Kenita S. Rogers

Transmissible Venereal Tumor: A Retrospective Study of 29 Cases

Twenty-nine cases of naturally occurring, transmissible venereal tumor were studied retrospectively. The external genitalia was the primary site of tumor involvement in 27 dogs, with the remaining two dogs having primary intranasal involvement. Extragenital tumor involvement was identified in six cases, including five cases with metastatic disease. Fifteen cases were treated effectively with radiation therapy alone. Radiation therapy also was effective in four cases that were resistant to chemotherapy. Four of five cases treated with at least four doses of vincristine as a solitary agent also achieved complete remissions. Transmissible venereal tumor remains a unique canine tumor that often is curable despite the development of extragenital primary lesions or metastasis.

Mast Cell Tumors: Dilemmas of Diagnosis and Treatment

Making the most appropriate choices for diagnosis and treatment of canine and feline mast cell tumors remains challenging. An understanding of the heterogeneity of the disease process, the associated paraneoplastic disorders, and the known prognostic indicators can be helpful in making rational decisions regarding each individual case. A multimodality approach may be needed for optimal care of some patients, but the effectiveness of current medical treatment strategies continues to limit our ability to cure disseminated forms of disease.

Doxorubicin induced expression of P-glycoprotein in a canine osteosarcoma cell line.

Canine and human osteosarcoma are very similar with respect to clinical presentation, radiological and histopathological features, metastatic rate and pattern and response to therapy. For these reasons, canine osteosarcoma is a useful intermediate model for the disease in humans. Overexpression of P-glycoprotein, the product of the MDR1 gene, is the most important predictor of an adverse clinical course in human patients with osteosarcoma. Exposure of canine osteosarcoma cells to doxorubicin resulted in overexpression of MDR1 mRNA and P-glycoprotein. Furthermore, these cells failed to accumulate doxorubicin intracellularly and were less sensitive to vincristine-induced cytotoxicity as compared to parental cells.

Primary intratracheal lymphosarcoma in four cats.

Four cats presented with clinical signs suggestive of respiratory disease, including dyspnea, wheezing, cyanosis, inspiratory stridor, coughing, and gagging. Radiographs revealed intratracheal masses. Bronchoscopy allowed for lesion localization and collection of samples for cytopathological and histopathological evaluation, which confirmed a diagnosis of lymphosarcoma. Cats treated with systemic chemotherapy or radiation were able to achieve complete remission and long-term resolution of clinical signs.

Survival Data for Canine Oral Extramedullary Plasmacytomas: A Retrospective Analysis (1996–2006)

In a 10-year period, extramedullary plasmacytomas (EMP) represented 5.2% of all oral tumors found in the dog (16/302). These 16 oral EMP comprised 28.5% of all EMP within the same time period. Eleven dogs died with a median survival time of 474 days. Five dogs remain alive at the time of this writing. Dogs without complete surgical removal of the EMP and no adjuvant therapy had a median survival time of 138 days. Oral EMP have a clinical behavior consistent with EMP arising from other tissues. They have no obvious correlation with multiple myeloma, and complete surgical resection may be curative.

Nephrotic Syndrome Resulting in Thromboembolic Disease and Disseminated Intravascular Coagulation in a Dog

Thromboembolic disease and progression to disseminated intravascular coagulation (DIC) are potential life-threatening complications for dogs with nephrotic syndrome. Platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), plasma concentration of fibrinogen degradation products (FDPs), antithrombin III (ATIII), protein C, and plasminogen were used to identify hemostatic abnormalities in a dog with nephrotic syndrome. Pulmonary thromboembolic disease was diagnosed by thoracic radiography, arterial blood gas analysis, and pulmonary scintigraphy. Prompt recognition and treatment of hemostatic complications is necessary in dogs with nephrotic syndrome.

