successful in resolving clinical abnormalities. Feline prostatic abscessation is a rare condition that has not been previously reported and may have a good outcome if treated early and appropriately.

Nine dogs were diagnosed with cranial mediastinal carcinomas. Based on histological and immunohistochemical analysis, four dogs were diagnosed with ectopic follicular cell thyroid carcinomas, one dog with ectopic medullary cell thyroid carcinoma, two dogs with neuroendocrine carcinomas and two dogs with anaplastic carcinomas. Clinical signs and physical examination findings were associated with a space-occupying mass, although one dog was diagnosed with functional hyperthyroidism. Surgical resection was attempted in eight dogs. The cranial mediastinal mass was invasive either into the heart or into the cranial vena cava in three dogs. Resection was complete in six dogs and unresectable in two dogs. All dogs survived surgery, but four dogs developed pulmonary thromboembolism and two dogs died of respiratory complications postoperatively. Adjunctive therapies included pre-operative radiation therapy (n=1) and postoperative chemotherapy (n=3). Three dogs had metastasis at the time of diagnosis, but none developed metastasis following surgery. The overall median survival time was 243 days. Local invasion, pleural effusion and metastasis did not have a negative impact on survival time in this small case series.

The biomechanical characteristics of 1.2 mm diameter allogeneic cortical bone pins harvested from the canine tibia were evaluated and compared to 1.1 mm diameter stainless steel pins and 1.3 mm diameter polydioxanone (PDS) pins using impact testing and four-point bending. The biomechanical performance of allogeneic cortical bone pins using impact testing was uniform with no significant differences between sites, side, and gender. In four-point bending, cortical bone pins harvested from the left tibia (204.8 +/- 77.4 N/mm) were significantly stiffer than the right tibia (123.7 +/- 54.4 N/mm, P = 0.0001). The site of bone pin harvest also had a significant effect on stiffness, but this was dependent on interactions with gender and side. Site C in male dogs had the highest mean stiffness in the left tibia (224.4 +/- 40.4 N/mm), but lowest stiffness in the right tibia (84.9 +/- 24.2 N/mm). Site A in female dogs had the highest mean stiffness in the left tibia (344.9 +/- 117.4 N/mm), but lowest stiffness in the right tibia (60.8 +/- 3.7 N/mm). The raw and adjusted bending properties of 1.2 mm cortical bone pins were significantly better than 1.3 mm PDS pins, but significantly worse than 1.1 mm stainless steel pins (P < 0.0001). In conclusion, cortical bone pins may be suitable as an implant for fracture fixation based on initial biomechanical comparison to stainless steel and PDS pins used in clinical practice.

Objective: To determine the efficacy and toxic effects of epirubicin for the adjuvant treatment of dogs with splenic hemangiosarcoma and identify prognostic factors., Design: Retrospective case series., Animals: 59 client-owned dogs that underwent splenectomy for splenic hemangiosarcoma treated with or without epirubicin., Procedures: Medical records were examined for signalment, clinical signs, diagnostic and surgical findings, and postoperative outcome. For dogs treated with epirubicin, dose numbers, intervals, and reductions and type and severity of toxic effects were recorded. Dogs were allotted to 2 groups: splenectomy alone and splenectomy with adjuvant epirubicin treatment., Results: 18 dogs received epirubicin (30 mg/m(2)) every 3 weeks for up to 4 to 6 treatments. Forty-one dogs were treated with splenectomy alone. The overall median survival time was significantly longer in dogs treated with splenectomy and epirubicin (144 days), compared with splenectomy alone (86 days). Median survival time for dogs with stage I disease (345 days) was significantly longer than for dogs with either stage II (93 days) or III disease (68 days). Seven of 18 dogs treated with epirubicin were hospitalized for signs of adverse gastrointestinal effects. Inappetence, long duration of clinical signs, thrombocytopenia, neutrophilia, and high mitotic rate were negative prognostic factors., Conclusions and Clinical Relevance: Epirubicin may be as efficacious as adjuvant doxorubicin-based protocols, but may result in a higher incidence of adverse gastrointestinal effects. Epirubicin should be considered as an alternative to doxorubicin in dogs with preexisting cardiac disease, as clinical epirubicin cardiotoxicity was not diagnosed in treated dogs.

