Diagnostic accuracy of contrast-enhanced computed tomography for assessment of mandibular and medial retropharyngeal lymph node metastasis in dogs with oral and nasal cancer.

The diagnostic accuracy of contrast-enhanced CT for detection of cervical lymph node metastasis in dogs is unknown. The purpose of this retrospective, observational, diagnostic accuracy study was to assess the efficacy of CT for detection of mandibular and medial retropharyngeal lymph node metastasis in dogs. Histopathology of dogs with cancer of the head, CT and bilateral mandibular and medial retropharyngeal lymphadenectomy was reviewed. A single radiologist measured lymph nodes to derive short axis width and long-short axis ratios. Two blinded radiologists separately assessed lymph node margins, attenuation and contrast enhancement and each provided a final subjective interpretation of each node site as benign or neoplastic. Where radiologists' opinions differed, a consensus was reached. Sensitivity, specificity and accuracy were calculated for mandibular and medial retropharyngeal sites. Agreement between radiologists was assessed. Fisher's exact test and the Kruskal-Wallis H-test were used to assess associations between variables. Forty-one primary tumours were recorded in 40 dogs. Metastasis to mandibular or retropharyngeal lymph nodes occurred in 16 out of 40 dogs (43/160 nodes). Agreement between radiologists was almost perfect for margination, attenuation and enhancement, strong for interpretation of mandibular lymph node metastasis, and weak for interpretation of medial retropharyngeal lymph node metastasis. Sensitivity of CT was 12.5% and 10.5%, specificity was 91.1% and 96.7%, and accuracy was 67.5% and 76.3% for mandibular and medial retropharyngeal lymph nodes respectively. No individual CT findings were predictive of nodal metastasis. Given the low sensitivity of CT, this modality cannot be relied upon alone for assessment of cervical lymph node metastasis in dogs.

Compartmental resection of peripheral nerve tumours with limb preservation in 16 dogs (1995-2011).

Peripheral nerve tumours (PNTs) affecting the limbs may lead to chronic pain, lameness and/or monoparesis that is refractory to medical treatment. The most common radical therapy for PNTs has been surgical excision with limb amputation. However, compartmental resection with preservation of the limb has been performed by the authors with favourable clinical results and therefore this bi-institutional retrospective study was undertaken to assess limb function, survival and recurrence. Sixteen dogs that had been diagnosed with PNTs between 1995 and 2011 met the inclusion criteria for this study. In the majority of the cases, good to excellent limb function was achieved. The overall median survival time (MST) was 1303days (42.8 months; range, 14 days-4639 days, [0.5-152.4 months]), with two dogs still alive at time of evaluation. Non-infiltrated margins were the best prognostic indicator; dogs with non-infiltrated margins had a MST of 2227days (P<0.001) compared to dogs with infiltrated margins (MST of 487 days). The 1-year calculated survival rate was 68.8% and the 2- and 3-year calculated survival rates were 62.5%. Surgical treatment with tumour removal and limb spare for proximal and distal PNTs can be successful. Compartmental excision can lead to good limb function, producing survival comparable to limb amputation, and should therefore be considered as an alternative to limb amputation in canine PNTs.

Evaluation of Weight Change During Carboplatin Therapy in Dogs With Appendicular Osteosarcoma.

BACKGROUND: The prevalence of cancer cachexia in veterinary medicine has not been studied widely, and as of yet, no definitive diagnostic criteria effectively assess this syndrome in veterinary patients. OBJECTIVES: (1) To determine the patterns of weight change in dogs with appendicular osteosarcoma treated with amputation and single-agent carboplatin during the course of adjuvant chemotherapy; and (2) to determine whether postoperative weight change is a negative prognostic indicator for survival time in dogs with osteosarcoma. ANIMALS: Eighty-eight dogs diagnosed with appendicular osteosarcoma. Animals were accrued from 3 veterinary teaching hospitals. METHODS: Retrospective, multi-institutional study. Dogs diagnosed with appendicular osteosarcoma and treated with limb amputation followed by a minimum of 4 doses of single-agent carboplatin were included. Data analyzed in each patient included signalment, tumor site, preoperative serum alkaline phosphatase activity (ALP), and body weight (kg) at each carboplatin treatment. RESULTS: A slight increase in weight occurred over the course of chemotherapy, but this change was not statistically significant. Weight change did not have a significant effect on survival. Institution, patient sex, and serum ALP activity did not have a significant effect on survival. CONCLUSIONS AND CLINICAL IMPORTANCE: Weight change was not a prognostic factor in these dogs, and weight loss alone may not be a suitable method of determining cancer cachexia in dogs with appendicular osteosarcoma.

