Evaluation of an in-house centrifugal hematology analyzer for use in veterinary practice.

OBJECTIVE: To compare CBC results obtained by use of an in-house centrifugal analyzer with results of a reference method. DESIGN: Prospective study. SAMPLE POPULATION: Blood samples from 147 dogs, 42 cats, and 60 horses admitted to a veterinary teaching hospital and from 24 cows in a commercial dairy herd. PROCEDURE: Results obtained with the centrifugal analyzer were compared with results obtained with an electrical-impedance light-scatter hematology analyzer and manual differential cell counting (reference method). RESULTS: The centrifugal analyzer yielded error messages for 50 of 273 (18%) samples. Error messages were most common for samples with values outside established reference ranges. Correlation coefficients ranged from 0.80 to 0.99 for Hct, 0.55 to 0.90 for platelet count, 0.76 to 0.95 for total WBC count, and 0.63 (cattle) to 0.82 (cats) to 0.95 (dogs and horses) for granulocyte count. Coefficients for mononuclear cell (combined lymphocyte and monocyte) counts were 0.56, 0.65, 0.68, and 0.92 for cats, horses, dogs, and cattle, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that there was an excellent correlation between results of the centrifugal analyzer and results of the reference method only for Hct in feline, canine, and equine samples; WBC count in canine and equine samples; granulocyte count in canine and equine samples; and reticulocyte count in canine samples. However, an inability to identify abnormal cells, the high percentage of error messages, particularly for samples with abnormal WBC counts, and the wide confidence intervals precluded reliance on differential cell counts obtained with the centrifugal analyzer.

Tissue reactivity to poliglecaprone 25 in the feline linea alba.

OBJECTIVE: To use poliglecaprone 25 for all ligations and closure in routine feline ovariohysterectomies and evaluate maintenance of tissue approximation and tissue reaction to the suture. STUDY DESIGN: Prospective, descriptive study. ANIMALS: Twenty four female cats. METHODS: Ovariohysterectomies were performed in all cats. Abdominal incisions were inspected on days 1, 3, 7, 14, and 28 for dehiscence and swelling. All cats were euthanatized postoperatively, group 1 on day 7; group 2 on day 14; and group 3 on day 28. The peritoneal cavity was inspected for adhesions and all abdominal incisions were collected en bloc. Each linea alba was histologically evaluated and the inflammatory reaction was characterized. RESULTS: Dehiscence did not occur in any of the 24 cats. The incisional swelling on day 1 was significantly smaller than on day 7, and the swelling on day 14 was significantly smaller than on days 1, 3, and 7 (P < .05). Intra-abdominal adhesions were found in all groups with the greatest number associated with the peritoneum at the incision site. Tissue reactions in group 1 were pyogranulomatous or fibromononuclear, group 2 were granulomatous or fibromononuclear, and group 3 were pyogranulomatous, granulomatous, fibromononuclear or fibrous. Eosinophilic infiltration was seen in 3 of the 8 cats in group 1. CONCLUSIONS: Incisional swelling and inflammatory reactions seen with poliglecaprone 25 were consistent with those anticipated after implantation of suture in a surgically created wound. CLINICAL RELEVANCE: Poliglecaprone 25 appears to be an acceptable suture for use in feline ovariohysterectomy. It causes a relatively short-lived inflammatory response.

Equine malignant lymphomas: morphologic and immunohistochemical classification.

Gross lesions, microscopic appearance, and immunophenotyping are reported in a retrospective study of 31 cases of equine malignant lymphoma. Immunohistochemical studies were performed on archived formalin-fixed, paraffin-embedded tissues. Monoclonal antibodies to surface glycoprotein BLA.36 and intracytoplasmic domains of mb-1 and B29 were used to document the presence of B lymphocytes in the equine tumors. Polyclonal antibody to CD3 and monoclonal antibodies to T-lymphocyte markers CD3 and CD5 revealed the presence of variable numbers of T cells within the equine lymphomas. The neoplastic component of the equine lymphomas was determined through morphologic evaluation, immunophenotyping, and the use of proliferation markers Ki-67 and proliferating cell nuclear antigen. Equine malignant lymphomas were composed of a heterogeneous cell population. Most tumors contained B and T lymphocytes. Twenty-four horses had diffuse lymphomas derived from B lymphocytes. Thirteen of these lymphomas contained primarily neoplastic B lymphocytes. Eleven additional cases of diffuse large B-cell lymphoma contained from 40% to 80% nonneoplastic T lymphocytes and were classified as T-cell-rich, large B-cell lymphomas. This is the first description of T-cell-rich, B-cell lymphoma in the horse. Six tumors with a diffuse architecture were derived from T lymphocytes. Four T-cell tumors were large-cell tumors, 1 was a small-cell tumor, and in 1 tumor the size of the cells could not be determined accurately because of autolytic change in the tissues. One diffuse large-cell lymphoma did not react with either B- or T-cell markers.