Malignant thyroid carcinomas are relatively common in dogs. The majority of tumors are unilateral and nonfunctional. Before deciding on treatment options, it is important to determine whether the tumor is freely moveable or fixed and invasive into adjacent tissues. Thyroidectomy is recommended for unilateral, mobile thyroid carcinomas. Radiation therapy or radioactive iodine therapy are recommended for dogs with invasive or bilateral thyroid carcinomas. The role of adjunctive chemotherapy is poorly defined, but should be considered in dogs with high-risk tumors, such as large or bilateral thyroid carcinomas. The prognosis is good following surgical treatment of mobile thyroid tumors and irradiation of fixed thyroid carcinomas, with median survival times greater than 3 years.

Pins constructed from cortical bone may provide a reasonable alternative to other fracture-fixation devices by circumventing some of the complications associated with stainless steel and synthetic biodegradable implants. However, it is unknown whether cortical bone pins provide comparable strength compared to conventional pins. Using four-point bending, we compared the mechanical characteristics of 1.2-mm allogeneic cortical bone pins milled from specific regions of human tibiae and femora to commercially available 1.1-mm diameter stainless steel pins and 1.3-mm diameter polydioxanone pins. We used impact testing to identify mechanical differences in cortical bone pins between gender and harvest site. Cortical bone pins had better mechanical properties in four-point bending compared with polydioxanone pins, but not stainless steel pins. Pins milled from the right tibiae of males had the best bending characteristics. The mechanical performance of 1.2-mm cortical bone pins was comparable to those of stainless steel and polydioxanone pins regardless of site, bone, and gender. The clinical investigation of cortical bone pins as an implant for fracture fixation is warranted based on mechanical testing and comparison to commercially available polydioxanone and stainless steel pins.

Background: Primary renal tumors are diagnosed uncommonly in dogs., Hypothesis: Signs and survival will differ among different categories of primary renal tumors., Animals: Data were collected from the medical records of 82 dogs with primary renal tumors diagnosed by examination of tissue obtained by ultrasound-guided biopsy, needle aspiration, surgery, or at postmortem examination., Methods: This was a multi-institutional, retrospective study., Results: Forty-nine dogs had carcinomas, 28 had sarcomas, and 5 had nephroblastomas. The dogs were geriatric (mean 8.1 years; range: 1-17) with a weight of 24.9 kg (range: 4.5-80). Tumors occurred with equal frequency in each kidney with 4% occurring bilaterally. Initial signs included one or more of hematuria, inappetance, lethargy. weight loss, or a palpable abdominal mass. Pain was reported more frequently in dogs with sarcomas (5/28). The most common hematologic abnormalities were neutrophilia (22/63), anemia (21/64), and thrombocytopenia (6/68). Polycythemia was present in 3 dogs and resolved with treatment. Hematuria (28/49), pyuria (26/49), proteinuria (24/50), and isosthenuria (20/56) were the most frequently observed abnormalities on urinalysis. Pulmonary metastases were noted on thoracic radiographs in 16% of dogs at diagnosis. Seventy-seven percent of dogs had metastatic disease at the time of death. Median survival for dogs with carcinomas was 16 months (range 0-59 months), for dogs with sarcomas 9 months (range 0-70 months), and for dogs with nephroblastomas 6 months (range 0-6 months)., Conclusions and Clinical Importance: Primary renal tumors in dogs are generally highly malignant with surgery being the only treatment that improves survival.