Bilateral removal of the mandibular and medial retropharyngeal lymph nodes through a single ventral midline incision for staging of head and neck cancers in dogs: a description of surgical technique.

Currently, there is no standard protocol for removal of regional lymph nodes for the staging of head and neck cancers in dogs. Palpation and fine needle aspiration of mandibular lymph nodes are most commonly performed for staging of head and neck cancers. Although cytology is commonly performed for staging of head and neck, cancers histopathology is required for definitive lymph node staging. When regional lymph node biopsy is performed, mandibular lymph nodes are most commonly sampled due to their accessibility. The medial retropharyngeal lymph nodes may be the most relevant draining lymph node of the head and neck, but they are not routinely sampled due to their anatomic location medial to the salivary glands. The technique described here will allow for a standardized surgical approach for the efficient removal of both mandibular and medial retropharyngeal lymph nodes for staging of head and neck tumours via a single ventral midline approach.

The impact of the increasing burden of trauma in Malawi on orthopedic trauma service priorities at Kamuzu Central Hospital.

Background and purpose - The burden of road traffic injuries globally is rising rapidly, and has a huge effect on health systems and development in low- and middle-income countries. Malawi is a small low-income country in southeastern Africa with a population of 16.7 million and a gross national income per capita of only 250 USD. The impact of the rising burden of trauma is very apparent to healthcare workers on the ground, but there are very few data showing this development. Patients and methods - The annual number of femoral fracture patients admitted to Kamuzu Central Hospital (KCH) in the Capital of Malawi, Lilongwe, from 2009 to 2014 was retrieved from the KCH trauma database. Linear regression curve estimation was used to project the growth in the burden of femoral fractures and the number of operations performed for femoral fractures over the same time period. Results - 992 patients with femoral fractures (26% of all admissions for fractures) presented at KCH from 2009 through 2014. In this period, there was a 132% increase in the annual number of femoral fractures admitted to KCH. In the same time period, the total number of operations more than doubled, but there was no increase in the number of operations performed for femoral fractures. Overall, there was a 7% mortality rate for patients with femoral fractures. Interpretation - The burden of femoral fractures in Malawi is rising rapidly, and the surgical resources available cannot keep up with this development. Limited funds for orthopedic trauma care in Malawi should be invested in central training hospitals, to develop a sustainable number of orthopedic surgeons and improve current infrastructure and equipment. The centralization of orthopedic surgical care delivery at the central training hospitals will lead to better access to surgical care and early return of patients to local district hospitals for rehabilitation, thus increasing surgical throughput and efficiency in a more cost-effective manner, with the goal of expanding the future orthopedic surgical workforce to meet the national need.

Outcome After Pneumonectomy in 17 Dogs and 10 Cats: A Veterinary Society of Surgical Oncology Case Series.

OBJECTIVE: To report the signalment, presenting clinical signs, surgical complications, histologic diagnosis, postoperative complications, and outcome of dogs and cats undergoing pneumonectomy. STUDY DESIGN: Retrospective case series; multicenter study. ANIMALS: Client-owned dogs (n=17) and cats (n=10). METHODS: Signalment, clinical signs, side affected, surgical data, preoperative diagnostic tests (including complete blood count, serum biochemistry, cytologic diagnosis, chest radiographs, and computed tomography), histologic diagnosis, surgical complications, adjunctive therapy, and date and cause of death were collected from records of dogs and cats that underwent pneumonectomy. Survival estimates and complication were assessed. RESULTS: Seventeen animals had a left-sided pneumonectomy performed (12 dogs, 5 cats) and 10 animals had a right-sided pneumonectomy (5 dogs, 5 cats). Fourteen animals were diagnosed with neoplasia (52%). The overall incidence of complications for dogs and cats were 76 and 80%, respectively, with major complications in 41 and 50%, respectively. Respiratory complications (persistent pleural effusion, oxygen dependence, persistent increased respiratory rate, or coughing) were the most frequent complications. No animals died or were euthanatized intraoperative or within the first 24 hours postoperative. One dog (6%) and 2 cats (20%) died, or were euthanatized in the first 2 weeks postoperative. CONCLUSION: Based on this case series, right and left pneumonectomy can be performed with low perioperative mortality in dogs and cats, with some animals experiencing prolonged survival.

Receptor Tyrosine Kinase Expression Profiles in Canine Cutaneous and Subcutaneous Mast Cell Tumors.

