Comparative aspects of targeted sentinel lymph node mapping in veterinary and human medicine: opportunities for future research

There is a significant overlap in the genetic, metabolic and epigenetic alterations between human and companion animal cancers, including those of the oral cavity, breast, bladder, skin, lungs and pancreas. In many cancer types, the identification and removal of affected lymph nodes are essential for accurate cancer management, including treatment and prognosis. Historically, lymphadenectomy and subsequent radical resection based on regional anatomy, palpation and lymph node aspirates were considered sufficient; however, modern approaches with sentinel lymph node mapping (SLN) mapping have increased the accuracy of surgical decision-making. Preoperative and intraoperative SLN mapping techniques in veterinary patients parallel those used in human medicine. While many of these techniques are highly successful, the main challenges with current methodologies are their sensitivity and specificity for the presence of cancer, which can be overcome via precision medicine and targeted SLN mapping agents. Given the large population of dogs and cats with cancer, the crossover of knowledge between species can help to deepen our understanding of many of these cancers and can be useful in evaluating new drugs and/or therapies. In this review, we discuss SLN mapping techniques in veterinary medicine and the concept of precision medicine as it relates to targeted SLN mapping imaging agents. The large number of companion animals affected by cancer is an underutilized resource to bridge the translational gap and we aim to provide a reference for the use of dogs and cats as a comparative model for human SLN mapping.

Reason for euthanasia in dogs with urothelial carcinoma treated with chemotherapy or radiation therapy or both: A retrospective observational study

BACKGROUND

Clients want to know the ultimate cause of death in their pet after cancer treatment. The cause of euthanasia and investigation of urinary obstruction in treated dogs with urothelial carcinoma (UC) has not been specifically reported in veterinary literature.

HYPOTHESIS/OBJECTIVES

Our hypothesis was that the majority of treated dogs with UC are euthanized secondary to primary tumor factors, such as urinary obstruction.

ANIMALS

Fifty-nine client-owned dogs diagnosed with UC.

METHODS

Retrospective observational study on clinical signs and disease at euthanasia of dogs with UC treated by radiation therapy or chemotherapy or both.

RESULTS

The median overall survival time (OST) of all dogs was 339 days (range, 17-1996; 95% confidence interval [CI], 185-392; interquartile range [IQR], 112-505). Of dogs deemed to have been euthanized because of UC (50/59, 85%), the primary cause was considered to be local progression in 31/50 (62%), most often because of perceived complete or partial urinary obstruction (24/31, 77%). No variables were found to be predictive of urinary obstruction. The overall documented metastatic rate was 56%. In dogs euthanized because of UC, metastasis was deemed to be the cause in 19/50 (38%) dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Regardless of the type of treatment, UC in dogs has a poor prognosis and there is a continuing need to improve treatments that focus on local control of the primary tumor, given its high contribution to the decision for euthanasia. Proactive management to avoid the high frequency of urinary obstruction may be worthy of future investigation.

Adrenal tumors treated by adrenalectomy following spontaneous rupture carry an overall favorable prognosis: retrospective evaluation of outcomes in 59 dogs and 3 cats (2000-2021)

OBJECTIVE

To conduct a retrospective multi-institutional study reporting short- and long-term outcomes of adrenalectomy in patients presenting with acute hemorrhage secondary to spontaneous adrenal rupture.

ANIMALS

59 dogs and 3 cats.

METHODS

Medical records of dogs and cats undergoing adrenalectomy between 2000 and 2021 for ruptured adrenal masses were reviewed. Data collected included clinical presentation, preoperative diagnostics, surgical report, anesthesia and hospitalization findings, histopathology, adjuvant treatments, and long-term outcome (recurrence, metastasis, and survival).

RESULTS

Median time from hospital admission to surgery was 3 days, with 34% of surgeries being performed emergently (within 1 day of presentation). Need for intraoperative blood transfusion was significantly associated with emergent surgery and presence of active intraoperative hemorrhage. The short-term (≤ 14 days) complication and mortality rates were 42% and 21%, respectively. Negative prognostic factors for short-term survival included emergent surgery, intraoperative hypotension, and performing additional surgical procedures. Diagnoses included adrenocortical neoplasia (malignant [41%], benign [12%], and undetermined [5%]), pheochromocytoma (38%), a single case of adrenal fibrosis and hemorrhage (2%), and a single case of hemangiosarcoma (2%). Local recurrence and metastasis of adrenocortical carcinoma were confirmed in 1 and 3 cases, respectively. Overall median survival time was 574 days and 900 days when short-term mortality was censored. No significant relationship was found between histopathological diagnosis and survival.

CLINICAL RELEVANCE

Adrenalectomy for ruptured adrenal gland masses was associated with similar short- and long-term outcomes as compared with previously reported nonruptured cases. If hemodynamic stability can be achieved, delaying surgery and limiting additional procedures appear indicated to optimize short-term survival.

Effect of volume and methylene blue on fluorescence intensity and transit of indocyanine green for sentinel lymph node mapping in a simulated feline tumor model

OBJECTIVE

To compare the effect of volume and solution on transit time and fluorescence intensity (FI) using near-infrared fluorescence imaging (NIRF) in a simulated tumor model in cats. Secondarily, to describe SLN mapping with indocyanine green (ICG) NIRF and report any adverse effects of intradermally injected ICG in cats.

ANIMALS

7 healthy purpose-bred domestic shorthaired male cats.

METHODS

Cats were randomly divided into 2 groups (ICG or ICG + methylene blue [MB]). Transit time and FI were determined for 1 or 2 mL solutions injected intradermally in 4 quadrants around a simulated tumor. Following massage, fluorescence intensity was quantified by calculating the corrected total ROI fluorescence using ImageJ software. Cats were monitored for adverse effects up to 4 weeks post-injection.

RESULTS

A larger solution volume had decreased transit times to the SLN (P = .001). There was no significant difference in transit times between ICG and ICG-MB. ICG demonstrated a greater FI (P = .001) in the SLN compared to ICG-MB. Methylene blue did not percutaneously fluoresce under NIRF. The volume of the solution did not significantly affect FI. No adverse reactions were reported.

CLINICAL RELEVANCE

Increased volume of ICG may aid in rapid percutaneous lymphatic tracking from tumor to SLN. Indocyanine green alone may be preferred over ICG-MB for greater visualization of the SLN. Intradermal injections of ICG and ICG-MB were well-tolerated in healthy cats with no significant complications. Clinical evaluation of this technique in an impaired lymphatic system, as seen in cancer patients, should be assessed in future research.