Extramedullary plasmacytoma in the trachea of a dog.

A 10-year-old spayed female mixed-breed dog was examined because of acute inspiratory dyspnea. Radiography and tracheoscopy revealed a discrete, solitary mass originating from the membranous portion of the trachea at the level of the thoracic inlet. Tracheal resection and anastomosis were performed, and on histologic examination of the resected tissue, extramedullary plasmacytoma was diagnosed. Although tracheal tumors are rare in dogs, they should be considered during evaluation of dogs with signs of airway obstruction. Prognosis is excellent for dogs with extramedullary plasmacytoma in which surgical excision is complete.

Detection of equine and bovine T- and B-lymphocytes in formalin-fixed paraffin-embedded tissues.

Formalin-fixed paraffin-embedded sections of equine and bovine lymph nodes, spleen, thymus, and Peyer's patches were incubated with monoclonal antibodies to B-lymphocyte markers BLA.36, B29, and mb-1 and T-lymphocyte markers CD3 and CD5. The monoclonal antibody BLA.36 reacted with 80-90% of lymphocytes in the germinal centers and mantle zones of follicles in lymph nodes, spleen, and Peyer's patches. In addition, 90% of lymphocytes in the marginal zone of the spleen, and variable numbers of lymphocytes within lymph node medullary cords were immunopositive for BLA.36. Antibodies to B29 and mb-1 produced similar staining patterns as BLA.36 with fewer positive cells in the germinal centers and medullary cords. BLA.36, B29, and mb-1 reacted with 30-50% of lymphocytes in the medulla of the thymus and with 5-10% of lymphocytes in the cortex. CD3 and CD5 reacted with 90% of lymphocytes in the paracortex and parafollicular zones of lymph nodes, spleen, and Peyer's patches; 40-50% of lymphocytes in the medullary cords of lymph nodes, and scattered positive cells within follicles. Anti-CD3 antibody reacted with 95% of lymphocytes in the splenic red pulp, but antibodies directed against CD5 reacted only faintly with approximately 5-10% of lymphocytes in the red pulp. CD3 and CD5 reacted with 50-60% of cells in the medulla of the thymus and with 40-80% of lymphocytes in the thymic cortex. The biochemical characterization of the antibodies by Western blotting against lysates of equine and bovine peripheral blood mononuclear cells confirmed that antibodies to BLA.36, mb-1, B29, CD3, and CD5 detected molecules of the same approximate molecular mass as found on lymphoid cells of human beings and rats.

Surgical treatment of a septic dentigerous cyst in a goat.

A slowly growing lesion of the rostral mandible of a goat was diagnosed to be a septic dentigerous cyst. The lesion was treated surgically to remove one displaced tooth and debride the cystic cavity, and systemic antibiotic therapy was applied. Thirty-four weeks later the goat was clinically and radiographically improved and the problem had not recurred.

Hepatobiliary scintigraphy in the evaluation of feline liver disease.

Hepatobiliary scintigraphy (HBS) was performed in 10 cats with histologically documented hepatobiliary disease. The scintigraphic patterns were classified into one of 5 categories: normal, primary hepatocellular dysfunction, primary intrahepatic cholestasis, mixed hepatocellular and intrahepatic cholestasis, and extrahepatic obstructive patterns. Initial attempts were made to correlate specific disease entities with HBS patterns, but a consistent relationship could not be determined. A correlation between the histological severity of a given hepatic disease and the HBS pattern was made. All cats (n = 5) with a mixed hepatocellular and intrahepatic cholestasis scintigraphic pattern with normal gallbladder function had a histologically severe form of their individual hepatic disease. Three of the 4 cats with an intrahepatic cholestasis pattern and normal hepatocellular and gallbladder function had histologically mild or moderate forms of their individual hepatic diseases. One cat had an extrahepatic obstructive pattern where no radiopharmaceutical was identified in the gallbladder or small intestine by 3 hours postinjection. This study suggests that HBS can be useful in cats with hepatobiliary disease to assess the severity of hepatic dysfunction, and to determine if extrahepatic biliary obstruction is present. Correlation between HBS patterns and specific disease entities such as hepatic lipidosis or cholangitis-cholangiohepatitis syndrome could not be made in this study.