The receptor tyrosine kinase (RTK) KIT is a major focus of current research into canine mast cell tumors (MCTs). Little is known about the role of other RTKs, such as vascular endothelial growth factor receptors (VEGFRs) and platelet-derived growth factor receptors (PDGFRs). These RTKs are dysregulated in many human and animal cancers and are key regulators of tumor angiogenesis. The aims of this study were to assess the expression and activation (phosphorylation) status of KIT, VEGFR2, and PDGFR (α and ß) in canine MCTs and to examine associations with various clinical outcomes. c-KITmutational status and KIT cellular localization pattern were also evaluated for these tumors. Twenty-seven MCTs, consisting of 5 subcutaneous and 22 cutaneous tumors, from 25 dogs were evaluated. MCT biopsies, cultured mast cells, and skin from the surgical margin were analyzed through Western blotting. MCT biopsies were also used for KIT immunohistochemical labeling and polymerase chain reaction for c-KITmutational analysis. MCT had heterogeneous expression profiles for all 3 RTKs, which varied in intensity and activation status. Statistical analyses showed phosphorylated KIT, VEGFR2, and KIT cellular localization to be predictive of decreased survival time, disease-free interval, and increased metastatic rate. Expression of VEGFR2 and KIT diffuse cytoplasmic labeling were also significantly associated with increased rate of local recurrence. The results of the study show that phosphorylated KIT, KIT, VEGFR2, and PDGFRß, in addition to KIT localization, may be valuable prognostic determinants in MCTs and should be further studied to improve diagnostic and therapeutic modalities.

Outcome of definitive fractionated radiation followed by exenteration of the nasal cavity in dogs with sinonasal neoplasia: 16 cases.

Local control is a major challenge in treating canine nasal tumours. Surgical cytoreduction prior to radiation therapy has not been shown to offer a survival advantage. Only one study has previously evaluated the outcome when surgery is performed after radiation, which demonstrated an improved survival time compared with radiation alone. The purpose of this study was to investigate the outcome of surgery after definitive radiation on survival times in dogs with sinonasal tumours. Medical records were retrospectively reviewed for dogs with nasal tumours that received definitive radiation followed by surgery. Information obtained from medical record review included signalment, diagnosis, treatment and outcome. The median survival time was 457 days. No long-term side effects were observed. These findings suggest that exenteration of the nasal cavity following definitive radiation for treatment of dogs with nasal tumours is well-tolerated and provides a similar survival duration to previous reports of radiation alone.

Comparison of concurrent imaging modalities for staging of dogs with appendicular primary bone tumours.

This study assessed the use of whole body computed tomography (CT) for the evaluation of metastasis in dogs with primary appendicular bone tumours compared to long bone survey radiography, bone scintigraphy and thoracic radiographs. Fifteen dogs were included in this pilot study. A construct reference standard was used for detection of bone metastasis, and negative thoracic radiographs were compared against CT. Definitive lesions were only identified on bone scintigraphy. Not all lesions agreed with the construct reference standard. No definitive lesions were identified on survey radiographs or CT. Lesions were identified on thoracic CT that were not visible radiographically. Equivocal ground glass pulmonary lesions progressed in three of four cases. Whole body CT was not a suitable alternative to bone scintigraphy; however, it was useful as an adjunctive diagnostic modality. Pulmonary lesions were visible on CT that were not seen radiographically and ground glass pulmonary lesions in dogs should be considered suspicious for metastasis.

Complications after intramedullary nailing of femoral fractures in a low-income country.

BACKGROUND: Some surgeons believe that internal fixation of fractures carries too high a risk of infection in low-income countries (LICs) to merit its use there. However, there have been too few studies from LICs with sufficient follow-up to support this belief. We first wanted to determine whether complete follow-up could be achieved in an LIC, and secondly, we wanted to find the true microbial infection rate at our hospital and to examine the influence of HIV infection and lack of follow-up on outcomes. PATIENTS AND METHODS: 137 patients with 141 femoral fractures that were treated with intramedullary (IM) nailing were included. We compared outcomes in patients who returned for scheduled follow-up and patients who did not return but who could be contacted by phone or visited in their home village. RESULTS: 79 patients returned for follow-up as scheduled; 29 of the remaining patients were reached by phone or outreach visits, giving a total follow-up rate of 79%. 7 patients (5%) had a deep postoperative infection. All of them returned for scheduled follow-up. There were no infections in patients who did not return for follow-up, as compared to 8 of 83 nails in the group that did return as scheduled (p = 0.1). 2 deaths occurred in HIV-positive patients (2/23), while no HIV-negative patients (0/105) died less than 30 days after surgery (p = 0.03). INTERPRETATION: We found an acceptable infection rate. The risk of infection should not be used as an argument against IM nailing of femoral fractures in LICs. Many patients in Malawi did not return for follow-up because they had no complaints concerning the fracture. There was an increased postoperative mortality rate in HIV-positive patients.