Objective: To compare surgical and oncologic outcome in dogs with osteosarcoma (OSA) of the distal aspect of the radius treated with limb-sparing surgery, using either a cortical allograft or endoprosthesis, and postoperative chemotherapy; and to evaluate predictive factors for outcome., Study Design: Prospective cohort study., Animals: Dogs (n = 20) with spontaneous, non-metastatic OSA of the distal aspect of the radius., Methods: Dogs were prospectively randomized for limb-sparing surgery with either a cortical allograft (n = 10) or endoprosthesis (10) and full-course adjuvant chemotherapy using single or dual agent protocols of cisplatin, carboplatin, and/or doxorubicin. Surgical (intraoperative findings, postoperative infection, construct failure) and oncologic (local tumor recurrence, metastasis, survival) outcomes were compared. The influence of intraoperative and postoperative variables on surgical and oncologic outcome were evaluated., Results: No clinically significant differences in surgical and oncologic outcome were detected between groups. The percentage of radius replaced by the implant was significantly greater in the endoprosthesis group (60.9% compared with 48.6%, P = .008). Median survival time (MST) for dogs with construct failure, regardless of implant type, was 685 days and significantly greater than MST of dogs without construct failure (322 days, P = .042; hazard ratio [HR] 16.82). Median metastasis-free interval and MST (685 days versus 289 days; P = .034, HR 24.58) were significantly greater in dogs with postoperative infection. Disease-free and overall limb-salvage rates were 70% and 85%, respectively. Overall MST was 430 days., Conclusions: For dogs with OSA of the distal aspect of the radius, a cortical allograft or endoprosthesis can be used for limb-sparing surgery. Construct failure and postoperative infection significantly improve survival time regardless of implant type., Clinical Relevance: An endoprosthesis is an attractive alternative to cortical allografts for limb-salvage of the distal aspect of the radius in dogs because surgical and oncologic outcomes are similar, but the endoprosthesis is an immediately available off-the-shelf implant which is not complicated by the bone harvesting and banking requirements associated with cortical allografts. Mechanisms whereby postoperative infection improves survival time requires further investigation and, if elucidated, may provide the opportunity to improve the outcome of dogs and humans with OSA.

Case Description: A 2-year-old Siberian Husky was evaluated because of a 2-week history of coughing and gagging and decreased appetite and activity level., Clinical Findings: Radiography, surgery, and immunohistochemical examination revealed a solitary sclerosing mesothelioma extending from the left thoracic diaphragmatic surface that was adherent to the pericardium and the caudal mediastinum., Treatment and Outcome: The tumor was resected along with most of the left hemidiaphragm, and the left transversus abdominis muscle was used to reconstruct the diaphragm. The 13th rib formed the base of the muscle flap. The muscle flap was transposed into the defect so that the mesothelium-lined surface faced the thoracic cavity and the deep aspect of the muscle formed the abdominal surface of the diaphragm. To minimize risk of adhesions, the exposed raw aspect of the abdominal surface was covered with porcine small intestinal submucosa. Recovery was uncomplicated, and the dog's appetite and activity level soon returned to normal. Evaluation 54 days after surgery revealed 2 subcutaneous masses on the thorax and masses in the liver and both kidneys; histologic and immunohistochemical analyses revealed metastasis of the original tumor. The dog was euthanatized., Clinical Relevance: Hemidiaphragmatic reconstruction with a transversus abdominis muscle flap after resection of a diaphragmatic tumor was successful. The muscle flap was easily harvested and transposed into the diaphragmatic defect.

Objective: To compare the biomechanical properties of cortical bone and surgical steel endoprosthesis for limb-sparing surgery of the distal radius in dogs and evaluate the role of the ulna in providing stability to the reconstructed limb., Study Design: Cadaveric biomechanical study., Animals: Twelve pairs of normal canine thoracic limbs., Methods: Paired limbs were divided into 4 groups: endoprosthesis and cortical bone graft, with and without preservation of the ulna. In each limb pair, the distal segment of the radius resected from the limb to be reconstructed with an endoprosthesis was used as the cortical bone graft in the contralateral limb. The ulna was resected en bloc with the radius and at the same level as the radial osteotomy in limbs where the ulna was not preserved. Limbs were tested in axial loading until failure. The load-deformation curve was used to acquire the biomechanical properties of each construct, which were compared using 2-way ANOVA. Failure modes were compared descriptively., Results: Limbs reconstructed with the endoprosthesis had significantly greater yield load, energy at yield, and ultimate load compared with limbs reconstructed with a cortical bone graft. There were no significant differences in either energy to failure or stiffness between the 2 constructs. Preservation of the ulna did not significantly improve any of the biomechanical properties tested with either endoprosthesis or cortical bone graft constructs. The modes of failure in all 4 groups were variable and inconsistent., Conclusions: Limbs reconstructed with an endoprosthesis were biomechanically superior to limbs reconstructed with a cortical bone graft in axial loading to failure. Preservation of the ulna is not required to improve the stability in axial compression after limb-sparing surgery of the distal radius., Clinical Relevance: The endoprosthesis may provide another option for limb-sparing surgery of the distal radius in dogs. It has potential advantages when compared with cortical bone grafts, including better biomechanical performance and resistance to implant failure in axial compression, immediate availability, and no requirement for bone banking facilities. The ulna can be resected en bloc with the radius without having a negative impact on construct stability. En bloc resection of the ulna and radius may decrease the risk of local tumor recurrence after limb-sparing surgery.

