Milk-flow, ultrasonographic, theloscopic, and histopathological characteristics of the teat in cows with toxic mastitis.

The milk-flow, imaging, and histopathological characteristics of the teat in five cows with toxic mastitis were investigated. Teats were grouped into type I (without gross and histopathological abnormality), type II (no abnormal gross findings, but with histopathological abnormality), and type III (with gross and histopathological abnormality). Normal teats from six cows served as controls. Type II and III teats had lower milk-flow, compared with the controls. Ultrasonography revealed no abnormal findings, except for irregular mucosal surface in type II teats and absence of hyperechoic line along the teat canal in type III teats. The theloscopic findings varied from normal to mucosal abnormalities in type II and III teats. Histopathology demonstrated epithelial changes, congestion, hemorrhage, edema, cellular infiltration, and elastic fiber degradation in type II and III teats, with the type III teats showing severe changes. Toxic mastitis was characterized by impaired milk-flow and various degrees of imaging and histopathological abnormality.

Effect of intravenous infusion of a 7.2% hypertonic saline solution on serum electrolytes and osmotic pressure in healthy beagles.

The effect of an intravenous (i.v.) infusion of hypertonic saline solution (HSS; 7.2%, 2,400 mOsmol/kg.H2O) was evaluated by serum electrolyte concentrations and osmotic pressure in the anesthetized beagles. Sixteen beagles were assigned to 3 experimental groups (2.5, 5 or 15 ml/kg of HSS i.v. infusion) or a control group (5 ml/kg of isotonic saline solution (ISS) i.v. infusion) and were monitored for 120 min after the initiation of fluid infusion. The relative plasma volume (rPV) in the 5 ml/kg and 15 ml/kg HSS groups progressively expanded to 143.1 +/- 7.4% at 3 min and 156.4 +/- 5.9% at 5 min after the initiation of the fluid infusion, respectively. Significant increases were not produced by ISS and 2.5 ml/kg HSS infusion. The serum sodium and chloride concentrations in the ISS group were not altered. The 5 ml/kg HSS infusion induced transient high osmotic and sodium levels, and the serum sodium concentration remained under the 160 mM/l after the completion of the HSS infusion. However, the 15 ml/kg HSS infusion induced a constant high osmotic level (340.5-352.8 mOsmol/kg.H2O) and hypernatremia (161.4-174.5 mM/l) from 10 to 90 min after the initiation of the fluid infusion. The 15 ml/kg HSS infusion induced significant decreases in the partial pressure of oxygen (PaO2), reaching 63.7 +/- 8.0 mmHg at 120 min after the initiation of the fluid infusion compared with an immediately before fluid infusion value. On the basis of these findings, 5 ml/kg HSS infusion can be safely administered to healthy beagles for expanding the plasma volume without inducing hypernatremia. A 5 ml/kg HSS infusion is thus recommended for the initial field resuscitation of dogs.

Effect of a 7.2% hypertonic saline solution infusion on arterial blood pressure, serum sodium concentration and osmotic pressure in normovolemic heifers.

The effects of an intravenous (i.v.) infusion of a small volume (5 ml/kg) or large volume (15 ml/kg) of hypertonic saline solution (HSS; 7.2%, 2,400 mOsmol/kg.H2O) and those of an i.v. infusion of 5 ml/kg isotonic saline solution (ISS; 300 mOsmol/kg.H2O) on plasma volume, arterial blood pressure, serum sodium concentrations and osmotic pressure were investigated in conscious heifers. Nine heifers (3 heifers/group) were monitored for 120 min after the initiation of fluid replacement. The relative plasma volume (rPV) in the 5 ml/kg HSS and 15 ml/kg HSS progressively increased to 137.7 +/- 2.4% at t = 5 min and 145.2 +/- 5.4% at t = 15 min, respectively. The expanding plasma volume in the 5 ml/kg HSS group remained at an up to 10% higher level until 120 min, but not in the 15 ml/kg HSS group. The 5 ml/kg HSS infusion induced transit high-osmotic (305.3 +/- 4.0 mOsmol/kg.H2O) and sodium levels (155.7 +/- 3.5 mM/l) at t = 5 min. However, the 15 ml/kg HSS infusion induced constant high-osmotic level (321.7-336.7 mOsmol/kg.H2O) and hypernatremia (162.8-170.0 mM/l) from t = 10 min to the rest of the experiment period. In the ISS and 5 ml/kg HSS groups, no changes in PaO2 were observed. The 15 ml/kg HSS infusion induced a significant decrease in the partial pressure of oxygen at the t = 30 min compared to the t = 0 min values. On the basis of these findings, a small volume (5 ml/kg) HSS infusion can be rapidly and safely administered to cattle for expanding the plasma volume without inducing hypernatremia. A 5 ml/kg HSS infusion is thus recommended for the initial field resuscitation of cattle.