Quantification of circulating tumour cells over time in dogs with appendicular osteosarcoma

Enumeration of circulating tumour cells (CTC) has shown promise for prognostication and guidance of therapeutic decisions in human cancers. The objective of this study was to enumerate CTC over time in dogs with naturally occurring osteosarcoma (OSA), and to determine correlation with patient outcome. Twenty-six dogs with OSA and no evidence of metastatic disease at the time of amputation were enrolled. Dogs were assessed for lung metastases and CTC prior to and following amputation, and at each chemotherapy visit. Twenty-one dogs completed the study. Nineteen dogs were euthanized and two were alive and free of metastases. Overall survival time ranged from 88 to 1058 days (median survival time (MST) 374 days). Increased serum alkaline phosphatase activity, advanced age, and higher body weight were significantly associated with lower MST. Dogs with OSA had a mean of 356 (0 to 4443) CTC/106 leukocytes. In 12 of 15 dogs that developed radiographic evidence of metastasis, a pre-metastatic CTC spike was retrospectively detectable on average 36.5 (1-100 days) days prior to metastasis and was associated with significantly shorter MST (301 ± 64 vs. 626 ± 55 days; p = .0107). In a multivariable analysis, dogs with a CTC spike were 10× more likely to die compared with those without. These results suggest that a spike in CTC frequency precedes detection of metastasis in dogs with OSA and is associated with shorter survival. More frequent enumeration of CTC in a larger cohort of dogs with OSA may be warranted.

Perioperative complications and outcomes following partial ear canal ablation and lateral bulla osteotomy in pet rabbits: 20 cases (2009-2021)

OBJECTIVE

To investigate the perioperative complications and outcomes of rabbits undergoing partial ear canal ablation and lateral bulla osteotomy for treatment of chronic otitis.

MATERIALS AND METHODS

Surgical logbooks were searched to identify rabbits that underwent partial ear canal ablation and lateral bulla osteotomy between December 2009 and September 2021. Data collected included signalment, history, clinical signs, historical and current medical management, physical examination findings, preoperative diagnostic imaging and aural bacterial culture results, surgical procedure information, duration of hospitalisation, complications and final outcome.

RESULTS

Twenty rabbits with chronic, medically unresponsive otitis underwent 27 partial ear canal ablation and lateral bulla osteotomies. Ten rabbits had pre-existing neurologic deficits and 17 had an ear base abscess at the time of surgery. A total of 13 (65%) rabbits developed at least one complication, either in the perioperative period or between discharge and recheck. Three of these rabbits (15%) underwent revision surgery for persistent or recurrent ear base abscess. Complete resolution of clinical signs ultimately occurred in 12 (60%) rabbits. Three (15%) rabbits showed improved but not completely resolved clinical signs (three facial asymmetry). Five (25%) rabbits died of causes potentially related to chronic otitis and/or partial ear canal ablation and lateral bulla osteotomy; two of these rabbits had undergone revision surgery.

CLINICAL SIGNIFICANCE

Although this study reports a high complication rate (65%), most complications resolved, with 15 (75%) rabbits having a good to excellent final outcome. Since the majority of rabbits in this study had chronic and severe ear disease, further studies are required to determine if surgical intervention earlier in the disease process could result in a lower complication rate.

Shelter Worker's Experiences and Perceptions of Capacity for Care (C4C)

Capacity for Care (C4C) is a shelter management strategy which utilizes managed intake to optimize in-shelter populations based on housing capacity and available resources. The purpose of this study was to 1) understand staff experiences using managed intake, 2) explore staff perceptions of how the C4C model has been regarded by other staff at their facility, and 3) explore the response of community members who are attempting to relinquish their cats, as perceived by the staff who are communicating with cat owners and scheduling relinquishment. Participants recruited from shelters who practiced C4C participated in a semi-structured interview and completed a written survey to share their experiences and perceptions of C4C. Based on the perceptions of the participants, evidence suggests the waitlist may decrease the admission of owned cats to the shelter as a result of advising cat owners about alternatives to relinquishment. The findings suggest that more research is needed to understand the potential impacts of managed intake, as an element of C4C, on the welfare of cats in the community who are waiting to be admitted to a shelter.

Hemangiosarcoma of the nasal planum in cats: five cases (2010-2021)

CASE SERIES SUMMARY

Nasal planum tumors are rare in cats, with squamous cell carcinoma over-represented. Other skin tumors have been reported in this location and though hemangiosarcoma frequently occurs on the skin of the head, these tumors localized to the nasal planum have not been specifically reported. The objectives of this study were to report the clinical findings and outcomes in cats diagnosed with hemangiosarcoma of the nasal planum. Medical records from four different institutions were reviewed to identify cats with a definitive diagnosis of hemangiosarcoma of the nasal planum. Five cats met the inclusion criteria. One cat was treated with palliative radiation therapy (RT) alone, two cats had lesions removed via an excisional biopsy by the primary care veterinarian and two cats had excisional biopsies performed at a referral institution. All four cats that received surgical treatment were treated with adjuvant strontium-90 therapy. The cat receiving palliative RT alone was lost to follow-up 311 days after treatment. At the time of writing, the survival time for 2/3 cats receiving surgery and strontium-90 was 365 days and 1381 days, respectively. One cat receiving this combination of therapy was lost to follow-up immediately after treatment. One cat developed tumor recurrence and a revision surgery via nasal planectomy and upper lip resection was performed 376 days following the initial surgery. Following revision, palliative RT was pursued. The cat was still alive at the time of writing 618 days after the initial procedure, with no evidence of recurrence.

RELEVANCE AND NOVEL INFORMATION

In this case series, surgery was the primary treatment used, but due to the location, only narrow or incomplete surgical margins were possible. RT (strontium-90 and/or palliative) was utilized to decrease the risk of recurrence.

Primary repair of nonsteroidal anti-inflammatory drug-associated full thickness gastrointestinal ulcers in 11 dogs

OBJECTIVE

To report the outcomes of dogs that underwent primary repair of gastroduodenal perforations associated with the administration of nonsteroidal anti-inflammatory drugs (NSAID). A secondary objective was to identify clinicopathological findings that predisposed dogs to postoperative death.

STUDY DESIGN

Retrospective study.

ANIMALS

Eleven dogs with complete gastric or duodenal perforation related to administration of an NSAID that underwent primary surgical repair.

METHODS

Medical records were reviewed for dogs that presented with peritonitis due to a complete gastroduodenal perforation while receiving NSAIDs between November, 2011 and January, 2021. Data collected included patient characteristics, clinical signs, clinicopathological results, surgical details, and postoperative management and outcome.

RESULTS

All dogs were large breeds (mean weight 42 kg; range 22-75 kg), with a mean age of 7.35 years. Nine dogs from a total of 11 (82 %) received a concurrent corticosteroid and NSAID, or a higher dose/frequency/length of NSAID administration than recommended by the manufacturer. All gastroduodenal perforations were found in the upper gastrointestinal tract. Eight of 11 (73%) dogs survived to discharge. The median postoperative duration of follow up was 444 days (range 2-1460 days). No association was detected between ulcer size or location and mortality.