Platelet Aggregation and Adenosine Triphosphate Secretion in Dogs with Untreated Multicentric Lymphoma

Whole-blood platelet aggregation and adenosine triphosphate secretion were measured in 15 dogs with untreated multicentric lymphoma and 10 normal control dogs to determine if dogs with lymphoma have altered platelet function. Dogs with quantitative platelet disorders (ie, thrombocytopenia or thrombocytosis) or with clinical evidence of a bleeding disorder were excluded from the study. Platelets from affected dogs had significantly greater maximum aggregation than those from control dogs, suggesting that platelets from dogs with lymphoma are hyperactive. Platelet hyperactivity may play a role in the development of hemostatic disorders (eg, disseminated intravascular coagulation) or in tumor metastasis. Further investigation is needed to determine if modification of platelet function in patients with lymphoma affects disease progression or outcome.

Telomerase Enzyme Activity as a Diagnostic Tool to Distinguish Effusions of Malignant and Benign Origin

Telomerase enzyme activity is high in populations of cells that are dividing, and is low or undetectable in quiescent cell populations. Activation of telomerase in tissues that normally lack the capacity for self-renewal is strongly correlated with neoplasia. Telomerase activity can be detected in samples containing very small numbers of cells and studies of human patients suggest that measurement of telomerase activity may be useful for the evaluation of samples that can be obtained in a minimally invasive manner. This study compares the presence or absence of telomerase activity with cytologic evaluation of body cavity effusions, to determine if neoplasia is the underlying cause for the effusion in dogs and cats. Detection of telomerase in effusions was no more sensitive than cytologic evaluation for the identification of underlying neoplasia, and was less specific (telomerase assay: sensitivity = 50%, specificity = 83%; cytology: sensitivity = 50%, specificity = 100%). We conclude that although the telomerase assay may constitute a useful adjunctive test for the diagnosis of neoplasia in some dogs and cats with body cavity effusions, the results of this assay are not sufficiently reliable to be used as a sole diagnostic test.

Adverse Childhood Experiences among Veterinary Medical Students: A Multi-Site Study

This research explores Adverse Childhood Experiences (ACEs) among veterinary medical students across six academic institutions of veterinary medicine, and their relationship with depression, stress, and desire to become a veterinarian. Between April 1, 2016, and May 23, 2016, 1,118 veterinary medical students in all 4 years of the curriculum (39% response rate) completed an anonymous web-based questionnaire about ACEs, depression using the Center for Epidemiological Studies Depression scale (CESD), stress using the Perceived Stress Scale (PSS), and the age at which they wanted to become a veterinarian. Sixty-one percent (677) of respondents reported having at least one ACE. The most prevalent ACE reported was living with a household member with a mental illness (31%). Students who had experienced four or more ACEs had an approximately threefold increase in signs of clinical depression and higher than average stress when compared to students who had experienced no ACEs. The number of ACEs showed an overall graded relationship to signs of clinical depression and higher than average stress. There was no statistically significant relationship between age at which a student wanted to become a veterinarian and exposure to ACEs. Veterinary students report being exposed to ACEs before age 18 at a rate similar to that of other population-based studies. These findings do not suggest that veterinary students enter the veterinary medical education system more at risk for poor mental health due to ACEs than the general population.

Merging Clinical Cases, Client Communication, and Physiology to Enhance Student Engagement, Learning, and Skills

Understanding disease processes, making diagnoses, and guiding clinical therapy are predicated on an understanding of normal physiologic function. However, we have observed that many first-year students fail to appreciate the important role that a clear understanding of normal function plays in becoming well-prepared, practicing veterinarians. Students also struggle with application of basic knowledge to the diagnosis and treatment of disease, as evidenced by poor performance on exam questions requiring application. The purpose of this project was to help students link the physiologic concepts in the classroom with clinical application, as well as to improve their ability to explain those concepts to a client. We found that, as a result of this assignment, students developed a deeper understanding of physiologic processes and their clinical relevance and, subsequently, felt more confident conveying this knowledge to simulated clients. Implementation of this case project has been very well received by the students. Students improved their grasp of the material, and they indicated that the project contributed positively to their motivation to study and learn physiology.