Monoclonal antibodies and microfluorimetry were used to determine the absolute number of B and T lymphocytes in the blood of bovine leukemia virus (BLV)-infected cows. The blood lymphocyte populations from BLV-infected cows were significantly higher than those from BLV-negative cows. The increase in the lymphocyte population in 3 BLV-infected nonlymphocytotic cows was attributed to a significant increase in the number of T lymphocytes; in 3 BLV-infected persistently lymphocytotic cows, the increase was attributed to a significant increase in the number of B and T lymphocytes. One persistently lymphocytotic cow had a high lymphocyte count, and lymphocytes from this cow contained cells that appeared to stain with markers specific for bovine B and T lymphocytes. We concluded that infection of cattle with the B-cell lymphotropic retrovirus, BLV, not only affected B cells, but also T cells.

One-day-old turkeys were inoculated intranasally with Bordetella avium. Noninoculated hatchmates were housed separately. At postinoculation weeks 1,2,3,4, and 5, B avium-infected (BA+) and B avium-free (BA-) turkeys were necropsied; specimens of tracheas, intrapulmonary primary bronchi, and lung adjacent to primary bronchi were bacteriologically cultured. Lung tissue was collected for histologic examination. Lungs perfused with acetic acid were collected for evaluation to determine the size, number, and distribution of lymphoid nodules associated with primary bronchi. Bordetella avium was isolated from trachea and primary bronchi of all BA+ turkeys, but was never isolated from lung parenchyma. Acute purulent bronchitis was associated with colonization of the primary bronchi by B avium from postinoculation weeks 1 to 3. Macrophages and lymphocytes persisted in the peribronchial connective tissue for 5 weeks after inoculation. Bronchus-associated lymphoid tissue consisted of discrete lymphoid nodules protruding into the lumens of primary bronchi. Lymphoid nodules, morphologically similar in BA+ and BA- turkeys, were composed of nonciliated, cuboidal epithelium covering a zone of loosely arranged lymphocytes and macrophages and a deeper, sharply demarcated lymphoid follicle. Compared with bronchus-associated lymphoid tissue of BA- turkeys, lymphoid nodules of bronchus-associated lymphoid tissue in BA+ turkeys were more numerous and widely distributed along primary bronchi. In both BA- and BA+ turkeys, the mean diameter of lymphoid nodules doubled between 1 and 5 weeks of age.

Nine 7-month-old Beagle dogs were inoculated with 200 third-stage larvae of Dirofilaria immitis. The development of cardiac disease secondary to heartworm infection was confirmed by thoracic radiography, echocardiography, and angiography with blood pressure measurements. The only indication of renal disease was mild-to-moderate proteinuria. The dogs were euthanatized approximately 18 months after inoculation. The mean microfilarial count in blood at the time of euthanasia was 88,700/ml, with a mean of 89 adult heartworms in the vena cavae, heart, and pulmonary arteries. The kidneys were perfused for microangiographic and correlative histologic examination of the intrarenal microvasculature and associated renal morphologic features. Angiograms of whole kidneys from 6 dogs revealed attenuation or truncation of the major renal vessels. Microangiograms of all kidney slices revealed attenuation in the microangiographic appearance of the glomerular capillaries. Histologic examination of all kidney slices revealed mild-to-intense, diffuse, chronic interstitial nephritis and generalized membranoproliferative glomerulonephritis. Microfilariae were observed within the glomerular capillaries and the medullary vessels. The microangiographic changes correlated with and were explained in part by the histologic changes in the renal parenchyma.

During a 1-year period, specimens were obtained monthly from 5 hair coat and 7 mucous membrane sites of 11 healthy dogs. Among 804 isolates of staphyloccocci, 13 species were identified. Staphylococcus intermedius was the most frequently isolated (40.2% of total isolates) coagulase-positive species, and S xylosus was the most frequently isolated (17.3%) coagulase-negative species. Moreover, S intermedius was the most frequently isolated species from the 12 sites evaluated and was isolated persistently from 8 of the 9 dogs that completed the 1-year study. On the basis of a commerical identification system, 14 profile numbers were identified for isolates of S intermedius. However, 2 profile numbers accounted for a majority (70.9%) of the isolates. Specific S intermedius biotypes identified on the basis of hemolysis, coagulase production, beta-lactamase activity, and antimicrobial susceptibility patterns were found repeatedly in 3 dogs. Seemingly, S intermedius was a resident of the normal bacterial microflora of these dogs; however, the inability to isolate S intermedius from 1 dog during the study year indicated that not all dogs habor S intermedius as a resident microorganism.