CONCLUSION

Most dogs who underwent primary repair of complete gastroduodenal ulcers survived. Gastroduodenal perforations were generally due to the administration of higher or longer doses of NSAIDs, or concurrent administration of another NSAID or corticosteroid.

CLINICAL SIGNIFICANCE

Primary closure may be associated with a high success rate in dogs with full thickness gastroduodenal ulcers.

Complications and outcomes associated with laparoscopic-assisted splenectomy in dogs

OBJECTIVE

To report the perioperative characteristics and outcomes of dogs undergoing laparoscopic-assisted splenectomy (LAS).

ANIMALS

136 client-owned dogs.

PROCEDURES

Multicentric retrospective study. Medical records of dogs undergoing LAS for treatment of naturally occurring splenic disease from January 1, 2014, to July 31, 2020, were reviewed. History, signalment, physical examination and preoperative diagnostic test results, procedural information, complications, duration of hospitalization, histopathologic diagnosis, and perioperative outcomes were recorded. Perioperative complications were defined using the Veterinary Cooperative Oncology Group - Common Terminology Criteria for Adverse Events (VCOG-CTCAE v2) guidelines.

RESULTS

LAS was performed for treatment of a splenic mass (124/136 [91%]), immune-mediated disease (7/136 [5%]), splenomegaly (4/136 [3%]), or immune-mediated disease in conjunction with a splenic mass (1/136 [1%]). Median splenic mass size was 1.3 cm3/kg body weight. Conversion to open laparotomy occurred in 5.9% (8/136) of dogs. Complications occurred in 78 dogs, with all being grade 2 or lower. Median surgical time was 47 minutes, and median postoperative hospital stay was 28 hours. All but 1 dog survived to discharge, the exception being postoperative death due to a suspected portal vein thrombus.

CLINICAL RELEVANCE

In the dogs of this report, LAS was associated with low rates of major complications, morbidity, and mortality when performed for a variety of splenic pathologies. Minimally invasive surgeons can consider the LAS technique to perform total splenectomy in dogs without hemoabdomen and with spleens with modest-sized splenic masses up to 55.2 cm3/kg, with minimal rates of complications, morbidity, and mortality.

Veterinary house officer perceptions of dimensions of well-being during postgraduate training

OBJECTIVE

To describe veterinary house officers’ perceptions of dimensions of well-being during postgraduate training and to identify potential areas for targeted intervention.

SAMPLE

303 house officers.

PROCEDURES

A 62-item questionnaire was generated by use of an online platform and sent to house officers at participating institutions in October 2020. Responses were analyzed for trends and associations between selected variables.

RESULTS

239 residents, 45 rotating interns, and 19 specialty interns responded to the survey. The majority of house officers felt that their training program negatively interfered with their exercise habits, diet, and social engagement. House officers reported engaging in exercise significantly less during times of clinical responsibility, averaging 1.6 exercise sessions/wk (SD ± 0.8) on clinical duty and 2.4 exercise sessions/wk (SD ± 0.9) when not on clinical duty (P < 0.001). Ninety-four percent of respondents reported experiencing some degree of anxiety regarding their physical health, and 95% of house officers reported feeling some degree of anxiety regarding their current financial situation. Overall, 47% reported that their work-life balance was unsustainable for > 1 year; there was no association between specialty and sustainability of work-life balance. Most house officers were satisfied with their current training program, level of clinical responsibility, and mentorship.

CLINICAL RELEVANCE

Veterinary house officers demonstrated a poor balance between the demands of postgraduate training and maintenance of personal health. Thoughtful interventions are needed to support the well-being of veterinary house officers.

Outcome with Surgical Treatment of Canine Soft Tissue Sarcoma in the Region of the Ischiatic Tuberosity: A Veterinary Society of Surgical Oncology Retrospective Study

OBJECTIVE

To determine the outcome of dogs with soft tissue sarcoma (STS) within the region of the ischiatic tuberosity (ITSTS) treated surgically.

STUDY DESIGN

Multi-institutional retrospective study ANIMALS: Fifty-two client-owned dogs with histologically confirmed STS in the region of the IT treated with surgical resection between March 1st, 2009, and March 1st, 2021, and a minimum follow-up time of six months.

METHODS

Data collected included signalment, preoperative diagnostics, surgical intent/method, complications, histopathology, margins, outcome, and cause of death. Statistical analyses were performed to determine significant factors in treatment and prognosis of ITSTS.

RESULTS

Fifty-two dogs with histopathologically-confirmed ITSTS included resulting in 24 grade I, 20 grade II, and seven grade III tumors. Overall survival time and disease progression were negatively associated with tumor grade while recurrence was positively associated with grade and incomplete margins. Overall survival time and progression-free survival time was not reached for tumors graded as I or II and was 255 and 268 days respectively for grade III. Median time to recurrence was not reached for tumors excised with complete margins and 398 days for incomplete margins. There was a 25% reported surgical complication rate.

CONCLUSION

Ischiatic tuberosity soft tissue sarcoma was not found to be a unique clinical entity in dogs. Treatment recommendations and prognosis were similar to STS in other locations. The outcome was influenced by histologic grade and margins.

CLINICAL SIGNIFICANCE

Ischiatic tuberosity soft tissue sarcoma of dogs does not behave more aggressively than those in other locations. Surgical complications were common but not life-threatening. Overall prognosis, including survival and disease recurrence, appears to depend on histological grade and surgical margins. This article is protected by copyright. All rights reserved.

The development of ventricular fibrillation as a complication of pericardiectomy in 16 dogs

OBJECTIVE

To describe the clinical characteristics, perioperative protocols, and outcomes in dogs diagnosed with ventricular fibrillation (VF) while undergoing pericardiectomy.

STUDY DESIGN

Retrospective, multi-institutional study.

ANIMALS

Sixteen client-owned dogs.

METHODS

Cases were accrued through a listserve request posted to 3 subspecialty veterinary societies. Dogs were included if they developed VF during a pericardiectomy performed through an open or thoracoscopic approach. Data collected included signalment, history and physical examination, surgical approach, histopathology, treatment, and outcome.

RESULTS

Indications for pericardiectomy included idiopathic chylothorax (n = 7), neoplasia (4), idiopathic pericardial effusion (4), and foreign body granuloma (1). Surgical approaches included thoracoscopy (12), intercostal thoracotomy (3) and median sternotomy (1). Electrosurgical devices were used to complete at least part of the pericardiectomy in 15 of 16 dogs. Ventricular fibrillation appeared to be initiated during electrosurgical use in 8/15 dogs. However, in 5/15 dogs it was not obviously associated with electrosurgical use. In 3/16 dogs the timing of initiation of VF was unclear. In 7/16 dogs, cardiac arrhythmias were noted prior to the development of VF. Fourteen of 16 dogs died from intraoperative VF.