Objective: To report successful limb-sparing surgery in a dog with a proximal femoral osteosarcoma (OSA) using a composite allograft-prosthetic technique., Study Design: Case report., Animal: Client-owned dog., Methods: A stage IIB OSA of the proximal aspect of the femur was resected in accordance with oncologic and limb-sparing principles. The osseous defect was reconstructed with a proximal femoral allograft and cemented, long-stemmed femoral prosthesis. Soft tissue reconstruction was achieved by suturing host tendons to their respective allogeneic tendons on the allograft. Coxofemoral joint function was preserved using standard total hip arthroplasty techniques., Results: Limb-sparing surgery of the proximal aspect of the femur using a composite allograft-prosthetic technique resulted in excellent limb function. Postoperative complications included aseptic loosening of the femoral composite graft and allograft nonunion, which required revision, traumatic implant luxation, and local tumor recurrence. Limb function was excellent after surgical stabilization of the allograft nonunion but deteriorated after implant luxation 270 days postlimb-sparing surgery. Pulmonary and skeletal metastases were diagnosed and local tumor recurrence suspected 596 and 650 days postoperatively, respectively. The dog was euthanatized 688 days after limb-sparing surgery as a result of progressive local and metastatic disease., Conclusions and Clinical Relevance: Limb-sparing surgery for dogs with primary bone tumors of the proximal aspect of the femur is feasible with good functional results.

Eleven dogs with malignant tumors of the digits and feet were treated with partial foot amputation. Partial foot amputation involved amputation of one or both central weight-bearing digits. Lameness occurred in all dogs but resolved in eight dogs at a median of 37 days postoperatively. In the remaining three dogs, lameness improved but did not resolve. Tumor control was excellent, with no evidence of local recurrence in 10 dogs. One dog underwent limb amputation. Based on these results, partial foot amputation may be recommended in the management of malignant tumors of the canine foot in which more than one digit must be amputated to achieve adequate surgical margins.

Twelve dogs were diagnosed with osteosarcoma of the proximal radius or distal humerus from 1990 to 2002, representing 1.0% of all dogs diagnosed with appendicular osteosarcoma. The median body weight (29.8 kg) was significantly less than that of dogs with appendicular osteosarcoma at other sites. Ten dogs were treated with amputation and chemotherapy. These dogs had a metastatic rate of 60%, a median metastasis-free interval of 356 days, and a median survival time of 824 days. There were no significant differences in metastasis-free interval or survival time between dogs with osteosarcoma of the proximal radius or distal humerus and dogs with appendicular osteosarcoma at other sites.

Objective: To determine clinical signs, diagnostic findings, outcome, and prognostic factors in dogs treated surgically for massive hepatocellular carcinoma (HCC) and compare survival times of surgically and conservatively treated dogs., Design: Retrospective study., Animals: 48 dogs., Procedure: Medical records were examined for clinical signs, diagnostic and surgical findings, and postoperative outcome. Dogs were allocated into surgery and nonsurgery groups depending on whether curative-intent liver lobectomy was performed. Data from the surgical and nonsurgical groups were analyzed to identify prognostic factors and determine and compare rates of tumor control and survival time., Results: 42 dogs were treated surgically, and 6 were managed conservatively. In the surgery group, intraoperative mortality rate was 4.8% with no local recurrence, metastatic rate was 4.8%, and median survival time was > 1,460 days (range, 1 to 1,460 days). High alanine aminotransferase and aspartate aminotransferase activities were associated with poor prognosis. Median survival time for the nonsurgery group was 270 days (range, 0 to 415 days), which was significantly less than that of surgically treated dogs., Conclusions and Clinical Relevance: Liver lobectomy is recommended for dogs with massive HCC because tumor-related mortality rate was 15.4 times higher in dogs in the nonsurgery group, compared with the surgery group. Tumor control was excellent after surgical resection with no local recurrence and a low metastatic rate. Prognostic factors were identified, but their clinical relevance was uncertain because only 9.5% of dogs in the surgery group died as a result of their disease.

