Value, Limitations, and Recommendations for Grading of Canine Cutaneous Mast Cell Tumors: A Consensus of the Oncology-Pathology Working Group.

One of the primary objectives of the Oncology Pathology Working Group (OPWG), a joint initiative of the Veterinary Cancer Society and the American College of Veterinary Pathologists, is for oncologists and pathologists to collaboratively generate consensus documents to standardize aspects and provide guidelines for oncologic pathology. Consensus is established through review of relevant peer-reviewed literature relative to a subgroup's particular focus. In this article, the authors provide a critical review of the current literature for grading of canine cutaneous mast cell tumors, suggest guidelines for reporting, and provide recommendations for its clinical interpretation. The article mainly focuses on histologic grading, but relevant information on mitotic count and cytological grading are also discussed. This document represents the opinions of the working group and the authors but does not constitute a formal endorsement by the American College of Veterinary Pathologists or the Veterinary Cancer Society.

The pinna composite flap for wound reconstruction in a dog.

OBJECTIVE: To report the surgical technique and outcome of the use of a pinna composite flap for reconstruction of a wound defect following wide surgical resection of a mast cell tumor. ANIMALS: A 4-year-old female spayed golden doodle. STUDY DESIGN: Clinical case report. METHODS: A dog with a histologically confirmed cutaneous mast-cell tumor at the base of the ear was treated with a wide surgical resection, including total ear canal ablation and lateral bulla osteotomy. The defect could not be closed primarily and, as a result, the defect was reconstructed with a composite pinna flap. RESULTS: Partial avascular necrosis of the distal aspect of the composite flap required debridement and closure 13 days after the initial surgery. The flap was fully healed at 27 days postoperatively. The dog had facial nerve paralysis, which had not resolved by 45 weeks postoperatively. CONCLUSION: The surgical technique described in this report is novel. The use of the pinna as a composite flap is a novel reconstructive option for dorsal and dorsolateral head wounds.

Clinical findings and outcomes of 153 dogs surgically treated for intestinal intussusceptions.

OBJECTIVE: To describe perioperative characteristics and outcomes of dogs surgically treated for intestinal intussusception. STUDY DESIGN: Multi-institutional, retrospective study. ANIMALS: One hundred fifty-three client-owned dogs with intestinal intussusception. METHODS: Dogs were included when they had undergone surgical treatment of a confirmed intestinal intussusception. Medical records were reviewed for demographics and clinical data, including surgical complications (graded 1-4). Follow-up was obtained via telephone interview with owners and referring veterinarians. RESULTS: Dogs had a median age of 10 months (range, 2-156), and the most common location for intussusception was ileocolic (66/153 [43%]). Most cases had no identifiable cause (104/155 [67%]). Intestinal resection and anastomosis (IRA) was performed in 129 of 153 (84%) dogs; enteroplication was performed in 28 of 153 (18%) dogs, including 13 with and 15 without IRA. Intraoperative complications occurred in 10 of 153 (7%) dogs, all involving intestinal damage during attempted manual reduction. The median duration of follow-up after discharge was 334 days (interquartile range, 15-990; range, 1-3302). Postoperative complications occurred in 53 of 153 (35%) dogs, including 22 of 153 (14%) with severe (grade 3 or 4) events. Diarrhea, regurgitation, and septic peritonitis were the most common postoperative complications; intussusception recurred in four of 153 (3%) dogs, all within 72 hours postoperatively. Fourteen-day postoperative mortality rate was 6%. CONCLUSION: Surgical treatment of intestinal intussusception was curative in most dogs, even when an underlying cause was not identified. Surgical complications were common, including a 14% risk of life-threatening short-term complications. CLINICAL SIGNIFICANCE: Surgical treatment of intestinal intussusception offers an excellent prognosis, but the potential life-threatening complications should be considered.

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.

Outcomes and prognostic variables associated with central division hepatic lobectomies: 61 dogs.