CONCLUSION

In most dogs ventricular fibrillation was a fatal complication of pericardiectomy. Ventricular fibrillation might be associated with the use of electrosurgical devices and cardiac manipulation during pericardiectomy although a causal link could not be established from the data in this study.

CLINICAL SIGNIFICANCE

Surgeons must be aware of the risk of VF during pericardial surgery. Electrosurgery might need to be used judiciously during pericardiectomy, particularly in dogs exhibiting cardiac arrythmias.

Multi-institutional study of long-term outcomes of a ventral versus lateral approach for mandibular and sublingual sialoadenectomy in dogs with a unilateral sialocele: 46 cases (1999–2019)

OBJECTIVE

To compare the long-term outcomes of a ventral versus lateral surgical approach for mandibular and sublingual sialoadenectomy in dogs with a unilateral sialocele.

ANIMALS

46 client-owned dogs.

PROCEDURES

Medical records of dogs that underwent unilateral sialoadenectomy between 1999 and 2019 were retrospectively reviewed, and information was collected regarding signalment, clinical signs, historical treatment, swelling location, diagnostic imaging findings, sialoadenectomy approach, adjunctive treatments, intraoperative complications, hospitalization time, postoperative complications, recurrence, and contralateral sialocele development.

RESULTS

There were no significant differences in incidences of intraoperative complications, recurrence, or postoperative complications between dogs in which a lateral versus ventral approach was used. Clinically important intraoperative complications included iatrogenic tears in the oral mucosa, ligature slippage from the duct end, hemorrhage, and possible lingual nerve transection. Surgical experience was associated with the likelihood that intraoperative complications would develop. Suspected recurrence was reported in 2 of 26 (8%) dogs that underwent a lateral approach and 2 of 12 (17%) dogs that underwent a ventral approach. Hospitalization time was significantly shorter with the lateral approach than with the ventral approach. Postoperative complications had a short-term onset and occurred in 4 of 25 (16%) dogs that underwent a lateral approach and 3 of 12 (25%) dogs that underwent a ventral approach. Age and presence of a pharyngeal sialocele were associated with development of postoperative complications.

CLINICAL RELEVANCE

Long-term outcomes for ventral and lateral approaches to sialoadenectomy were favorable and appeared to be comparable. Further prospective study into potential associations of sialoadenectomy approach, age, and pharyngeal sialoceles on outcome is needed.

Distribution of histopathologic types of primary pulmonary neoplasia in dogs and outcome of affected dogs: 340 cases (2010-2019)

OBJECTIVE

To provide updated information on the distribution of histopathologic types of primary pulmonary neoplasia in dogs and evaluate the effect of postoperative adjuvant chemotherapy in dogs with pulmonary carcinoma.

ANIMALS

340 dogs.

PROCEDURES

Medical records of dogs that underwent lung lobectomy for removal of a primary pulmonary mass were reviewed, and histopathologic type of lesions was determined. The canine lung carcinoma stage classification system was used to determine clinical stage for dogs with pulmonary carcinoma.

RESULTS

Pulmonary carcinoma was the most frequently encountered tumor type (296/340 [87.1%]), followed by sarcoma (26 [7.6%]), adenoma (11 [3.2%]), and pulmonary neuroendocrine tumor (5 [1.5%]); there was also 1 plasmacytoma and 1 carcinosarcoma. Twenty (5.9%) sarcomas were classified as primary pulmonary histiocytic sarcoma. There was a significant difference in median survival time between dogs with pulmonary carcinomas (399 days), dogs with histiocytic sarcomas (300 days), and dogs with neuroendocrine tumors (498 days). When dogs with pulmonary carcinomas were grouped on the basis of clinical stage, there were no significant differences in median survival time between dogs that did and did not receive adjuvant chemotherapy.

CLINICAL RELEVANCE

Results indicated that pulmonary carcinoma is the most common cause of primary pulmonary neoplasia in dogs; however, nonepithelial tumors can occur. Survival times were significantly different between dogs with pulmonary carcinoma, histiocytic sarcoma, and neuroendocrine tumor, emphasizing the importance of recognizing the relative incidence of these various histologic diagnoses. The therapeutic effect of adjuvant chemotherapy in dogs with pulmonary carcinoma remains unclear and warrants further investigation.

Outcome of dogs with bone marrow suppression secondary to Sertoli cell tumour

Sertoli cell tumours are one of the most common canine testicular neoplasia. These tumours are significantly more likely to arise in cryptorchid dogs and are often functional, oestrogen-secreting tumours which can lead to fatal myelotoxicity. The goal of this study was to describe the outcome of dogs with oestrogen-induced bone marrow suppression secondary to Sertoli cell tumours in seven client-owned dogs. Medical records from April 1, 2011 through April 1, 2021 were reviewed to identify dogs that underwent surgical management of a Sertoli cell tumour with documented bone marrow suppression. Overall, 5/7 dogs required transfusion of blood products peri-operatively. Cases 1 and 6 received a transfusion of packed red blood cells (RBC) prior to surgery and case 5 required a transfusion of whole blood. Case 1 also required a transfusion of platelets before surgery. Post-operatively, cases 1 and 2 received packed RBC's and case 6 received two transfusions of whole blood. Case 3 required transfusions of both fresh frozen plasma and platelets post-operatively. All dogs survived to discharge and 6/7 dogs had documented improvement in haematopoietic values. Two dogs remained chronically thrombocytopenic. The median hospital stay was 4 days. One dog died within 4 weeks of surgery from worsening pancytopenia. Survival for greater than 1 year was documented in 4/7 dogs, and one dog was lost to follow-up 4 months post-operatively. One dog remained severely pancytopenic 4 weeks post-operatively and received oral lithium treatment. Improvements in all blood cell lines were observed within the 4 weeks and resolution of pancytopenia within 6 weeks. Historically, the prognosis for dogs with bone marrow suppression secondary to Sertoli cell tumours was guarded to poor. This report documented improved outcomes for dogs that underwent surgery, including one dog that received lithium chloride as treatment for Sertoli cell tumour-induced bone marrow suppression.

Quantitative and Semi-quantitative Methods for Assessing the Degree of Methylene Blue Staining in Sentinel Lymph Nodes in Dogs

Background: To develop a digital algorithm for quantitative assessment of surface methylene blue staining in whole lymph nodes and validate a semi-quantitative visual scoring method for patient-side use.

Methods: Lymph nodes from canine patients with spontaneous tumors undergoing sentinel lymph node mapping were prospectively assessed ex vivo and photographed. Using an open-source computer-based imaging software, an algorithm was developed for quantification of staining based on a signal-to-background ratio. Next, two blinded observers evaluated images and assigned a semi-quantitative visual score based on surface staining (0—no blue stain, 1−1–50% stained, and 2−51–100% stained) and those results were compared to the established quantitative standard.