Pneumonectomy is the resection of all lung lobes in either the left or right lung field. The surgical technique and postoperative results of pneumonectomy for clinical disease have not been reported in companion animals. Pneumonectomy was performed in three dogs and one cat to treat pulmonary or pleural disease, and the postoperative outcome compared with the complications and results reported in the human literature. One dog died immediately postoperatively due to suspected respiratory insufficiency and the remaining three animals survived the perioperative period. Postoperative complications were reported in two animals. Cardiac complications occurred in the cat, with perioperative arrhythmias and progressive congestive heart failure. Gastrointestinal complications were diagnosed in one dog, with mediastinal shift and oesophageal dysfunction. Left- and right-sided pneumonectomy is feasible in companion animals, and the postoperative outcome and complications encountered in this series were similar to those reported in humans.

Objective: To assess cystoscopic transurethral resection (TUR) for the palliative management of dogs with neoplastic infiltration of the urethra., Study Design: Prospective clinical trial., Animals: Six client-owned dogs., Methods: Cystoscopic examination and electrosurgical TUR were performed in dogs with urination difficulties caused by prostatic or urethral neoplasia. TUR was performed in a retrograde manner in female dogs and antegrade in male dogs via exploratory celiotomy and ventral cystotomy. Cystoscopic examination was used to determine the extent of neoplastic involvement of the urethra. TUR involved piecemeal removal of neoplastic tissue from the urethral lumen using an electrocautery cutting loop. Hemorrhage was controlled with a cystoscopic cauterized roller-ball. In 2 male dogs, intraoperative radiation therapy (IORT) was used to treat both prostatic neoplasia and the sublumbar lymph node bed. Surgical technique, complications, adjuvant treatment, and outcome were recorded., Results: TUR was performed in 3 male dogs with prostatic carcinoma and 2 female dogs with urethral transitional cell carcinoma (TCC). In 1 female dog, TUR was attempted but not successful because of cystoscope diameter. Iatrogenic urethral perforation occurred during TUR in 3 dogs. In 2 dogs, prolonged exposure to lavage fluid resulted in clinical and biochemical abnormalities consistent with TUR syndrome. Dysuria resolved in 5 dogs within 10 days of TUR. Treatment-related complications included urinary tract infection and tumor seeding. Local tumor progression and metastasis occurred in all dogs., Conclusions: TUR (in combination with chemotherapy+/-IORT) resulted in rapid palliation of urination difficulties in male dogs with prostatic carcinoma. In female dogs with urethral TCC, however, electrosurgical TUR cannot be recommended because of a high intra- and postoperative complication rate with no improvement in postoperative management compared with historical reports of tube cystostomy., Clinical Relevance: TUR is a novel alternative for the palliation of male dogs with prostatic carcinoma. In female dogs with urethral TCC, electrosurgical TUR does not provide any advantages compared with tube cystostomy.

Synovial cell sarcoma (SCS) with metastasis to the regional lymph node was diagnosed in two cats. Synovial cell sarcomas are rare in cats and metastatic SCS has not previously been reported. In both cases, treatment consisted of limb amputation and adjuvant doxorubicin. Local tumour recurrence and pulmonary metastases were diagnosed in one cat 316 days postoperatively. This cat died of chronic renal failure 444 days after limb amputation. The second cat died of an acute pulmonary thromboembolism 41 days postoperatively without evidence of local tumour recurrence or metastatic disease.