OBJECTIVE: To determine the outcome and prognostic variables associated with long-term survival and complications in dogs undergoing hepatic lobectomy of the central division. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Sixty-one client-owned dogs with central division masses. METHODS: Medical records of dogs undergoing hepatic lobectomy of the central division from January 1, 2000 to January 1, 2015 were reviewed for signalment, clinical signs, preoperative staging, preoperative cytology or biopsy results, date of procedure, location of mass, surgical technique, whether cholecystectomy or cholecystopexy was performed, complications, histopathologic diagnosis and margin evaluation, date of local recurrence or detection of metastatic disease, and survival. RESULTS: Hilar resection was associated with increased intraoperative and postoperative complications. Intraoperative complications occurred in 29 dogs, with 20 dogs experiencing intraoperative hemorrhage. Nineteen dogs required transfusions. Immediate postoperative complications occurred in 20 dogs. Perioperative mortality rate was 11%, and 2-week mortality rate was 14.7%. The median survival time for dogs with hepatocellular carcinoma (HCC) was not reached. The 1- and 3-year censored survival rates for dogs with HCC was 82.1% and 82.1%, respectively. Margin status did not impact survival time. CONCLUSION: Hepatic lobectomy of the central division was associated with hemorrhage in approximately 33% of dogs, but there was a relatively low perioperative mortality rate. Hepatic lobectomy for HCC resulted in long-term survival, regardless of margin status. CLINICAL SIGNIFICANCE: Surgeons should anticipate the requirement for blood products in dogs that may require hepatic lobectomy of the central division. Long-term survival can be expected after surgical treatment of HCC, regardless of margin status.

Perioperative characteristics, histological diagnosis, and outcome in cats undergoing surgical treatment of primary hyperparathyroidism.

OBJECTIVE: To report perioperative characteristics, complications, histopathologic diagnosis and outcome in cats undergoing surgical treatment for primary hyperparathyroidism (PHPT). STUDY DESIGN: Multi-institutional, retrospective case series. ANIMALS: Thirty-two client-owned cats. METHODS: Medical records of cats treated with surgical removal of 1 or more parathyroid gland(s) with confirmed histopathologic evaluation were reviewed. Cats were divided into preoperative ionized calcium (iCa) groups corresponding to the 33rd, 67th, and 100th percentiles of the preoperative iCa results of the study population. Follow-up consisted of phone conversation with owners or primary veterinarian. RESULTS: Ionized calcium was above reference range in all cats (median 1.8 mmol/L [interquartile range, 1.5-1.9]). Abnormal tissue was excised after cervical exploration in all cats. The most common histopathologic diagnoses were parathyroid adenoma in 20 of 32 (62.5%) cats and parathyroid carcinoma in 7 of 32 (21.9%) cats. At discharge, 6 of 32 (18.8%) cats had hypercalcemia, 5 of 32 (15.6%) had hypocalcemia, and 21 of 32 (65.6%) were normocalcemic. Preoperative iCa did not correlate with postoperative iCa. The median follow-up time was 332 days (range, 7-3156). Overall median survival time was 1109 days (95% CI, 856-1332). Survival time was not associated with preoperative iCa group, hypocalcemia at discharge, hypercalcemia at discharge, or diagnosis of carcinoma. CONCLUSION: In this cohort of cats, parathyroid adenoma was the most common cause of PHPT, and surgical treatment resulted in very good median survival time. Preoperative iCa was not predictive of postoperative hypocalcemia. CLINICAL SIGNIFICANCE: Surgical parathyroidectomy for treatment of PHPT in cats provides a favorable prognosis.

Perioperative complications and outcome after surgery for treatment of gastric carcinoma in dogs: A Veterinary Society of Surgical Oncology retrospective study of 40 cases (2004-2018).

OBJECTIVE: To describe the clinical characteristics, perioperative complications, and outcomes in dogs surgically treated for gastric carcinoma. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Forty client-owned dogs with histologically confirmed gastric carcinoma. METHODS: Medical records were reviewed for preoperative diagnostics, surgery, histopathology, postoperative complications, adjuvant chemotherapy, disease progression, and survival. Variables were assessed for associations with outcome by using Cox proportional hazards regression analysis. RESULTS: Surgical treatment included partial gastrectomy (28 dogs), Billroth I (9 dogs), subtotal gastrectomy (2 dogs), and submucosal resection (1 dog). Major postoperative complications occurred in 8 of 40 dogs, including septic peritonitis secondary to dehiscence in 4 dogs. The median progression free interval was 54 days, and the median survival time (MST) was 178 days (range, 1-1902). According to multivariable analysis results, experiencing an intraoperative complication was associated with an increased risk of death (hazard ratio [HR] 3.5, 95% CI 1.1-9.8, P = .005), and administration of adjuvant chemotherapy correlated with an improved survival (HR 0.4, 95% CI 0.2-0.9, P = .03). CONCLUSION: In this population of dogs, MST exceeded historically reported data, major postoperative complication rates were comparable to established literature, and administration of adjuvant chemotherapy was associated with improved survival. CLINICAL SIGNIFICANCE: Results from this study may be used to counsel owners more accurately regarding prognosis for dogs undergoing surgical excision for gastric carcinoma.