Low central venous oxygen saturation is associated with increased mortality in critically ill dogs.

OBJECTIVES: To investigate relationships between central venous oxygen saturation (ScvO(2)) and survival to hospital discharge in dogs. Central venous oxygen saturation is an accessible measure of the balance between systemic oxygen delivery and consumption. METHODS: Prospective observational cohort study, enrolling 126 client-owned dogs with central venous catheters. Central venous oxygen saturation was measured over the 24 hours following intensive care unit admission. Poor outcome was defined as death or euthanasia performed for moribund status. Regression analysis identified independent predictors of non-survival and physiologic parameters associated with central venous oxygen saturation. Area under the receiver operator curve analysis identified a cut-off point of central venous oxygen saturation, below which central venous oxygen saturation decrease was associated with increased mortality risk. RESULTS: Mortality risk was 30·9%. Low central venous oxygen saturation was associated with poor outcome (P<0·05). Area under the receiver operator curve analysis selected a central venous oxygen saturation of 68% as the point below which a fall in central venous oxygen saturation was associated with increased mortality risk. For each 10% drop in central venous oxygen saturation below 68%, odds of non-survival increased by 2·66 times (P=0·0002, 95% confidence interval of odds ratio=1·45 to 4·85). Central venous oxygen saturation was equivalent to lactate in predicting non-survival. Predictors of central venous oxygen saturation (packed cell volume, mean arterial blood pressure, fever, % arterial haemoglobin saturation as measured by pulse oximeter) were consistent with hypothesised physiologic mechanisms. CLINICAL SIGNIFICANCE: Central venous oxygen saturation was a strong mortality predictor. Further work is needed to determine if therapy targeting central venous oxygen saturation can reduce mortality in canine intensive care unit patients.

The Feline Acute Patient Physiologic and Laboratory Evaluation (Feline APPLE) Score: a severity of illness stratification system for hospitalized cats.

BACKGROUND: Scores allowing objective stratification of illness severity are available for dogs and horses, but not cats. Validated illness severity scores facilitate the risk-adjusted analysis of results in clinical research, and also have applications in triage and therapeutic protocols. OBJECTIVE: To develop and validate an accurate, user-friendly score to stratify illness severity in hospitalized cats. ANIMALS: Six hundred cats admitted consecutively to a teaching hospital intensive care unit. METHODS: This observational cohort study enrolled all cats admitted over a 32-month period. Data on interventional, physiological, and biochemical variables were collected over 24 hours after admission. Patient mortality outcome at hospital discharge was recorded. After random division, 450 cats were used for logistic regression model construction, and data from 150 cats for validation. RESULTS: Patient mortality was 25.8%. Five- and 8-variable scores were developed. The 8-variable score contained mentation score, temperature, mean arterial pressure (MAP), lactate, PCV, urea, chloride, and body cavity fluid score. Area under the receiver operator characteristic curve (AUROC) on the construction cohort was 0.91 (95% CI, 0.87-0.94), and 0.88 (95% CI, 0.84-0.96) on the validation cohort. The 5-variable score contained mentation score, temperature, MAP, lactate, and PCV. AUROC on the construction cohort was 0.83 (95% CI, 0.79-0.86), and 0.76 (95% CI, 0.72-0.84) on the validation cohort. CONCLUSIONS AND CLINICAL IMPORTANCE: Two scores are presented enabling allocation of an accurate and user-friendly illness severity measure to hospitalized cats. Scores are calculated from data obtained over the 1st 24 hours after admission, and are diagnosis-independent. The 8-variable score predicts outcome significantly better than does the 5-variable score.

Osteosarcoma masked by osteomyelitis and cellulitis in a dog.