Objective: To evaluate postoperative complications, limb function, and tumor control after intercalary resection and reconstruction for preservation of limb and joint function in dogs with high-grade malignant tumors of diaphyseal bone., Study Design: Retrospective study., Animals: Seventeen client-owned dogs., Methods: The bone tumor database and medical records were reviewed (1986-2002) for dogs with diaphyseal tumors treated with intercalary resection and reconstruction with either an allograft or irradiated autograft. Clinical presentation, diagnostic findings, surgical management, and outcome were determined from medical records and telephone interviews with veterinarians and owners. Statistical analyses included chi2 to test associations between intra- and postoperative variables with complications, and Kaplan-Meier survival analysis for disease-free interval, metastasis-free interval (MFI), and median survival time., Results: Intercalary limb-sparing surgery was performed in 17 dogs with diaphyseal tumors: osteosarcoma (OSA) (15), histiocytic sarcoma (1), and solitary metastasis from a pulmonary adenocarcinoma (1). One dog was excluded from further analysis when the spared limb was amputated 4 days postoperatively because of incomplete tumor resection. In 16 dogs, limb function was good to excellent. Complications occurred in 5 dogs (31.3%) and included superficial infection in 2 dogs (12.5%) and implant failure in 4 dogs (25%). All implant failures occurred in the ulna and there was a significant association between implant failure and non-cemented allografts (P=.042). Non-union of 1 or both osteotomies was diagnosed in 10 dogs (83.3%) and, despite lack of clinical signs in all cases, was significantly associated with the use of intracavitary locally released cisplatin (P=.046) and cemented intercalary grafts (P=.046). Local tumor recurrence was diagnosed in 1 dog (6.3%) and metastatic disease in 12 dogs (75.0%), including 10 dogs with OSA. The median MFI was 137 days. The local disease-free and overall limb-salvage rate was 94% and 100%, respectively. Overall median survival time was 393 days and the median survival time for dogs with OSA was 449 days., Conclusion: Intercalary limb-sparing surgery results in better postoperative limb function with fewer and less severe complications than historical reports of dogs treated with non-intercalary limb-sparing surgery., Clinical Relevance: In dogs with diaphyseal tumors, intercalary limb-sparing surgery preserves normal joint function and results in good to excellent limb use with few complications and good local tumor control.

Objective: To evaluate extracorporeal intraoperative radiation therapy (IORT) as a treatment method for limb and joint sparing in dogs with appendicular sarcomas in sites other than the distal aspect of the radius., Study Design: Retrospective study., Animals: Thirteen client-owned dogs., Methods: The bone tumor database and medical records (1998-2002) were reviewed for dogs with primary appendicular bone tumors treated with IORT limb-sparing surgery and adjuvant chemotherapy. The segment of bone containing the tumor was isolated from adjacent soft tissue and an osteotomy performed distant to the tumor. The bone segment was exteriorized, irradiated (70 Gy single fraction), and then stabilized with internal fixation. Adjuvant chemotherapy was administered. Lameness was graded and local and distant tumor control was determined. Associations between intra- and postoperative variables with complications and Kaplan-Meier survival analysis for median disease-free interval and survival time were calculated., Results: Limb function was good or excellent in 10 dogs (77%). Postoperative complications (9 dogs, 69%) included deep infection, fracture of the irradiated bone, and implant failure. Surgical failure was more likely if a single implant was used to stabilize the osteotomized bone and if deep infection developed postoperatively. In 3 dogs, tumors recurred locally within bone in the radiation field. The disease-free and overall success rates of extracorporeal IORT for limb and joint preservation were 46% and 54%, respectively., Conclusions: Extracorporeal IORT provides a novel alternative to traditional techniques for preservation of joint and limb function in dogs with primary appendicular sarcomas. A minimum of 2 implants and intramedullary bone cement should be used to stabilize the osteotomized bone to minimize postoperative complications. Extracorporeal IORT should be used with caution in dogs with tumors of the distal tibia because of a high complication rate. Dogs with tumors in areas of good soft-tissue coverage, such as the humerus and femur, may be good candidates for limb and joint-sparing surgery using extracorporeal IORT., Clinical Relevance: Extracorporeal IORT is a surgical technique that can be used for limb and joint salvage in dogs with primary appendicular sarcomas in sites usually not amenable to traditional limb-sparing techniques.