Effect of infusion of hypertonic saline solution of conscious heifers with hypoxemia caused by endotoxin infusion.

OBJECTIVE: To compare effects of i.v. infusion of a small volume (5 ml/kg of body weight) of hypertonic saline (7.2% NaCl) solution (HSS) and i.v. infusion of an equivalent volume of isotonic saline (0.9% NaCl) solution (ISS) on arterial blood gases in conscious heifers with hypoxemia caused by endotoxin infusion. ANIMALS: 9 Holstein heifers. PROCEDURE: All heifers received 2.0 microg of endotoxin/kg, i.v., during a 5-minute period. Twenty-five minutes after endotoxin infusion, 3 heifers received ISS, 3 received HSS, and the remaining 3 did not receive fluids (control). Heifers were monitored for 150 minutes after initiation of fluid replacement. Arterial blood gases, blood pressure, and serum electrolyte concentrations were measured. RESULTS: Endotoxin administration had a profound effect on pulmonary function, causing severe hypoxemia accompanied by a significant decrease in the partial pressure of oxygen (PaO2) and a significant increase in the arterial-alveolar O2 gradient (P[A-a]O2). Cattle in the HSS group had progressive and significant increases in PaO2 and O2 saturation, compared with the other groups. The P(A-a)O2 values for the control and ISS groups were slightly decreased until 150 minutes after initiation of fluid replacement; however, HSS infusion induced a progressive and significant decrease in P(A-a)O2 for the remainder of the experimental period. CONCLUSIONS AND CLINICAL RELEVANCE: Rapid infusion of HSS can successfully resuscitate conscious cattle with induced pulmonary dysfunction. Infusion of HSS may be beneficial for initial resuscitation of cattle with naturally developing bovine respiratory disease complex.

Comparison of commercial isotonic fluids intravenously administered to rehydrate fasted bullocks.

Holstein bullocks were used in this study to compare the effectiveness of five commercial parenteral fluids (saline IS, Hartmann's IH, 5%-glucose 5G, Ringers IR, and 1/2 Ringer's and 2.5% glucose combination solutions RG) in correcting the disturbances associated with dehydration induced by fasting for 48 hr. These five commercial fluids (30 ml/kg) were given to bullocks with dehydration induced by fasting for 48 hr. Arterial and venous blood samples were taken before fasting, and at 0, 15, 30, 45, 60, 90, 120, 240, 360 min, and 24 hr after initiation of fluid administration. Fasting for 48 hr induced significant reductions in body weight and relative plasma volume (rPV), of approximately 7.72 and 21.93%, respectively. During the administration period, rPV showed a progressive increase from approximately 88.1% after fasting to 113.0% with no significantly differences between groups. A rapid decrease of rPV when fluid administration has been finished was observed in the 5G and RG groups. The results of the fluid administration trial showed that the 1/2 Ringer's and 2.5% glucose combination solution inhibited the acidification of the blood, produced no change in the electrolyte balance of serum, and induced a proper reabsorption rate of glucose in the renals, and was therefore considered the best choice for the rehydration of adult cattle which have had no appetite for over 2 days.

Further analysis of the phenotype and distribution of tumor cells in sporadic B-cell and T-cell lymphomas in the lymph node and spleen of cattle.

Immunohistologic studies were performed to identify the phenotype and distribution of neoplastic lymphocytes in the spleens of BLV-negative animals examined by PCR and diagnosed as having sporadic bovine leukosis. Tumor cells from three cases of sporadic bovine leukosis were identified as of B-cell lineage. Tumor cells from three additional cattle were identified as CD3+ CD4- CD8+, CD3+ CD4- CD8-, and CD3+ CD4- WC1+, respectively. The last case was diagnosed as a gamma/delta T-cell lymphoma. Differences in morphology proliferative characteristics were recognized between B- and T-cell type lymphomas. The tumor cells in B-cell type lymphoma were characterized as follows: medium or large in size, round or polymorphic nucleus with rough chromatin with some tumor cells containing a convoluted nucleus. These tumor cells of B-cell type lymphoma were present in the red pulp and periarteriolar lymphoid sheath. Tumor cells of the T-cell type lymphoma were uniformly smaller than B-cell type and present around arteries or replaced red pulp of the spleen.