CASE DESCRIPTION: This clinical report describes a 10-year-old female spayed German Shepherd dog cross that was presented with cellulitis of the left proximal forelimb and osteomyelitis of the left proximal humerus, and was ultimately diagnosed with metastatic osteosarcoma. CLINICAL FINDINGS: The diagnosis of cellulitis and osteomyelitis was made using ultrasound, radiography, cytology and histopathology, all of which were consistent with cellulitis and osteomyelitis. Cultures were negative. TREATMENT: The patient was treated using two surgical debridements and long-term broad-spectrum antibiotic drugs. Despite surgical and medical treatment, the dog's condition progressed. A lytic lesion of the left proximal humerus was identified radiographically. OUTCOME: One hundred forty-one days after initial presentation, the dog was presented with a non-weight bearing lameness of the left forelimb. An amputation was scheduled. Preoperative computed tomography scan of the thorax revealed gross metastatic disease to the lungs. The patient was euthanatized and a post-mortem examination revealed osteosarcoma of the left proximal humerus with widespread metastasis. CLINICAL RELEVANCE: To our knowledge, this case is the first reported case of osteomyelitis masking osteosarcoma in a dog. It serves as a reminder to maintain a high index of suspicion when managing cases with a signalment, history and radiographic lesion that are consistent with a primary bone tumour.

The acute patient physiologic and laboratory evaluation (APPLE) score: a severity of illness stratification system for hospitalized dogs.

BACKGROUND: Objective risk stratification models are used routinely in human critical care medicine. Applications include quantitative and objective delineation of illness severity for patients enrolled in clinical research, performance benchmarking, and protocol development for triage and therapeutic management. OBJECTIVE: To develop an accurate, validated, and user-friendly model to stratify illness severity by mortality risk in hospitalized dogs. ANIMALS: Eight hundred and ten consecutive intensive care unit (ICU) admissions of dogs at a veterinary teaching hospital. METHODS: Prospective census cohort study. Data on 55 management, physiological, and biochemical variables were collected within 24 hours of admission. Data were randomly divided, with 598 patient records used for logistic regression model construction and 212 for model validation. RESULTS: Patient mortality was 18.4%. Ten-variable and 5-variable models were developed to provide both a high-performance model and model maximizing accessibility, while maintaining good performance. The 10-variable model contained creatinine, WBC count, albumin, SpO(2) , total bilirubin, mentation score, respiratory rate, age, lactate, and presence of free fluid in a body cavity. Area under the receiver operator characteristic (AUROC) on the construction data set was 0.93, and on the validation data set was 0.91. The 5-variable model contained glucose, albumin, mentation score, platelet count, and lactate. AUROC on the construction data set was 0.87, and on the validation data set was 0.85. CONCLUSIONS AND CLINICAL IMPORTANCE: Two models are presented that enable allocation of an accurate and user-friendly illness severity index for dogs admitted to an ICU. These models operate independent of primary diagnosis, and have been independently validated.

Diagnosing the etiology of hypercalcemia in a dog: a case of primary hyperparathyroidism.

A 13-year-old spayed Labrador Retriever cross dog presented for polyuria and polydipsia. Serum total calcium, free calcium, and intact parathyroid hormone concentrations were elevated. Surgical exploration of the ventral neck revealed a grossly enlarged right external parathyroid gland. The histopathological diagnosis for the excised right parathyroid gland was an incompletely resected parathyroid carcinoma. Parathyroid carcinoma in the dog is an infrequent cause of hypercalcemia and primary hyperparathyroidism.

Lameness in a dog caused by thoracic wall invasion by a pulmonary neoplasm.

A 12-year-old fox-terrier dog presented with forelimb lameness of 3-weeks duration. Ultrasonography revealed a mass within the thoracic wall and osteolysis of the left third rib. A squamous cell carcinoma was diagnosed by cytological examination of an ultrasound-guided fine needle aspirate of this mass. As a result of the diagnosis of neoplasia, the dog was euthanatized. Necropsy revealed a solitary expansile mass within the left cranial lung lobe, and a mass within the adjacent thoracic wall. Thickening of the pleura between the two masses was visible, although adhesions were not present. Histology of both masses revealed a well-differentiated squamous cell carcinoma. To the authors' knowledge, this is the first detailed description of direct invasion of the thoracic wall by a canine lung tumour.

Consumption of deoxynivalenol-contaminated wheat by mallard ducks under experimental conditions.

Captive mallards (Anas platyrhynchos) were fed wheat containing 5.8 ppm deoxynivalenol (DON, vomitoxin) from an outbreak of Fusarium graminearium head-blight that occurred on grain crops in Manitoba, Canada, during 1993. There was no evidence of taste aversion to this grain during a 10-day palatability trial. No significant differences were detected in serum protein, calcium, glucose, creatinine kinase, aspartate aminotransferase or uric acid levels, blood packed cell volume, or body or organ weight, between ducks fed contaminated wheat and those fed uncontaminated wheat during a 14-day feeding trial. No gross or microscopic lesions were detected in birds fed contaminated wheat for 14 days. Based on these results, ducks will consume grain containing moderate levels of DON and short-term exposure to this grain will not result in obvious adverse effects.