Results: Forty-three lymph nodes were included. Image analysis successfully quantified blue staining and differentiated from normal lymph node tissue in all cases. Agreement between observers using the Kappa coefficient demonstrated strong agreement (k = 0.8581, p < 0.0001) between semi-quantitative visual scoring and image analysis. There was substantial interobserver and intraobserver agreement for the scoring system (k = 0.7340, p < 0.0001 and k = 0.8983, p < 0.0001, respectively).

Conclusion: A digital algorithm using an open-source software was simple and straightforward to use for quantification of blue staining. The use of a semi-quantitative visual scoring system shows promise for a simple, objective, repeatable assessment of methylene blue staining at the time of surgery. This study demonstrates reliable and repeatable methods for blue staining quantification thereby providing a novel and objective reporting mechanism in scientific research involving sentinel lymph node mapping.

Evaluating the Feasibility and Efficacy of a Dual-Modality Nanoparticle Contrast Agent (Nanotrast-CF800) for Image-Guided Sentinel Lymph Node Mapping in the Oral Cavity of Healthy Dogs

A combination of pre and intraoperative sentinel lymph node (SLN) mapping techniques have been suggested to optimize SLN detection. A novel liposomal nanoparticle, Nanotrast-CF800 (CF800), utilizes computed tomography lymphography (CTL) and near infrared fluorescence imaging (NIRF) for image-guided surgery and SLN mapping. This novel tracer agent has not been evaluated in companion animals. The objective of this study was to evaluate the feasibility and efficacy of CF800 for SLN mapping in the oral cavity of healthy dogs and to report any local adverse effects. Six healthy adult purpose-bred research dogs randomly received either 1 mL (group 1) or 2 mL (group 2) of CF800 injected into the submucosa at the level of the right canine maxillary tooth. CTL and percutaneous NIRF were performed at 1, 3, and 10 min, then 1, 2, 4, 7, and 10 days post-injection (p.i). Overall, both CTL and NIRF identified SLNs in all dogs. The overall peak mean contrast enhancement of the SLNs was 73.98 HU (range 63.45-86.27 HU) at 2 days p.i. Peak fluorescence of the SLN occurred at 1 day p.i. The agent was retained within the SLN for at least 7 days for CTL and 4 days for percutaneous NIRF. No adverse effects were observed. Local administration of CF800 was simple and feasible for the detection of SLNs using CTL+NIRF in the head and neck of healthy dogs and was not associated with significant local adverse events.

Angularis oris axial pattern flap as a reliable and versatile option for rostral facial reconstruction in cats

OBJECTIVE

To evaluate outcomes associated with the use of an angularis oris axial pattern flap (AOAPF) for rostral facial reconstruction in cats.

ANIMALS

Nine adult client-owned cats.

STUDY DESIGN

Short case series.

METHODS

Ten AOAPF were performed in nine cats after resection of a tumor. Wounds were located at the nose, infraorbital, supraorbital, frontal, eye, and ear canal region. Orbital exenteration (n = 3), pinnectomy (n = 2), nasal planum resection, total ear canal ablation (n = 2), and partial eyelid reconstruction (n = 3) were performed.

RESULTS

Short-term postoperative complications included flap edema (n = 10), suture dehiscence (n = 3), and distal tip necrosis (n = 3). All wounds resulting from minor complications healed by second intention in 5-15 days. Long-term complications included epiphora (n = 2), frequent grooming around the eyes (n = 2), and enucleation due to corneal ulcer secondary to impaired postoperative eyelid function (n = 1). Tumor recurrence occurred in 3 cases.

CONCLUSION

The AOAPF was a versatile and reliable option for rostral facial reconstruction in cats with acceptable long-term outcomes.

International Guidelines for Veterinary Tumor Pathology: A Call to Action

Standardization of tumor assessment lays the foundation for validation of grading systems, permits reproducibility of oncologic studies among investigators, and increases confidence in the significance of study results. Currently, there is minimal methodological standardization for assessing tumors in veterinary medicine, with few attempts to validate published protocols and grading schemes. The current article attempts to address these shortcomings by providing standard guidelines for tumor assessment parameters and protocols for evaluating specific tumor types. More detailed information is available in the Supplemental Files, the intention of which is 2-fold: publication as part of this commentary, but more importantly, these will be available as "living documents" on a website (www.vetcancerprotocols.org), which will be updated as new information is presented in the peer-reviewed literature. Our hope is that veterinary pathologists will agree that this initiative is needed, and will contribute to and utilize this information for routine diagnostic work and oncologic studies. Journal editors and reviewers can utilize checklists to ensure publications include sufficient detail and standardized methods of tumor assessment. To maintain the relevance of the guidelines and protocols, it is critical that the information is periodically updated and revised as new studies are published and validated with the intent of providing a repository of this information. Our hope is that this initiative (a continuation of efforts published in this journal in 2011) will facilitate collaboration and reproducibility between pathologists and institutions, increase case numbers, and strengthen clinical research findings, thus ensuring continued progress in veterinary oncologic pathology and improving patient care.

A retrospective analysis of 11 dogs with surface osteosarcoma

While the majority of canine osteosarcomas (OSA) arise from the medullary cavity, a subset arises from the surface of bone. In humans, surface OSA often has a more indolent disease course with better outcomes than medullary OSA. The aim of this retrospective case series was to evaluate the clinical outcome and potential prognostic factors of dogs with surface OSA. Medical records from 11 dogs previously diagnosed with surface OSA were included. Histopathology of cases was evaluated during case review by two veterinary anatomic pathologists. Median progression free interval (PFI) and overall median survival time (OST) were estimated using Kaplan-Meier methods. Intergroup comparisons were performed using log-rank tests. Six dogs were diagnosed with periosteal OSA, 4 dogs with parosteal OSA, and one dog with an unclassified surface OSA. Two dogs were found to have metastatic disease at the time of diagnosis and four developed metastatic lesions after treatment. The median PFI and median OST for all dogs with surface OSA was 425 and 555 days, respectively. The 6 dogs diagnosed with periosteal OSA had a median PFI of 461 days and median OST of 555 days, while the 4 dogs with parosteal OSA had a PFI of 350 days and the OST could not be calculated. Multiple prognostic factors (surgery, systemic adjunctive therapy, elevated alkaline phosphatase at diagnosis, appendicular vs axial location, mitotic count, and tumour grade) were evaluated and none were prognostic for PFI or OST. Dogs with surface OSA appear to have prolonged PFI and OST, consistent with humans with surface OSA.

The use of near infrared fluorescence imaging with indocyanine green for vascular visualization in caudal auricular flaps in two cats

OBJECTIVES

To describe the use of near infrared fluorescence (NIRF) imaging with indocyanine green (ICG) for vascular visualization in two caudal auricular axial pattern flaps (APF).

