The effects of canine parvovirus (CPV) infection in dogs with hemolytic anemia was compared with the clinical effects of human parvovirus-induced aplastic anemia in human beings with chronic regenerative anemias. Phenylhydrazine was used to induce a transient, severe, hemolytic anemia in dogs to evaluate the effects of CPV infection on rapidly dividing bone marrow precursors. Erythrocyte colony-forming unit bone marrow cultures and cytologic examination of bone marrow were used to determine the effects of CPV infection on erythroid bone marrow precursors. The induced hemolytic anemia regenerated rapidly and although the bone marrow was infected, it was determined that CPV infection did not induce a detectable decrease in erythroid progenitors in dogs with severe hemolytic anemia.

Uveitis was induced in dogs by intracameral injection of canine lens protein. The lipoxygenase inhibitors phenidone and norhydroguaiaretic acid, and dimethyl sulfoxide decreased fibrin production at 0.5 and 1 hour after induction uveitis. Phenidone and norhydroguaiaretic acid also inhibited the initial increase intraocular pressure early in the course of inflammation. Leukotriene B4 in the aqueous was measured by use of radioimmunoassay at 1 hour after inflammation. In control dogs, 230 to 1,700 pg of leukotriene B4/ml was measured; in dogs treated with phenidone, leukotriene, B4 was not measured.

Hypophosphatemia was induced in 2 cows by reducing phosphorus content in their feed after parturition. Serum inorganic phosphorus (Pi) values decreased to 1 mg/dl within 10 days after parturition; and RBC adenosine 5'-triphosphate (ATP) and reduced glutathione values decreased to 50 and 70% of baseline values, respectively. Methemoglobin concentration was moderately higher than normal. These changes preceded the onset of hemolysis, and anemia progressed with decreases in PCV, hemoglobin concentration, and RBC counts. Serum Pi resumed its normal value when anemia was most severe. This RBC disorder was confirmed to be characteristic of hemolytic anemia in cows resulting from hypophosphatemia. The RBC glycolytic intermediates, totaal trisoe phosphate (combined glyceraldehyde-3-phosphate and dihydroxyacetone phosphate content) and fructose-1, 6-diphosphate, greatly increased in vivo and in vitro with decreases in serum or plasma Pi and RBC ATP. From our results, we concluded that inadequate Pi in the plasma impairs the function and viability of RBC by hindering the production of ATP via disturbance of reactions at the glyceraldehyde-3-phosphate dehydrogenase step.

Gastric emptying of a radionuclide-labeled test meal was studied in 10 dogs that had been treated surgically for gastric dilatation-volvulus and in 10 clinically normal (control) dogs. There were no significant differences between the gastric emptying rates and patterns in treated and in control dogs. Thus, there are no indications that gastric emptying is delayed in dogs that have recovered from gastric dilatation-volvulus, and there is no reason for pyloric surgery in dogs with this condition.

The role of turkey complement in a serum bactericidal reaction was determined using serum-sensitive and serum resistant Escherichia coli isolated from turkeys. Inactivation of complement by heating serum (56 C for 40 minutes) or by treating serum with 10mM EDTA eliminated bactericidal activity. Serum sensitive E coli organisms were killed by turkey serum treated with 10 mM ethylene glycol-bis-beta-(aminoethyl ether)-N, N, N,' N,'-tetraacetic acid and 5 mM MgCl2. Exposure of normal turkey serum to serum-sensitive or serum resistant E coli resulted in equivalent reductions in hemolytic activity of serum. Treatment of serum-resistant E coli with antibody rendered the bacteria sensitive to bactericidal effects of normal turkey serum. Serum-sensitive E coli organisms were readily killed by an alternative complement pathway, serum-sensitive and serum-resistant E coli activated the complement system equally well, and antibody was required for complement-mediated killing of certain serum-resistant E coli organisms from turkeys.