Background: The rate of local recurrence of osteosarcoma after limb-sparing surgery in dogs and humans has been reported up to 28%. The primary purpose of this study was to determine whether a biodegradable cisplatin-containing implant (OPLA-Pt), inserted into the limb-sparing surgery site at the time of surgery, would decrease the rate of local recurrence. Secondary aims included evaluation of systemic toxicity associated with the release of cisplatin from the implant and identification of prognostic factors associated with limb-sparing surgery for osteosarcoma in dogs., Methods: Eighty dogs with spontaneously occurring osteosarcoma were treated with limb-sparing surgery. They were randomized to receive the biodegradable implant either without cisplatin (control group) or with cisplatin (OPLA-Pt group) and were targeted to receive four doses of an adjuvant cisplatin chemotherapy protocol., Results: Although this was not statistically significant (P =.071), dogs in the OPLA-Pt group were 53.5% less likely to develop local recurrence than dogs in the control group. There were no significant differences in systemic toxicity between treatment arms. Incomplete surgical resection, absence of infection, and fewer than four doses of adjuvant chemotherapy had a significant correlation with local recurrence and survival according to univariate analyses, although only incomplete surgical resection remained significant for local recurrence after multivariate analysis., Conclusions: Local tumor recurrence may be decreased after limb-sparing surgery by use of biodegradable implants impregnated with chemotherapeutic agents.

Objective: To describe the clinical features, surgical and histologic findings, biological behavior, and outcome of dogs with retroperitoneal sarcomas., Design: Retrospective study., Animals: 14 dogs., Procedures: Medical and pathology records from 1992 to 2002 of dogs with tumors originating in the retroperitoneal space were reviewed. Dogs with retroperitoneal tumors originating from the adrenal glands, kidneys, or ureters were excluded. Inclusion criteria included observation of a tumor arising from the retroperitoneal space during exploratory surgery or necropsy and histologic confirmation of tumor type. Details of clinical signs, diagnostic findings, surgical management, and outcome were determined from medical records and telephone interviews with veterinarians and owners., Results: Retroperitoneal sarcoma was diagnosed in 14 dogs, 2 at necropsy and 12 during exploratory surgery. Hemangiosarcoma was the most common histologic diagnosis. Seven dogs had regional extension of the sarcoma into adjacent organs, and 4 dogs had metastatic disease. Grossly complete resection was possible in 6 dogs. Cytoreductive surgery or incisional biopsy was performed in the remaining dogs. Two dogs were treated with palliative radiation therapy (1 intraoperatively and 1 postoperatively). Three dogs received adjunctive chemotherapy, although none completed the targeted course because of development of local recurrence or metastatic disease. Local recurrence was reported in 2 of 12 dogs and metastasis in 10 of 14 dogs. Thirteen dogs died or were euthanatized as a result of the retroperitoneal sarcoma; 1 dog was alive and disease-free 410 days after surgery. Median survival time was 37.5 days., Conclusions and Clinical Relevance: In dogs, retroperitoneal sarcomas are aggressive tumors with a high rate of local recurrence and metastasis, and a poor survival time.

The efficacy and outcome of pulmonary metastatectomy in the management of hypertrophic osteopathy (HO) secondary to metastatic osteosarcoma was retrospectively evaluated in four dogs. Metastatectomy was performed by subpleural enucleation, partial lung lobectomy or complete lung lobectomy through either a median sternotomy or thoracoscopically. Perioperative morbidity was minimal. Clinical signs associated with HO resolved within 24 h of pulmonary metastatectomy in all dogs. Durable remission of symptomatic HO was achieved in all dogs (range, 50-294 days), although recurrence of HO was noted in one dog, 246 days post metastatectomy due to metastasis to the lungs and chest wall. Pulmonary metastatectomy resulted in a rapid and prolonged resolution of HO, and the clinical benefits of metastatectomy potentially exceed the morbidity associated with the surgical procedure.