An index was developed to measure the proportion of intramammary infections caused by environmental microorganisms on dairy farms. This environmental index can be interpreted as the probability that an intramammary infection was caused by an environmental pathogen, rather than by a contagious pathogen. Using the environmental index as the outcome variable, risk factors for environmental mastitis were studied on 10 dairy farms in New York. Turning the cows outside was associated with lower environmental index, and having cows drink from a stream increased the environmental index. Selective (rather than uniform) nonlactating cow intramammary treatment was related to a lower environmental index (apparently because the farms practicing selective nonlactating cow treatment suffered from epizootics of contagious mastitis).

The minimum anesthetic dose (MAD) and the cardiopulmonary dose-response for halothane were determined in male chickens. The MAD for halothane was 0.85 +/- 0.09% (mean +/- SD), with a range of 0.75% to 0.98%. There was a significant (P less than 0.002) positive correlation between increasing concentrations of halothane and PaCO2, and significant negative correlations of halothane concentration with respiratory rate (P less than 0.04), arterial blood pH (P less than 0.008), and mean arterial blood pressure P less than 0.008). A significant correlation was not found between halothane concentration and heart rate or arterial blood bicarbonate concentration. It was concluded that the MAD for halothane in chickens is similar to values for minimum alveolar concentrations of halothane in mammalian species, and that there is substanial dose-dependent depression of cardiopulmonary function in chickens.

Three antigens were prepared from Pasteurella multocida strain P-1059, and their immunogenicity and antigenic relationships were investigated. The 3 antigens were a soluble antigen purified from a 2.5% NaCl extract (2.5S), a similar antigen purified from an extract in 0.3% formalin solution containing 0.85% NaCl (FS), and lipopolysaccharide (LPS). The antigens were treated with various chemicals and enzymes to study their antigenic and immunogenic determinants. Antigenic analyses with ELISA inhibition tests indicated that 2.5S and FS were similar LPS-protein complex antigens. The 2.5S and FS antigens induced protective immunity in turkeys with high antibody titers against LPS antigen. Although LPS was a component of 2.5S and FS,LPS itself was poorly immunogenic in turkeys. The antigenicity of protein compounds in 2.5S was deteriorated by protease treatment, which, however, did not significantly diminish the protective immunogenicity. Treatment of 2.5S with sodium periodate, altering its carbohydrate moieties, decreased its immunogenicity. The immunogenicity of 2.5S also was abolished by phenol-water treatment, owing to dissociation of the LPS-protein complex. These findings suggest that a certain form of LPS-protein complex is essential for the induction of immunity against the P multocida infection in turkeys.

The patency of mammary papillae was reestablished after surgically induced injury. Perforated prosthetic tubes with affixed Dacron tubing or Teflon strips were implanted in 18 abrabed papillae of lactating dairy cows and were secured with sutures. Wound healing was assessed by palpation and visual inspection. All wounds, with one exception, healed by first intention. Machine milking, reinstituted on day 5 after surgery, caused no apparent discomfort. Grossly and histopathologically, all implants stimulated a variable degree of mucosal metaplasia and hyperplasia. Only implants with Teflon strips became anchored by fibrotic invasion. Mastitis, tube migration, and milk fistulas were complications of the procedure.

A percutaneous biopsy technique for the study of endochondral bone formation in the dog was developed. With the dogs under general anesthesia or sedated with a combination of a tranquilizer and a local anesthetic, biopsy specimens were obtained from the proximal growth plate of the humerus with the use of a Jamshidi bone biopsy needle. Biopsy specimens were structurally intact, and contained epiphysis, growth plate, and metaphysis. The procedure proved to be a simple, safe technique, which caused minimal discomfort for the patient and did not affect the growth of the proximal end of the humerus, even after multiple biopsies.

Anthelmintic efficacies of fenbendazole, ivermectin, and levamisole were evaluated against naturally acquired infections of Nematodirus battus in lambs. Four groups of 10 lambs each were used. Oral administration of 8 mg of levamisole/kg of body weight or 5 mg of fenbendazole/kg significantly (P < 0.01) reduced the degree of infection by N battus (adults) by > 99%. An oral formulation of 200 microgram of ivermectin/kg was 98% effective (P < 0.01). Numbers of other Nematodirus spp (including N filicolis and N spathiger) were significantly reduced.