Total prostatectomy as a treatment for prostatic carcinoma in 25 dogs.

OBJECTIVE: To describe the complications and outcome after total prostatectomy in dogs with histologically confirmed prostatic carcinoma. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: 25 client-owned dogs. METHODS: Medical records of dogs undergoing total prostatectomy were reviewed from 2004 to 2016. Data retrieved included signalment, presenting signs, preoperative clinical findings, laboratory data, diagnostic imaging, surgical technique, histologic diagnosis, postoperative complications, occurrence of postoperative metastasis, and survival. RESULTS: Twenty-five dogs underwent total prostatectomy for prostatic carcinoma. Urinary anastomotic techniques included urethrourethral anastomosis in 14 dogs, cystourethral anastomosis in 9 dogs, ureterocolonic anastomosis in 1 dog, and anastomosis between the bladder neck and penile urethra in 1 dog. All dogs survived to discharge. Fifteen dogs were diagnosed with transitional cell carcinoma, 8 dogs with prostatic adenocarcinoma, 1 with prostatic cystadenocarcinoma, and 1 with an undifferentiated carcinoma. Permanent postoperative urinary incontinence was present in 8 of 23 dogs. The median survival time was shorter in dogs with extracapsular tumor extension compared with those with intracapsular tumors. The overall median survival time was 231 days (range, 24-1255), with 1- and 2-year survival rates equal to 32% and 12%, respectively. CONCLUSION AND CLINICAL SIGNIFICANCE: Total prostatectomy, combined with adjunct therapies, prolongs survival and lowers complication rates compared to previous reports of dogs with prostatic carcinoma. It should be noted, however, that case selection likely played a significant role in postoperative outcome.

Perioperative Mortality and Long-Term Survival in 80 Dogs and 32 Cats Undergoing Excision of Thymic Epithelial Tumors.

OBJECTIVE: To examine perioperative mortality, long-term survival, causes of death, and prognostic factors for dogs and cats undergoing surgical excision of thymic epithelial tumors (TETs). STUDY DESIGN: Multi-institutional case series. ANIMALS: Eighty dogs and 32 cats. METHODS: Follow-up information was obtained for dogs and cats that underwent surgical excision of a TET between 2001 and 2012. RESULTS: Perioperative mortality was 20% in dogs and 22% in cats. No independent risk factors for perioperative mortality were identified. The estimated median survival time for all dogs was 1.69 years (95% CI 0.56-4.32) and the 1- and 4-year survival rates were 55% (95% CI 44-67) and 44% (95% CI 32-56). The estimated median survival time for all cats was 3.71 years (95% CI 0.56-unestimatable) and the 1- and 4-year survival rates were 70% (95% CI 53-87) and 47% (95% CI 0-100). Of animals that survived to discharge, 42% of dogs and 20% of cats eventually died of TET-related causes. The presence of paraneoplastic syndromes (hazard ratio [HR] 5.78, 95% CI 1.64-20.45, P = .007) or incomplete histologic margins (HR 6.09, 95% CI 1.50-24.72, P = .01) were independently associated with decreased survival in dogs. No significant predictors of survival were identified in cats. Conclusions regarding the effect of chemotherapy or radiation therapy could not be made. CONCLUSIONS: While there is substantial risk of perioperative death in dogs and cats undergoing surgery for TETs, many animals that survive to discharge have prolonged survival. Survival is significantly decreased in dogs with paraneoplastic syndromes or incomplete histologic margins.

Lateral caudal axial pattern flap in 13 dogs.