ANIMALS

Two client-owned cats with upper eyelid masses.

STUDY DESIGN

Clinical case report.

METHODS

Wide surgical excision with enucleation was performed by using a caudal auricular APF for closure. Flap margins and perforating artery location were approximated with anatomical landmarks. The caudal auricular artery origin was then visualized percutaneously by using an exoscope with NIRF camera and light source after a single 2.5-mg dose of IV ICG. Margins were adjusted as required. The flaps were routinely elevated with continued intraoperative visualization of the artery and rotated to complete closure.

RESULTS

After IV ICG administration, fluorescence was initially visualized after 15 to 18 seconds and remained visible for up to 26 minutes. The achieved visualization led to flap margin adjustments in cat 1. Both cats recovered with minimal flap congestion, excellent hair regrowth, and no long-term complications (>186 days). Cat 1 experienced 100% flap survival. Cat 2 experienced 10% partial thickness flap necrosis, but revision was not required, and the flap was healed at recheck 85 days postoperatively.

CONCLUSION

The use of ICG for APF vessel visualization prior to and during flap elevation resulted in transcutaneous visualization of the perforating vessel and improved awareness of vessel location intraoperatively. These two cats experienced excellent flap survival without major complications. This report highlights the potential benefits of ICG NIRF in APF for animals undergoing reconstructive surgery.

Determining agreement between preoperative computed tomography lymphography and indocyanine green near infrared fluorescence intraoperative imaging for sentinel lymph node mapping in dogs with oral tumours

Lymphatic drainage from the head and neck is variable with significant crossover, therefore sentinel lymph node (SLN) mapping can help ensure the appropriate lymph node(s) are sampled. To improve sensitivity, SLN mapping utilizing multiple modalities and a combination of preoperative computed tomography lymphography (CTL) and intraoperative near infrared fluorescence imaging (NIRF) with indocyanine green (ICG) +/- methylene blue (MB) dye has been suggested. The aim of this study was to describe a method for intraoperative ICG lymphography and determine agreement for SLN detection using preoperative CTL and intraoperative ICG NIRF + MB lymphography (IOL) in dogs with oral tumours. Fourteen client-owned dogs were included. All dogs had preoperative CTL with iodinated contrast and intraoperative IOL with an exoscope. Lymph nodes with CTL contrast-enhancement, blue staining or fluorescence were considered sentinel. The overall SLN identification rate was 100% when CTL and IOL were combined. A total of 57 SLNs were identified. Indocyanine green NIRF identified a greater proportion of SLNs (91%; 52/57) compared with MB (50.8%; 29/57) and CTL (42.1%; 24/57). Eighteen SLNs were identified by all three modalities with a fair level of agreement using Fleiss kappa. These findings suggest a combination of preoperative CTL with intraoperative SLN mapping techniques may greatly improve the ability to accurately detect the SLN in dogs with oral tumours.

Clinical features and outcome of functional thyroid tumours in 70 dogs

OBJECTIVE

To describe the clinical features and outcome of functional thyroid tumours in dogs.

MATERIALS AND METHODS

Retrospective multi-institutional study of 70 dogs diagnosed with thyroid mass and concurrent hyperthyroidism. Clinical data regarding presentation, treatment, outcome and functional thyroid status were retrieved.

RESULTS

Overall median survival of dogs with functional thyroid tumours was 35.1 months and 1- and 3-year survival rates were 83 and 49%, respectively. Median survival time was 72.6 months for dogs treated with surgical excision and 15.7 months for dogs that did not receive surgery. Of the 50 dogs treated by surgery and for which thyroid status was known following treatment, 64% developed hypothyroidism after surgery. Histopathologically confirmed metastasis was identified in 3% of dogs.

CLINICAL SIGNIFICANCE

Dogs with functional thyroid tumours may survive a long time after surgical excision, although post-operative hypothyroidism is common.

Comparison of lateral surgical margins of up to two centimeters with margins of three centimeters for achieving tumor-free histologic margins following excision of grade I or II cutaneous mast cell tumors in dogs

OBJECTIVE

To determine whether conservative lateral surgical margins (equal to tumor diameter for tumors < 2 cm in diameter or 2 cm for larger tumors) were noninferior to wide (3-cm) lateral surgical margins for achieving tumor-free histologic margins following excision of grade I and II cutaneous mast cell tumors (MCTs) in dogs.

ANIMALS

83 grade I and II MCTs excised with a deep surgical fascial margin and requisite lateral surgical margins from 68 dogs from 2007 to 2017. Tumors representing scar revision or local recurrence were excluded.

PROCEDURES

A pathology department database was searched to identify qualifying MCTs, and medical records were cross-referenced to obtain data regarding patients and tumors. Outcome (complete vs incomplete excision as histologically determined) was compared between conservative- and wide-margin groups. A noninferiority margin of ≥ 0.9 was used for the risk ratio (probability of complete excision for the conservative- vs wide-margin group), implying that noninferiority would be established if the data indicated that the true risk of complete excision with the conservative-margin approach was at worst 90% of that for the wide-margin approach.

RESULTS

The proportion of excised MCTs with tumor-free histologic margins was similar between the conservative- (43/46 [93%]) and wide- (34/37 [92%]) margin groups. There were no differences in tumor diameter or location between treatment groups. The risk ratio (1.02; 95% confidence interval, 0.89 to 1.19) met the criterion for noninferiority.

CONCLUSIONS AND CLINICAL RELEVANCE

The conservative-margin approach appeared to be noninferior to the wide-margin approach for achieving tumor-free histologic margins in the dogs of this study, and its use could potentially reduce the risk of postoperative complications. (J Am Vet Med Assoc 2020;256:567-572.

Effect of timing of bisphosphonate administration on canine osteosarcoma cells undergoing radiation therapy

The effects of radiation therapy may be potentiated by combining radiation therapy with secondary therapies. Clinically, radiation therapy has been combined with bisphosphonates for treatment of canine appendicular osteosarcoma for years. The objective of this study was to determine if the timing of administration of bisphosphonates in relation to radiation therapy alters clonogenic survival or cell viability of canine osteosarcoma cells in vitro. Canine osteosarcoma cells were treated before administration of radiation, concurrent with radiation, or after radiation. Reduction in clonogenic survival was identified when bisphosphonates were administered post-radiation compared with pre-radiation. No significant differences were identified for cell viability at any time points. Further investigation of the cellular effects of bisphosphonates on canine osteosarcoma cells is warranted. Consideration may be given to administering bisphosphonates 24 h after radiation to reduce replication of canine osteosarcoma cells and possibly prolong the analgesic effects of both treatments.

