Gastroesophageal intussusception in a Labrador retriever.

A 14-month-old, intact male Labrador retriever was referred for evaluation of vomiting and regurgitation. A diagnosis of gastroesophageal intussusception with aspiration pneumonia was made. The patient responded favorably to aggressive surgical and medical management. The guarded to poor prognosis for gastroesophageal intussusception makes the successful outcome of this case unique.

Closed reduction and type-II external fixation of comminuted fractures of the radius and tibia in dogs: 23 cases (1990-1994).

OBJECTIVE: To describe a technique for closed reduction of and application of a type-II external fixator to comminuted fractures of the radius and tibia in dogs and to evaluate outcome of the technique in a series of client-owned dogs. DESIGN: Retrospective case series. ANIMALS: 23 dogs that underwent closed reduction of severely comminuted (> or = 5 fragments); mid-diaphyseal radial (n = 9); and tibial (n = 14) fractures and stabilization with a type-II external fixator. PROCEDURE: Radiographs were made postoperatively and every 4 to 6 weeks until the fixator was removed. The effect of type of fracture (open vs closed), type of pins (threaded vs smooth), and number of fixation pins on surgery time, time between surgery and development of bridging callus, and time between surgery and removal of the fixator was evaluated using one-sided Student's t-tests. RESULTS: 21 fractures healed after a single surgery. Two dogs with radial fractures required a second procedure because of complications. All fractures healed with the original fixation device in place. Mean time between surgery and the development of bridging callus was 11.4 weeks (range, 4 to 22 weeks), and mean time between surgery and fixator removal was 14.7 weeks (range, 4 to 27 weeks). Type of fracture, type of pins, and number of fixation pins did not have a significant effect on surgery time, time to development of bridging callus, or time to fixator removal. CLINICAL IMPLICATIONS: Closed reduction and application of a type-II external fixator was an effective method of treating severely comminuted radial and tibial fractures.

Primary epitheliotropic alimentary T-cell lymphoma with hepatic involvement in a dog.

The anatomic forms of lymphoma are multicentric, alimentary, thymic, cutaneous, and leukemic. Correlations between cell type and topographic distribution of lymphomas is not well documented, but there are more plasmacytoid tumors in the gut, skin, and spleen, which suggests that these are areas of malignant transformation preceded by a period of benign immune hyperplasia. Alimentary forms of lymphoma can be preceded by lymphocytic-plasmacytic enteritis. In the present case, an epitheliotropic alimentary form of T-cell lymphoma with hepatic involvement and concomitant lymphocytic-plasmacytic enteritis was diagnosed in an 8-year-old male Labrador Retriever. The lymphoma was characterized by the accumulation of atypical lymphocytes in the lamina propria and mucosal epithelium of the jejunum. The lymphocytes were identified as T-cell lineage using a polyclonal rabbit antisera to the human pan-T-cell determinant CD-3. The "homing" nature of the neoplasm resembles the epidermotropic form of cutaneous T-cell lymphoma.

Evaluation of marking materials for cutaneous surgical margins.

Microscopic evaluation of the margins of excised cutaneous neoplasms is of paramount importance for determining that neoplastic tissue does not extend to the excision borders. Dyes or pigments that indelibly mark the tissue should be more reliable than sectioning techniques or suture markers for identifying the surgical margins before and after tissue processing. We evaluated 5 pigments to select a material that could be rapidly applied by surgeons, and readily identified on histologic section by the pathologists. Twenty normal canine skin specimens were assigned to each of 5 groups. Each group was treated with artists' pigments in acetone, India ink in acetone, alcian blue, typists' correction fluid, or a commercially available marking kit. Ten specimens within each group were marked before formalin fixation, and 10 were marked after fixation. Application properties, fixation and processing properties, and microscopic characteristics were evaluated for each material. Application properties were acceptable for all marking materials on unfixed specimens, and for alcian blue, India ink in acetone, and correction fluid on fixed specimens. Fixation and processing properties were acceptable for all materials except correction fluid. All marking materials survived fixation and processing, and colors were readily visualized under the microscope. Microscopic characteristics were acceptable for alcian blue, India ink in acetone, and the commercial kit. Overall, alcian blue was the best marking material, with India ink in acetone and the commercial kit also acceptable. Correction fluid and artist' pigments in acetone were not acceptable because pigment fragmentation and incomplete tissue coverage hindered microscopic evaluation of resection margins.

Bovine fetal infection with Mycobacterium paratuberculosis.

In utero transmission of Mycobacterium paratuberculosis, the causative agent of paratuberculosis in cattle, has been suggested. Tissue specimens were obtained at a packing plant from pregnant dairy cows and their fetuses and from cows with clinical signs of paratuberculosis and from their fetuses. Specimens were processed according to methods described for isolating M paratuberculosis from bovine tissues and were incubated on Herrold egg yolk medium for 16 weeks. Presumed positive specimens were confirmed to be M paratuberculosis, using acid-fast staining and subculturing. Of 407 lymph nodes from cows, 34 (8.4%) were culture positive for M paratuberculosis; 9 of 34 (26.4%) of these culture-positive cows had fetuses from which specimens were also culture positive. The results estimated the risk of fetal infection with M paratuberculosis to be 26.4% (95% confidence interval between 11.3 and 40.7%).