OBJECTIVE: To describe the frequency and extent of complications associated with lateral caudal axial pattern flaps used to cover large traumatic or excision skin defects on the dorsum, gluteal, and perineal region in 13 dogs. STUDY DESIGN: Case series. ANIMALS: Thirteen client-owned dogs. METHODS: Medical records from 8 institutions were reviewed for dogs treated with a lateral caudal axial pattern flap, including cases in which the procedure was combined with other reconstructive techniques. The flap length relative to the tail length, location of tail skin incision, size and cause of the defect, and short- and long-term complications were recorded. RESULTS: Thirteen dogs were included, 11 with tumors and 2 with traumatic skin loss. The mean estimated length of the flap relative to tail length was 51% (range 33-70%). Four dogs had wound complications. This included 2 dogs with minor postoperative wound complications (mild distal dehiscence) that did not require surgical revision and 2 dogs with major complications that required surgical revision. Two of these 4 dogs had distal flap necrosis, one was revised surgically and one was managed conservatively. In these 2 dogs, the flap length was estimated as 80% and 65% of the tail length, respectively. At 30 days, flaps in all dogs were completely healed. No long-term complications were recorded in any dog. For some dogs, the reconstruction was not obvious, with only the change in hair direction and color noticeable. CONCLUSION: Lateral caudal axial pattern flap is a reconstructive option for gluteal, dorsal, and perineal skin defects in dogs. Distal flap necrosis and dehiscence due to wound infection occurred in 4 dogs that required additional wound care but not always surgical revision.

Hemipelvectomy: outcome in 84 dogs and 16 cats. A veterinary society of surgical oncology retrospective study.

OBJECTIVE: To report clinical findings, perioperative complications and long-term outcome in dogs and cats that had hemipelvectomy surgery for treatment of neoplasia. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Dogs (n = 84) and cats (16). METHODS: Medical records (January 2000 to December 2009) of dogs and cats that had hemipelvectomy at participating institutions were reviewed. Postoperative progress and current status of the patient at the time of the study was determined by either medical record review, or via telephone contact with the referring veterinarian or owner. RESULTS: Complications were infrequent and usually minor. Hemorrhage was the main intraoperative complication; 2 dogs required blood transfusion. One dog developed an incisional hernia. In dogs, hemangiosarcoma had the worst prognosis with a median survival time (MST) of 179 days. MST for chondrosarcoma (1232 days), osteosarcoma (533 days), and soft tissue sarcoma (373 days) were not statistically different. Median disease-free interval (DFI) for local recurrence of all tumor types was 257 days. Cats had 75% survival at 1 year, which was significantly longer than dogs. CONCLUSIONS: Survival times for most tumor types can be good, but surgical margins should be carefully evaluated to ensure complete tumor removal. Adjuvant therapies may be advisable particularly for dogs to reduce rates of local recurrence or distant metastasis.

Updates in Surgical Oncology.

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.

Risk factors influencing death prior to discharge in 302 dogs undergoing unilateral adrenalectomy for treatment of primary adrenal gland tumours.

Adrenalectomies for canine adrenal tumours are associated with peri-operative morbidity and mortality. Objectives of this study included assessing the prognostic value of tumour- or surgery-related variables in predicting peri-operative mortality and overall survival in dogs undergoing adrenalectomies for primary adrenal tumours as well as pre-treatment with phenoxybenzamine on survival to discharge with pheochromocytomas specifically. A multi-institutional retrospective cohort study was performed across nine institutions. Electronic medical record searches identified 302 dogs which met the inclusion criteria. Data collected included dog-related, tumour-related, treatment-related, surgery-related, and outcome variables. Univariate and multivariable logistic regression and cox proportional hazards models were used to identify variables associated with death prior to discharge and tumour-related survival. Overall, 87% of dogs survived to discharge with a tumour-related survival time of 3.96 years. Post-operative complications were reported in 25%. Increased surgical time (p = 0.002) and pre-surgical medical treatment other than phenoxybenzamine (p = 0.024) were significantly associated with increased peri-operative mortality while ureteronephrectomy (p = 0.021), post-operative pancreatitis (p = 0.025), and post-operative aspiration pneumonia (p < 0.001) were significantly associated with decreased overall survival. Phenoxybenzamine pretreatment had no effect on peri-operative mortality. Thirty-seven of 45 (82%) dogs with pheochromocytomas not pretreated survived to discharge, and 50 of 59 (85%) dogs with pheochromocytomas pretreated with phenoxybenzamine survived to discharge (p = 0.730). This study provides information on risk factors for death prior to discharge and tumour-related survival that may help guide clinical management and owner expectations. In addition, the study findings challenge the previously reported benefit of phenoxybenzamine for pretreatment of dogs undergoing adrenalectomies for pheochromocytomas.