Histologic evaluation of mandibular and medial retropharyngeal lymph nodes during staging of oral malignant melanoma and squamous cell carcinoma in dogs

OBJECTIVE

To assess histologic evaluation of mandibular lymph nodes (MLNs) and medial retropharyngeal lymph nodes (MRLNs) for metastatic disease during tumor staging for dogs with oral malignant melanoma (OMM) and oral squamous cell carcinoma (OSCC).

DESIGN

Retrospective multi-institutional study.

ANIMALS

27 dogs with OMM and 21 dogs with OSCC.

PROCEDURES

Medical record databases of 8 institutions were searched to identify dogs with OMM or OSCC that underwent unilateral or bilateral extirpation of the MLNs and MRLNs during the same procedure between January 2004 and April 2016. Information extracted from the records included signalment, primary mass location and size, diagnostic imaging results, histologic results for the primary tumor and all lymph nodes evaluated, and whether distant metastasis developed.

RESULTS

Prevalence of lymph node metastasis did not differ significantly between dogs with OMM (10/27 [37%]) and dogs with OSCC (6/21 [29%]). Distant metastasis was identified in 11 (41%) dogs with OMM and was suspected in 1 dog with OSCC. The MRLN was affected in 13 of 16 dogs with lymph node metastasis, and 3 of those dogs had metastasis to the MRLN without concurrent metastasis to an MLN. Metastasis was identified in lymph nodes contralateral to the primary tumor in 4 of 17 dogs that underwent contralateral lymph node removal.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated histologic evaluation of only 1 MLN was insufficient to definitively rule out lymph node metastasis in dogs with OMM or OSCC; therefore, bilateral lymphadenectomy of the MLN and MRLN lymphocentra is recommended for such dogs.

Comparison of complications and outcome following unilateral, staged bilateral, and single-stage bilateral ventral bulla osteotomy in cats

OBJECTIVE

To compare complications and outcome following unilateral, staged bilateral, and single-stage bilateral ventral bulla osteotomy (VBO) in cats.

ANIMALS

282 client-owned cats treated by VBO at 25 veterinary referral and academic hospitals from 2005 through 2016.

PROCEDURES

Medical records of cats were reviewed to collect information on signalment, clinical signs, diagnostic test results, surgical and postoperative management details, complications (anesthetic, surgical, and postoperative), and outcome. Associations were evaluated among selected variables.

RESULTS

Unilateral, staged bilateral, and single-stage bilateral VBO was performed in 211, 7, and 64 cats, respectively, representing 289 separate procedures. Eighteen (9%), 2 (29%), and 30 (47%) of these cats, respectively, had postoperative respiratory complications. Cats treated with single-stage bilateral VBO were significantly more likely to have severe respiratory complications and surgery-related death than cats treated with other VBO procedures. Overall, 68.2% (n = 197) of the 289 procedures were associated with Horner syndrome (19.4% permanently), 30.1% (87) with head tilt (22.1% permanently), 13.5% (39) with facial nerve paralysis (8.0% permanently), and 6.2% (18) with local disease recurrence. Cats with (vs without) Horner syndrome, head tilt, and facial nerve paralysis before VBO had 2.6, 3.3, and 5.6 times the odds, respectively, of having these conditions permanently.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings suggested that staged bilateral VBO should be recommended over single-stage bilateral VBO for cats with bilateral middle ear disease. Cats with Horner syndrome, head tilt, and facial nerve paralysis before surgery were more likely to have these conditions permanently following surgery than were cats without these conditions.

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.

Schedule feasibility and workflow for additive manufacturing of titanium plates for ranioplasty in canine skull tumors

Background

Additive manufacturing has allowed for the creation of a patient-specific custom solution that can resolve many of the limitations previously reported for canine cranioplasty. The purpose of this pilot study was to determine the schedule feasibility and workflow in manufacturing patient-specific titanium implants for canines undergoing cranioplasty immediately following craniectomy.

Results

Computed tomography scans from patients with tumors of the skull were considered and 3 cases were selected. Images were imported into a DICOM image processing software and tumor margins were determined based on agreement between a board-certified veterinary radiologist and veterinary surgical oncologist. Virtual surgical planning was performed and a bone safety margin was selected. A defect was created to simulate the planned intraoperative defect. Stereolithography format files of the skulls were then imported into a plate design software. In collaboration with a medical solution centre, a custom titanium plate was designed with the input of an applications engineer and veterinary surgery oncologist. Plates were printed in titanium and post-processed at the solution centre. Total planning time was approximately 2 h with a manufacturing time of 2 weeks.

Conclusions

Based on the findings of this study, with access to an advanced 3D metal printing medical solution centre that can provide advanced software and printing, patient-specific additive manufactured titanium implants can be planned, created, processed, shipped and sterilized for patient use within a 3-week turnaround.

A systematic review of criteria used to report complications in soft tissue and oncologic surgical clinical research studies in dogs and cats

Objective

To evaluate reporting of surgical complications and other adverse events in clinical research articles describing soft tissue and oncologic surgery in dogs and cats.

Study design

Systematic literature review.

Sample

English‐language articles describing soft tissue and oncologic surgeries in client‐owned dogs and cats published in peer‐reviewed journals from 2013 to 2016.

Methods

CAB, AGRICOLA, and MEDLINE databases were searched for eligible articles. Article characteristics relevant to complications were abstracted and summarized, including reported events, definitions, criteria used to classify events according to severity and time frame, and relevant citations.

Results

One hundred fifty‐one articles involving 10 522 animals were included. Canine retrospective case series of dogs predominated. Ninety‐two percent of articles mentioned complications in study results, but only 7.3% defined the term complication. Articles commonly described complications according to time frame and severity, but terminology and classification criteria were highly variable, conflicting between studies, or not provided. Most (58%) reported complications could have been graded with a published veterinary adverse event classification scheme, although common intraoperative complications were notable exceptions.

Conclusion

Definitions and criteria used to classify and report soft tissue and oncologic surgical complications are often absent, incomplete, or contradictory among studies.

Clinical significance

Lack of consistent terminology contributes to inadequate communication of important information about surgical complications. Standardization of terminology and consistency in severity scoring will improve comparative evaluation of clinical research results.

Efficiency of ultrasound-guided aspiration of medial retropharyngeal lymph node in dogs

The purpose of this retrospective cross-sectional study was to assess the diagnostic yield of ultrasound-guided aspiration of the medial retropharyngeal lymph node (MRPLN) and to report factors on computed tomography (CT) evaluation that are predictive of obtaining a diagnostic sample. A secondary objective was to report CT size reference ranges for cytologically confirmed normal MRPLNs in dogs. Medical records and CT images of 69 dogs were retrospectively reviewed. The diagnostic yield of ultrasound-guided aspiration on MRPLNs was 47.5%. Six lymph nodes were positive for metastasis with various cancers. Only rostral height was predictive of the diagnostic yield. The Pearson correlation coefficient and Spearman's Rho tests suggested that the age of the dog has significant negative linear correlation with the size of MRPLNs while the weight has positive correlation. Overall, ultrasound-guided aspiration of MRPLN has low diagnostic yield in normal size lymph nodes. Prior case selection based on CT evaluation may increase the probability of diagnostic samples.