Accuracy of interpretation of microscopic images of cytologic, hematologic, and histologic specimens using a low-resolution desktop video conferencing system.

OBJECTIVE: To determine the accuracy of interpretation of microscopic images for pathologic study transmitted over Switched-56 lines using a desktop interactive video conferencing system. MATERIALS AND METHODS: In subjective studies, two systems were connected using null-modem cables, which allowed evaluation of different bandwidths from 56 kbps to 384 kbps. Objective studies were done with two systems connected at distant sites via paired Switched-56 lines that produced an effective bandwidth of 112 kbps. A video camera mounted on a microscope was attached to the sending system. The resolution of the video image on the video conferencing system was 352 x 288 lines. Cases for cytology, hematology, and histopathology studies were selected from archives; one pathologist transmitted microscopic images, and a second pathologist made interpretations. The three pathologists were Board certified with similar experience that ranged from 20 to 35 years. Categories of interpretations or observations were predetermined for each study to allow the data on agreement between the direct microscopic interpretation or observation and that recorded by the receiving pathologist to be corrected for agreement attributable to chance alone. The results were analyzed using the kappa statistic. RESULTS: In the subjective studies, image degradation prevented interpretation while the microscope stage was moved. This problem occurred at all bandwidths tested. Image quality limited microscopic details. Organisms < 1 micron in diameter could not be seen reliably. In objective cytologic studies, overall agreement was recorded on 89 of 99 observations. In the four categories of specimens, observed agreement ranged from 0.778 to 0.958, and kappa was 0.704 to 0.948. For hematology specimens, overall agreement was found on 69 of 80 observations; observed agreement on eight types of nucleated blood cells ranged from 0.5 to 1.0, and kappa was 0.429 to 1.0. Poorer color definition and image quality prevented accurate identification of lymphoblasts and eosinophils in particular. For histologic specimens, overall agreement was obtained on 56 of 66 observations, observed agreement on four categories of histologic change ranged from 0.73 to 0.93, and kappa was 0.47 to 0.9. CONCLUSIONS: The desktop interactive video conferencing system, as configured in this study, was unsuitable for making definitive diagnoses from transmitted microscopic images.

Neurological manifestations of hypothyroidism: a retrospective study of 29 dogs.

Neuromuscular signs in association with hypothyroidism are described in 29 dogs. Eleven dogs had lower motor neuron signs, 9 had peripheral vestibular deficits, 4 had megaesophagus, and 5 had laryngeal paralysis. Primarily older (mean = 9.5 years), large-breed dogs were affected, and there was no sex or breed predisposition. Duration of clinical signs before presentation ranged from 2 to 8 weeks (mean = 5 weeks). The diagnosis was based on (1) results of neurological examination (29 dogs); (2) electromyographic abnormalities (18 dogs), including fibrillation potentials (n = 18), positive sharp waves (n = 15), and complex repetitive discharges (n = 4); (3) high serum cholesterol concentration (10 dogs; mean = 335 mg/dL); (4) low response to thyroid-stimulating hormone (29 dogs; mean T4 prestimulation concentration = 0.8 micrograms/dL; mean T4 poststimulation = 1.2 microgram/dL); and (5) good response to thyroxine supplementation (26 dogs). Dogs with vestibular deficits had abnormal brainstem auditory-evoked responses (BAER), including increased latencies of P1-P6 and decreased amplitude of P4,5-N5. Seven other dogs had similar BAER abnormalities without manifesting clinical signs of vestibular involvement. Three dogs with vestibular signs had fibrillation potentials and positive sharp waves without exhibiting lower motor neuron signs. All dogs were supplemented with levothyroxine (0.02 mg/kg PO bid). The follow-up period ranged between 6 and 30 months (mean, 14 months). Serum T4 concentrations were measured at least 3 times for each dog every 2 months (mean T4 concentration = 2.6 micrograms/dL). All but 1 dog with lower motor neuron signs and 1 dog with vestibular signs recovered after 2 months (mean, 57 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Microcytosis and iron status in dogs with surgically induced portosystemic shunts.