Outcome with surgical treatment of canine soft tissue sarcoma in the region of the ischiatic tuberosity: A veterinary society of surgical oncology retrospective study.

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.

Risk factors and outcome in dogs with recurrent massive hepatocellular carcinoma: A Veterinary Society of Surgical Oncology case-control study.

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.

Predictors of outcome in dogs treated with adjuvant carboplatin for appendicular osteosarcoma: 65 cases (1996-2006).

OBJECTIVE: To determine outcomes and prognostic factors for those outcomes in dogs with appendicular osteosarcoma treated with curative-intent surgery and adjuvant carboplatin. DESIGN: Retrospective case series. ANIMALS: 65 client-owned dogs with appendicular osteosarcoma and no evidence of gross metastatic disease at the time of diagnosis. PROCEDURES: Medical records of dogs that underwent limb amputation or distal ulnectomy and adjuvant carboplatin treatment for appendicular osteosarcoma were reviewed. Adverse effects of chemotherapy and findings regarding preoperative biopsy specimens and postoperative diagnostic imaging were recorded. Signalment, clinical history, and chemotherapy variables were evaluated for associations with outcome. Histologic grade and other variables were evaluated for association with outcome for 38 tumors that were retrospectively graded. RESULTS: The median disease-free interval was 137 days (95% confidence interval [CI], 112 to 177 days). Median survival time was 277 days (95% CI, 203 to 355 days). The 1-, 2-, and 3-year survival rates were 36%, 22%, and 19%, respectively. None of the chemotherapy variables were associated with outcome. Preoperative proteinuria was the only clinical variable associated with poor outcome. Histologic features of tumors associated with a poor outcome were intravascular invasion, mitotic index > 5 in 3 microscopic hpfs, and grade III classification. CONCLUSIONS AND CLINICAL RELEVANCE: Carboplatin administration was well tolerated and resulted in a disease-free interval and median survival time similar to those of other published protocols.

Outcome after repair of a sarcoma-related pathologic fracture in dogs: a Veterinary Society of Surgical Oncology Retrospective Study.

OBJECTIVE: To report outcome in dogs after internal fixation of a sarcoma-related pathologic fracture of the appendicular skeleton. STUDY DESIGN: Multi-institutional case series. ANIMALS: Dogs (n=16). METHODS: Medical records of participating VSSO members were reviewed for dogs with pathologic fracture associated with a confirmed bone sarcoma of the appendicular skeleton repaired by external or internal fixation. Dogs were included if they had a histological diagnosis of osteosarcoma or sarcoma and excluded if they had radiation before fracture. Data collected were analyzed for signalment, fracture location, staging performed, method of fracture fixation, histopathology, adjunctive treatment and outcome. RESULTS: Signalment and fracture location of 16 dogs that met the inclusion criteria was similar to dogs with appendicular OSA without fracture. One of 14 dogs had pulmonary metastasis and 3 of 5 dogs had bone metastasis. Bone plate or interlocking nail were used for repair in 12 dogs. Limb use immediately after surgery in 13 dogs was good (4), weight-bearing but lame (7) and non-weight bearing (2). Adjunctive therapy was administered in 5 dogs (chemotherapy, 3; radiation, 4; pamidronate, 3). Survival time ranged from 18 to 897 days; median survival was 166 days. CONCLUSIONS: Repair of pathologic fracture can result in palliation and prolonged survival.

Effect of perioperative desmopressin in cats with mammary carcinoma treated with bilateral mastectomy.