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.

Evaluation of effects of radiation therapy combined with either pamidronate or zoledronate on canine osteosarcoma cells

Canine osteosarcoma is a devastating disease with an overall poor prognosis. Radiation therapy and bisphosphonates are currently used in combination for palliative treatment, despite a paucity of literature that investigates their combined use. The objectives of this study were to assess the in vitro effects of radiation therapy and bisphosphonates on canine osteosarcoma cells when used in combination. Canine osteosarcoma cell lines D17 and Dharma were treated with radiation and pamidronate or zoledronate, both alone and in combination. The effects of these treatments were assessed using clonogenic survival and cell viability assays. Dose-dependent decreases in clonogenic survival and cell viability were observed for both radiation and bisphosphonate treatment. Combination index analysis revealed antagonistic interactions when radiation and bisphosphonates were used in combination at specific doses for both D17 and Dharma osteosarcoma cells. Further investigation of the combined effects of radiation and bisphosphonates for the palliative treatment of canine osteosarcoma is warranted.

Outcome of prolonged acute vena cava occlusion after iatrogenic transection and repair in a dog

A 12-year-old castrated male Airedale terrier dog was diagnosed with a hepatocellular carcinoma in the right medial liver lobe. During tumor resection, inadvertent stapling and transection of the caudal vena cava occurred. Complete caval occlusion was required for 18 minutes and primary anastomosis was completed. The dog received 2 blood transfusions and developed mild pelvic limb edema after surgery. Computed tomography evaluation 9 months after surgery showed collateral circulation and suspected stricture of the vena cava with an absence of clinical effect. The dog remained alive and asymptomatic more than 1 year after surgery.

Proximal duodenoileal anastomosis for treatment of small intestinal obstruction and volvulus in a green iguana (Iguana iguana)

CASE DESCRIPTION A 13-year-old female green iguana (Iguana iguana) was examined because of a 6-day history of vomiting, anorexia, and lethargy and a 4-day history of decreased fecal and urate output. CLINICAL FINDINGS Physical examination revealed a distended abdomen, signs of depression, pallor, tachycardia, harsh lung sounds, and vomiting. Abdominal radiographs revealed gas distention of the stomach and small intestine with fluid lines evident on the lateral view. Plasma biochemical analysis indicated hypochloremic metabolic alkalosis, hyperglycemia, and hyperuricemia. TREATMENT AND OUTCOME Exploratory laparotomy confirmed a diagnosis of small intestinal entrapment and 170° volvulus involving approximately 80% (20 to 30 cm) of the small intestine. The portion of the small intestine extending from the middle portion of the duodenum to the caudal extent of the ileum was resected, and end-to-end anastomosis of the remaining small intestine was performed. The iguana recovered without apparent complications and was reportedly doing well 1 year after surgery. CLINICAL RELEVANCE Findings suggested that iguanas, as hindgut fermenters, may tolerate > 70% resection of the small intestine with a good outcome and no clinical evidence of residual gastrointestinal dysfunction.

Pubectomy and stereotactic radiotherapy for the treatment of a non-resectable sacral osteosarcoma causing pelvic canal obstruction in a dog

A pubectomy was carried out to relieve obstruction of the pelvic canal in a 6-year-old dog diagnosed with sacral osteosarcoma. Two days after surgery, the dog was ambulatory with normal urination and defecation. Pubectomy is a viable option to relieve clinical signs in patients with pelvic canal obstruction due to a non-resectable tumor.

Ischiectomy With Limb Preservation for a Dog With Ischial Chondrosarcoma: Case Report and Surgical Technique

OBJECTIVE

To describe the surgical technique for ischiectomy in the dog and to report the procedure in a case.

STUDY DESIGN

Case report.

ANIMAL

An 11-year-old spayed female mixed breed dog with chondrosarcoma of the ischium.

METHODS

The dog presented for hindlimb lameness and evaluation after a radiographic finding of a lytic lesion confined to the left ischium. Following staging and confirmation of stage 1 disease, an ischiectomy with preservation of the hindlimb was performed.

RESULTS

The dog recovered from surgery and was initially moderately lame on the hindlimb. Over time, the dog regained satisfactory hindlimb use and was alive >500 days postoperative with no evidence of local recurrence or metastatic disease.

CONCLUSIONS

Ischiectomy with hindlimb preservation is a technically straight-forward procedure and in this case, resulted in good hindlimb function postoperatively. The procedure should be considered for the treatment of dogs with bone tumors confined to the ischium.

The impact of pamidronate and chemotherapy on survival times in dogs with appendicular primary bone tumors treated with palliative radiation therapy

OBJECTIVE

To assess survival times in dogs that received palliative radiation therapy (RT) alone, and in combination with chemotherapy, pamidronate, or both for primary appendicular bone tumors and determine whether the addition of these adjunctive therapies affects survival.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 50) with primary appendicular bone tumors.

METHODS

Dogs were divided into the following treatment groups: RT alone, RT + chemotherapy, RT+ pamidronate, and RT+ chemotherapy + pamidronate. Dogs were considered for analysis if they had a known euthanasia date or follow-up data were available for at least 120 days from the time of diagnosis. Survival time was defined as the time from admission to euthanasia. Cox proportional hazard models and Kaplan-Meier survival functions were used. A P value of less than .05 was considered significant.

RESULTS

Fifty dogs were considered for survival analysis. Median survival times (MSTs) were longest for dogs receiving RT and chemotherapy (307 days; 95% CI: 279, 831) and shortest in dogs receiving RT and pamidronate (69 days; 95% CI: 47, 112 days). The difference in MST between dogs who received pamidronate and those who did not in this population was statistically significant in a univariate (P = .039) and multivariate analysis (P = .0015). The addition of chemotherapy into any protocol improved survival (P < .001).

CONCLUSIONS

Chemotherapy should be recommended in addition to a palliative RT protocol to improve survival of dogs with primary appendicular bone tumors. When combined with RT ± chemotherapy, pamidronate decreased MST and should not be included in a standard protocol.

Congenital duplex gallbladder and biliary mucocele associated with partial hepatic cholestasis and cholelithiasis in a cat

A 6-year-old neutered male domestic shorthair cat was presented for acute onset of vomiting. Exploratory laparotomy identified a duplex gallbladder and left cholecystectomy was performed. Histopathology confirmed biliary mucocele and hepatic cholestasis. While rare, biliary mucoceles should be considered as a differential diagnosis for feline extrahepatic bile duct obstruction.