Microcytosis is common in dogs with congenital portosystemic shunts (PSS) and acquired liver disease. The objective of this study was to determine if microcytosis could be induced in normal dogs by surgical creation of PSS, and to characterize the changes in hematology and iron status. Hematocrit, mean cell volume, mean cell hemoglobin, and mean cell hemoglobin concentration decreased linearly from 45.5%, 69.1 fL, 22.8 g/dL and 33.1% to 39.5%, 55.9 fL, 17.8 g/dL and 31.9%, respectively, 18 weeks after creation of PSS. The erythrocyte count did not change, but red cell distribution widths indicated a shift to a heterogenous population with decreased volume. Mean cell volume and mean cell hemoglobin decreased rapidly after induction of PSS and were significantly (P < .05) different from presurgery values within 2 weeks. Serum iron and copper concentrations and total iron binding capacity were decreased in dogs with PSS. Liver iron concentration doubled after creation of PSS, with the majority of stainable iron located in Kupffer cells. The changes in erythrocyte indices and measures of iron status in dogs with surgically induced PSS were similar to those in dogs with congenital PSS. Microcystosis developed rapidly in dogs after induction of PSS. These results indicate that iron deficiency was not the cause of microcytosis in these dogs.

Age-related characteristics of gastric squamous epithelial mucosa in foals.

Specimens of grossly normal gastric stratified squamous epithelial mucosa adjacent to the margo plicatus on the right side and along the greater curvature were obtained from 7 foetuses, 10 term foals and 12 foals 2-35 days old. Gastric squamous epithelium from the foetuses changed markedly during gestation. At 150-270 days, the epithelium was 8-10 cells thick, with a single layer of basal cells. Epithelial cells were polyhedral and had abundant clear or slightly stained cytoplasm. In the 300-day foetus the basal layer was thicker, epithelial cells were polyhedral, and there was a flattened 1 cell-thick layer superficially. In the 335-day foetus, the epithelial cells were flat and there was a superficial layer of keratinised cells, 1-2 cells thick. In term foals, the gastric epithelium consisted of 10-12 cell layers, with 4-5 thin layers of surface keratin. Epithelial projections (papillae) were either absent or not pronounced. The gastric epithelium became thicker with increasing age, including increased epithelial cell layers, thickening of the keratinised layers, and more pronounced papillae. Desquamation was observed in the keratinised layers of gastric squamous epithelium from foals > or = 2 days of age.

Effects of 5% and 10% guaifenesin infusion on equine vascular endothelium.

Twelve horses of various breeds and either sex were anesthetized with xylazine and ketamine injected into a median or lateral thoracic vein. During anesthesia, with the horse in sternal recumbency, a 14-gauge, 8.9 cm catheter was inserted into each jugular vein by using aseptic technique. Guaifenesin in water (100 mg/kg or a maximum dose of 50 grams) was infused into one jugular vein and an equal volume of 0.9% saline solution was infused into the other jugular vein. Seven horses received 10% guaifenesin, and five horses received 5% guaifenesin. The catheters were removed before the horses recovered from anesthesia. The horses were euthanatized approximately 48 hours later, and the jugular veins were removed for histologic examination. Adherent thrombus material was observed in all veins exposed to 10% guaifenesin and in one vein exposed to 5% guaifenesin. No evidence of thrombus was observed in four veins infused with 5% guaifenesin or in those infused with saline solution. These findings are of particular significance with horses at increased risk for thrombosis or thrombophlebitis.

Hematologic and serum biochemical effects of long-term administration of anti-inflammatory doses of prednisone in dogs.

Results of routine hematologic and serum biochemical analyses from 12 healthy adult male dogs that were given prednisone (0.55 mg/kg of body weight, PO, q 12 h) for 35 days were compared with those of a control group of 6 dogs that were given gelatin capsules. Analyses were performed at 2-week intervals during and after prednisone administration. Lymphocyte and eosinophil counts were significantly (P less than 0.005) decreased after 2 and 4 weeks of prednisone treatment, compared with controls. Two weeks after treatment, eosinophil counts in prednisone-treated dogs were similar to those of control dogs, whereas lymphocyte counts remained low 4 weeks after treatment in treated dogs (1,869 +/- 145 cells/microliters), compared with that in control dogs (3,662 +/- 548 cells/microliters). Neutrophil and monocyte counts did not significantly change during glucocorticoid administration. Mean platelet volume significantly (P less than 0.001) decreased after 4 weeks of prednisone treatment, but returned to pretreatment values by 2 weeks after treatment. Four weeks of prednisone treatment did not cause significant increased activity in serum alanine transaminase, total alkaline phosphatase or the steroid-induced isoenzyme of alkaline phosphatase. Significant increases in serum albumin (P less than 0.001) and total protein (P less than 0.05) concentrations were detected after 4 weeks of treatment, but mean values were not significantly different from those of controls 2 weeks after treatment ended. Results of our study indicate that eosinophil and lymphocyte counts are the most sensitive indicators of long-term glucocorticoid administration at anti-inflammatory dosages of 1.1 mg/kg daily.

Septicemia in vaccinated and nonvaccinated turkeys inoculated with Pasteurella multocida serotype A:3,4.