Perioperative administration of desmopressin has shown to significantly decrease rates of local recurrence and metastasis, and increase survival times in dogs with grade II and III mammary carcinomas. The objective of this study was to compare the oncologic outcome of cats with mammary carcinoma treated with bilateral mastectomy with or without perioperative administration of desmopressin. Medical records from nine veterinary institutions were searched to identify cats diagnosed with mammary carcinoma treated with bilateral mastectomy. Sixty cats treated with single-session or staged bilateral mastectomy were included. There were no significant differences in oncologic outcomes found between cats treated and not treated with desmopressin. No adverse effects were seen in any of the cats treated with perioperative desmopressin. Postoperative complications occurred in 18 cats (38.3%) treated with single-session bilateral mastectomy and in three cats (23.1%) treated with staged bilateral mastectomy (P = .48). Histologic grade and a modification of a proposed five-stage histologic staging system were both prognostic for disease-free interval. Incomplete histologic excision was associated with significantly increased rates of metastasis and tumour progression, and a shorter median survival time (MST). Cats that developed local recurrence also had a significantly shorter MST. The results of this study do not support the use of perioperative desmopressin to improve outcome when performing bilateral mastectomy for the treatment of mammary carcinoma in cats.

Outcomes of cats treated with maxillectomy: 60 cases. A Veterinary Society of Surgical Oncology retrospective study.

Maxillectomy is poorly described for the management of oral tumours in cats and is occasionally not recommended because of the high complication rate and sub-optimal outcome reported in cats treated with mandibulectomy. The purpose of this study was to retrospectively evaluate the complications and oncologic outcome in cats treated with maxillectomy. Sixty cats were included in the study. Maxillectomy procedures included unilateral rostral (20.0%), bilateral rostral (23.3%), segmental (10.0%), caudal (20.0%) and total unilateral maxillectomy (26.7%). Intra-operative and post-operative complications were reported in 10 (16.7%) and 34 (56.7%) cats, respectively. The most common post-operative complications were hyporexia (20.0%) and incisional dehiscence (20.0%). The median duration of hyporexia was 7 days. Benign tumours were diagnosed in 19 cats (31.7%) and malignant tumours in 41 cats (68.3%). Local recurrence and metastatic rates were 18.3% and 4.9%, respectively; the median progression-free interval (PFI) was not reached. The disease-related median survival time was not reached overall or for either benign or malignant tumours. The 1- and 2-year survival rates were, respectively, 100% and 79% for cats with benign tumours, 89% and 89% for cats with malignant tumours, 94% and 94% for cats with fibrosarcomas, 83% and 83% for cats with squamous cell carcinomas, and 80% and 80% for cats with osteosarcomas. Poor prognostic factors included mitotic index for PFI, adjuvant chemotherapy for both PFI and survival time, and local recurrence for survival time. Maxillectomy is a viable treatment option for cats resulting in good local tumour control and long survival times.

Evaluation of outcomes following subtotal colectomy for the treatment of idiopathic megacolon in cats.

OBJECTIVE: To evaluate outcomes in cats undergoing subtotal colectomy for the treatment of idiopathic megacolon and to determine whether removal versus nonremoval of the ileocecocolic junction (ICJ) was associated with differences in outcome. ANIMALS: 166 client-owned cats. PROCEDURES: For this retrospective cohort study, medical records databases of 18 participating veterinary hospitals were searched to identify records of cats with idiopathic megacolon treated by subtotal colectomy from January 2000 to December 2018. Data collection included perioperative and surgical variables, complications, outcome, and owner perception of the procedure. Data were analyzed for associations with outcomes of interest, and Kaplan-Meier survival time analysis was performed. RESULTS: Major perioperative complications occurred in 9.9% (15/151) of cats, and 14% (12/87) of cats died as a direct result of treatment or complications of megacolon. The median survival time was not reached. Cats with (vs without) a body condition score < 4/9 (hazard ratio [HR], 5.97), preexisting heart disease (HR, 3.21), major perioperative complications (HR, 27.8), or long-term postoperative liquid feces (HR, 10.4) had greater hazard of shorter survival time. Constipation recurrence occurred in 32% (24/74) of cats at a median time of 344 days and was not associated with retention versus removal of the ICJ; however, ICJ removal was associated with long-term liquid feces (OR, 3.45), and a fair or poor outcome on owner assessment (OR, 3.6). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that subtotal colectomy was associated with long survival times and a high rate of owner satisfaction. Removal of the ICJ was associated with less favorable outcomes in cats of the present study.