This paper describes in detail an aggressive rostral maxillectomy procedure in one cat and six dogs, and the postoperative complications and outcomes are reported. The surgeries were performed to attempt complete excision of large and extensive rostral maxillary fibrosarcomas (n=4), squamous cell carcinomas (n=2), or poorly differentiated mesenchymal neoplasia (n=1). The surgeries involved transection of the maxilla at the level of premolar (PM)1 and PM2 in a cat and two dogs, and between PM2 and PM3 in four dogs. There were no intraoperative complications. Complete margins of resection were obtained in all cases. The postoperative appearance was acceptable to owners. Local recurrence was only observed in one dog (10 months after surgery) during a follow-up period of 11 to 66 months (median, 21.5 months).

Objective: To report outcomes after cellophane banding of single congenital portosystemic shunts in dogs and cats., Study Design: Retrospective study of sequential cases., Animals: One hundred and six dogs and five cats., Methods: Medical records were reviewed for breed, sex, age at surgery, shunt anatomy, results of pre- and postoperative biochemical analysis, development of postligation neurologic dysfunction, portal hypertension or other serious complications, and the owners' perception of their animal's response to surgery., Results: Ninety-five dogs and all 5 cats had extrahepatic shunts. Eleven dogs had intrahepatic shunts. Six dogs (5.5%) died as a result of surgery from portal hypertension (2 dogs), postligation neurologic dysfunction (2), splenic hemorrhage (1) and suspected narcotic overdose (1). Serious complications were more common in dogs with intrahepatic shunts than those with extrahepatic shunts (P=.002). Postligation neurologic dysfunction necessitated treatment in 10 dogs and 1 cat; 8 dogs and the cat survived. Clinical signs attributed to portosystemic shunting resolved or were substantially attenuated in all survivors. Postoperative serum bile acid concentrations or results of ammonia tolerance testing were available for 88 animals; 74 (84%) were normal and 14 (16%) were abnormal. Multiple acquired shunts were documented in two animals., Conclusions: Cellophane banding is a safe and effective alternative to other methods of attenuation., Clinical Relevance: Slow occlusion of portosystemic shunts using a variety of methods is being evaluated world wide. Cellophane banding is a relatively simple procedure with comparable safety and efficacy to previously reported techniques.

An eight-year-old, male castrated basset hound presenting with a three-month history of lethargy was examined. Diagnostic tests including radiography and ultrasonography showed a right-sided renal mass. A 99mTc diethylenetriamine penta-acetic acid scan demonstrated that this kidney was non-functional. At surgery, invasion of the caudal vena cava was found, and the renal segment of the vena cava and the right kidney were resected. The left renal vein was anastomosed to the more proximal vena cava using a polytetrafluoroethylene graft, and the dog recovered well. Two days postsurgery, the dog suffered an acute episode of aspiration pneumonia and was euthanased. The renal mass was diagnosed as lymphoma on histopathology.

Objective: To describe the use of skin-fold advancement flaps for covering large skin defects in dogs and cats., Study Design: Clinical study., Animals: Eight client-owned animals: 6 dogs and 2 cats., Methods: Six dogs and 2 cats underwent reconstruction of soft-tissue wounds resulting from traumatic, neoplastic, or infectious lesions. Skin-fold flaps were created by division of the medial and lateral attachment to the proximal limb or the dorsal and ventral attachment to the trunk, enabling closure of adjacent defects on the trunk or proximal limb, respectively., Results: Skin-fold flaps proved effective for closing defects in all animals. Necrosis of a portion of the flap occurred in 2 dogs due to technical errors, but the resultant defects remained amenable to primary closure. All wounds ultimately healed primarily, without major complications., Conclusion and Clinical Relevance: The skin-fold advancement flap is a versatile technique that lends itself to use in a variety of locations, depending on which attachments are divided. The clinical results are comparable with those reported for axial pattern and subdermal plexus flaps., (Copyright 2001 by The American College of Veterinary Surgeons)

A young, female Maltese dog was presented with intermittent vomiting of bile. Biochemical evidence of persistent mild hepatopathy had been present for 11 months. Exploratory celiotomy was performed. Absence of the gallbladder with malformation of the quadrate lobe of the liver was identified. There was histological evidence of bile duct proliferation and portal fibrosis.