Protective efficacy of an affinity-purified hemolysin vaccine against experimental swine pleuropneumonia.

Protective efficacy of Actinobacillus pleuropneumoniae extracellular hemolytic toxins, RTX-toxin I (Apx I) and Apx II, was evaluated in pigs. The hemolysins were purified from culture supernatant of A. pleuropneumoniae strain HA-337, serotype 1 by immunoaffinity chromatography using a monoclonal antibody specific for Apx I or Apx II as ligand. Four pigs were vaccinated with the purified hemolysins absorbed on aluminum phosphate gel adjuvant. Four pigs of a control group were given placebo. Hemolysin-neutralizing antibodies were detected only in vaccinated group after booster injection. One of four control pigs died following an aerosol challenge with the homologous strain, and three surviving pigs developed serious clinical signs of pneumonia and had extensive lung lesions. In contrast, there was no mortality in vaccinated group. Only transient hyperthermia was observed in two vaccinated pigs after challenge. A necropsy, two vaccinated pigs had slight localized pulmonary lesions, though the remaining two had no lung lesions at all. These results indicate that the hemolysin vaccine made of Apx I and Apx II has good protective activity against swine pleuropneumonia caused by A. pleuropneumoniae serotype.

Immunohistological evaluation on respiratory lesions of pigs intranasally inoculated with Actinobacillus pleuropneumoniae serotype 1.

Nine-week-old pigs were inoculated intranasally with 6.10 X 10(3) (group 10(3)), 10(5) (group 10(5)) and 10(7) (group 10(7)) colony-forming unit of Actinobacillus pleuropneumoniae (App) serotype 1 designated HA-337 strain, respectively. One pig in group 10(5) and 2 pigs in group 10(7) died with dispnea and hemorrhagic pleuropneumonia within 20 to 48 hr post inoculation (PI). All pigs necropsied on 7 days in groups 10(5) and 10(7) had focal fibrous pleuropneumonia. Histologically, pulmonary lesions were classified into three stages; peracute, acute and subacute. Fatal cases in group 10(7) had peracute lesion composed of severe edema, hemorrhage and necrobiosis of alveoli, with mononuclear cells infiltration in the dilated interlobulus. The fatal case in group 10(5) had acute pulmonary lesion composed of focal or linear infiltration of round and fusiform cells that frequently showed swirling pattern in alveoli. The surviving cases in group 10(5) and 10(7) had subacute lesion composed of multifocal pulmonary necrosis surrounded by fibrous tissue. The swirling pattern was clearly seen in demarcation zone. Immunohistochemically, App antigens scattered as intact bacteria in alveoli, dilated interlobular septa and pleura, and lymph vessels in peracute and acute lesions. Areas of necrosis were also stained weakly. Although no antigen was detected in cytoplasm of macrophages and infiltrated cells in peracute lesions, App antigen was detected as positively stained mass in cytoplasm of some macrophages in acute lesions. In subacute lesions, App antigens were recognized as intact bacteria in necrotic areas and among the swirling pattern cells of demarcation zone. Macrophages had App antigens as a large mass of pigment in the cytoplasm in area of fibrosis.

Phenotypic analysis of neoplastic cells from calf, thymic, and intermediate forms of bovine leukosis.

Immunohistochemistry and flow cytometric analysis were used with monoclonal antibodies to examine the phenotype of neoplastic cells from cattle with sporadic bovine leukosis (three cases of calf form, two cases of thymic form, and three cases of intermediate form). Three cases of calf form and two cases of intermediate form were positive for B cell lineage in immunohistologic examination and in flow cytometric analysis for B-B2+, sIgM+, and major histocompatibility class II+. Two cases of thymic form and one case of intermediate form were CD2+, CD5+, CD6+, and CD8+ in immunohistologic examination and in flow cytometric analysis. The results show that neoplastic cells develop from B and T cell lineages in sporadic bovine leukosis.