Sixty-four, 10-week-old turkeys were inoculated with a highly virulent field isolate (86-1913) of Pasteurella multocida serotype A:3,4 by an oculo-nasal-oral route. Inoculated turkeys were examined at 4, 8, 16, 20, and 24 hours post-inoculation for bacteremia and histologic lesions. Bacteremia was detected in one of six turkeys 8 hours after inoculation and in four of six turkey poults at 16 hours post-inoculation. Pasteurella multocida was isolated from the spleens of two turkeys at 8 hours and from the spleens of all six poults 16 hours after inoculation. Peak concentrations of P. multocida reached 10(9) colony forming units per ml of blood. At 4 to 8 hours post-inoculation, isolate 86-1913 produced a fibrinopurulent bronchopneumonia followed by severe pulmonary necrosis, pleuritis, vasculitis; and, at 16 to 24 hours post-inoculation numerous extracellular bacteria were observed. Hepatic lesions included focal heterophil aggregates 8 hours after inoculation; these progressed to hepatic necrosis. Numerous extracellular bacteria within sinusoids were present 16 to 24 hours after inoculation. At 16 to 24 hours post-inoculation, there was degeneration of periarteriolar reticular cells in the spleen; these cells progressed to coalescing coagulative splenic necrosis with extracellular bacterial colonies. A second group of 41, 10-week-old turkeys, previously vaccinated with the Clemson University strain of P. multocida serotype A:3,4, were challenged with isolate 86-1913.(ABSTRACT TRUNCATED AT 250 WORDS)

The pathogenesis of Pasteurella multocida serotype A:3,4 infection in turkeys: a comparison of two vaccine strains and a field isolate.

The pathogenesis of avian pasteurellosis caused by two vaccine strains, M-9 and Clemson University (CU), and a highly virulent field isolate, 86-1913, of Pasteurella multocida (serotype A:3,4) was studied in 7-week-old turkeys inoculated by an oculo-nasal-oral technique. Turkeys inoculated with strain CU and isolate 86-1913 developed severe progressive bacteremia that began at 4 hours postinoculation (PI) and peaked at 16-20 hours PI. Turkeys inoculated with strain CU and isolate 86-1913 had significantly higher concentrations of bacteria in blood and tissues, and greater histologic lesion scores for necrosis, heterophil infiltrates, and intralesional bacteria than turkeys inoculated with strain M-9. Immunohistochemical staining specific for P. multocida demonstrated numerous extracellular bacteria in tissues from turkeys inoculated with strain CU and isolate 86-1913. The mortality for turkeys inoculated with isolate 86-1913 was significantly higher than for turkeys receiving the two vaccine strains.

A comparison of two methods of partial pancreatectomy in the dog.

Partial pancreatectomy was performed in 9 dogs by dissection and ligation of the pancreatic ductule and blood vessels, and in 10 dogs by a suture fracture technique. The dogs were evaluated for detrimental effects by (1) monitoring clinical signs and serum amylase and lipase activities and (2) examining the excision sites grossly and histologically at necropsy. There were no clinically apparent detrimental effects with either technique. The suture fracture technique evoked more histologic inflammation than the dissection and ligation technique.

Lymphangiosarcoma and haemangiosarcoma in a cat.

Ultrastructural findings in a feline ventral abdominal vascular tumour showed lack of basal lamina, few micropinocytotic vesicles and intercellular junctions and a discontinuous endothelial cell layer. A splenic cyst had a continuous basal lamina, numerous micropinocytotic vesicles and intercellular junctions and a continuous endothelial cell layer. These findings were compatible with diagnosis of lymphangiosarcoma (ventral abdomen and metastases) and haemangiosarcoma (splenic cyst).

Intermediate filament staining in the cytologic and histologic diagnosis of canine skin and soft tissue tumors.

Formalin-fixed histologic and acetone-fixed cytologic preparations from 87 surgically removed subcutaneous and soft tissue canine tumors were examined for immunoreactivity to cytokeratin, desmin, and vimentin. The avidin-biotin complex (ABC) technique demonstrated immunoreactivity in both preparations, but the intensity and specificity of the reactions were dependent on the primary antibody. Polyclonal antibodies to cytokeratin were more consistent in immunoreactivity than were polyclonal desmin or vimentin antibodies. The monoclonal antibody proved more satisfactory for demonstrating vimentin than the polyclonal antibody. Greater dilutions of primary antibodies may be used on cytologic preparations than on histologic sections. Evaluation of cytologic preparations may be inconclusive due to background staining, scant cellularity, or poor cytoplasmic preservation.