Immunohistologic studies on subpopulations of lymphocytes in cattle with enzootic bovine leukosis.

The distribution of subpopulations of lymphocytes in lymph nodes and tumors from cattle with enzootic bovine leukosis (EBL) was examined by immunohistochemistry using a panel of monclonal antibodies against leukocyte differentiation molecules of EBL. The lesions in lymph nodes could be divided into three types based on the extent of infiltration and proliferation of neoplastic cells with provirus and differential expression of leukocyte differentiation molecules. The number of B-B2+, sIgM+ cells was reduced in frequency in follicles during the neoplastic cell proliferation. CD4- and CD8-positive alpha/beta T cells and gamma/delta T cells positive for WC1 (workshop cluster designation) were also reduced in frequency in areas infiltrated with neoplastic cells. Almost all neoplastic cells were B-B2- and IgM-positive. However, there were a few B-B2- and/or IgM-negative cells or cells stained faintly in all cases. WC1+ cells were not observed in tumor tissues. However, CD4+ and CD8+ cells were observed throughout tumor tissues, suggesting a role for these cells in tumor immunity.

An immunohistochemical study of an equine B-cell lymphoma.

The tissues of an 8-year-old thoroughbred castrated male horse with equine lymphoma were examined immunohistochemically. Neoplastic masses were observed in the mediastinum, mesenteric lymph nodes, gastric mucosa and serosa, liver capsule, and spleen capsule with associated lymph nodes. Histopathologically, the neoplastic cells were seen to consist predominantly of a mixture of well differentiated small and large types. Immunohistochemically, the small lymphoid cells were MHC class IIlow+ and PanT- and the large lymphoid cells were MHC class IIhigh+ and PanT-. These findings revealed that the neoplastic cells were of B-lymphocyte lineage.

Phenotype analysis of lymphocytes present in different stages of neoplasia induced by bovine leukemia virus.

Distribution of subpopulations of lymphocytes in the lymph nodes and tumor tissues from cattle with enzootic bovine leukosis (EBL) was examined by immunohistology using a panel of monoclonal antibodies against leukocyte differentiation molecules of bovine leukocytes and tumor-associated antigen (TAA) of EBL. As disease progressed in the lymph nodes, TAA positive cells increased in number and were strongly positive. The number of B-B2, IgM positive cells were reduced in frequency in the follicle and areas of neoplastic cell-proliferation. Alpha beta and gamma delta T cells positive for WC1 (workshop cluster designation) were reduced in frequency due to infiltration and proliferation of neoplastic cells. In tumor tissues which were thought to consist with monoclonal population of cells carrying BLV provirus, strongly TAA-positive cells were present throughout the section. Most of the neoplastic cells from five cattle with EBL appeared to be divided into four types, CD2-, CD4-, CD8-, WC1-, B2+ or B2-, IgM+ or IgM-, MHC II+ and strong TAA+. WC1+ cells played no apparent role in the development of lymphosarcoma of EBL. WC1+ cells were not observed in tumor tissues. However, the possibility of effect of T cell for tumor immunity was suggested, since TH/l and Tc/s cells were scattered in the tumor tissues.

Twenty cases of equine osteoarthrosis detected at autopsy.

A pathological study was performed on osteoarthrosis detected at autopsy in 20 horses whose ages ranged from 21 days to 17 years old. They were asymptomatic on the joints except in 3 animals, and autopsied after death or sacrificed due to accidental fracture or other diseases. Lesions of osteoarthrosis were recognized in all horses, which tended to increase in incidence and severity according to age. Lesions were concentrated at hinged joints such as the elbow, fetlock, and hock. Synovial fossae and ulcerative lesions were observed on each opposite articular cartilage, forming the so-called mirror image. Linear erosions regarded as a secondary one were frequently observed on the cartilages. Histologically, the lesions were classified into 4 phases, 1) edematous degeneration, 2) crevice formation, focal necrosis, erosion of cartilage, 3) ulcerative changes, 4) regenerative changes of cartilage in foals and proliferation of fibrous or adipose tissue on the denuded subchondral bone in aged horses. By toluidine blue stain, decreased acid mucopolysaccharide was suggested in cartilaginous matrix around the lesions. From the results, it was concluded that the disease was a disorder of articular cartilage accompanied with hypoplasia of articular subchondral bone.