Serum and vaginal Brucella-specific immunoglobulin isotypes (IgGl, IgG2, IgM, and IgA), obtained from 62 crossbred beef heifers vaccinated with Brucella abortus salt-extractable proteins and subsquently challenge exposed with B abortus S2308, were studied. Brucella-specific IgG antibodies and Brucella-specific immunoglobulin isotypes were quantitated by a fluorometric immunoassay. Serum and vaginal immunoglobulin responses were evaluated as a method of distinguishing infected from noninfected heifers. Rivanol precipitation, complement-fixation, buffered-antigen brucellosis tests and an ELISA were performed on sera. For immunoglobulin isotypes, vaccinated heifers had mean antibody responses higher than baseline mean antibody responses for at least 31 weeks after vaccination. After challenge exposure, significant differences (P > 0.05) were not detected between mean antibody responses of vaccinated and nonvaccinated heifers. Vaginal Brucella-specific antibody responses did not correlate with protection from disease. Vaginal Brucella-specific IgM was detected only at the time of abortion.

The efficacy of ivermectin as an in-feed formulation was evaluated against naturally acquired gastrointestinal helmiths, lungworms, and sarcoptic mites (experiment 1; n = 24) and against induced infection with intestinal nematodes (experiment 2; n = 24) in pigs. Treatments consisted of ivermectin administered in feed at concentrations calculated to provide 100 or 200 microgram/kg of body weight/d for 7 days or of nonmedicated feed (controls) for 7 days. At concentration of 100 microgram of ivermectin/kg/d, efficacy against naturally acquired infections was 97.7% for Ascaris suum, 97.8% for Metastrongylus spp, greater than 99% for Oesophagostomum spp, 100% for Macracanthorhynchus hirudinaceus, and 89.7% for Ascarops strongylina. Against induced infections (fourth-stage larvae), efficacy was 100% for A suum and 96.9% for Oesophagostomum spp. At concentration of 200 microgram of ivermectin/kg/d, efficacy against naturally acquired infections was 100% for A suum, Hyostrongylus rubidus, Metastrongylus spp; and 85.9% for Macracanthorhynchus hirudinaceus. Against induced infection (fourth-stage larvae), efficacy was 100% for A suum and 95% for Oesophagostomum spp. At concentrations of 100 and 200 microgram of ivermectin/kg/d, efficacy against Sarcoptes scabiei var suis was evidenced by elimination of the mite by posttreatment day 14.

Six groups of 5 dogs each were fed dilutions of canine adenovirus-2, either as raw liquid or after insertion into cornmeal baits. By the fourth week after vaccination, 29 of the 30 dogs developed high titers of serum-neutralizing antibodies to the virus.

Functional capabilities of morphologically mature (segmented) and immature granulocytes (neutrophils and eosinophils) from bone marrow from cows were studied and compared with similar activities of segmented granulocytes from blood. Phagocytosis of Escherichia coli and postphagocytic oxidative metabolic stimulation, measured by nitroblue tetrazolium (NBT) reduction, were evaluated simultaneously. Phagocytosis was observed readily in segmented neutrophils, neutrophilic bands, and metamyelocytes and rarely in myelocytes. Phagocytosis was not seen in promyelocytes and myeloblasts. Neutrophilic bands and metamyelocytes were phagocytically less active than were segmented neutrophils. Washed segmented bone marrow neutrophils possessed phagocytic activity similar to that of blood neutrophils, whereas the activity of unwashed segmented bone marrow neutrophils was markedly less than that of blood neutrophils. Reduction of NBT was observed only in blood segmented neutrophils and bone marrow segmented neutrophils; the magnitude of NBT reduction was significantly (P = less than 0.005) less in bone marrow neutrophils than in blood neutrophils. Eosinophils were phagocytically less competent than were neutrophils. The NBT reduction was observed only in eosinophils from blood, but not in eosinophils from bone marrow.

The use of cultured tissue has not yet become wide-spread in research involving equine disease, and this may be attributable in part to the scarcity of published reports concerning tissue culture methods for this species. We report here the isolation of equine microvascular endothelium (EMVE) from fresh omental tissue of horses and ponies. Fresh donor tissue was minced, subjected to collagenase digestion, and filtered. Cells were layered on 5% bovine serum albumin for gravity sedimentation, the bottom layer was collected, and the cells were plated onto fibronectin-coated flasks. Medium consisted of Dulbecco modified Eagle medium with 10% whole fetal bovine serum (wFBS) and 20 micrograms of endothelial cell growth supplement/ml. The EMVE grew readily in culture, had the cobble-stone morphologic feature at confluence, stained positively for factor VIII-related antigen, and metabolized acetylated low-density lipoprotein. Fibroblast and smooth muscle cell contamination was minimal in primary cell cultures, which were successfully passed and maintained in culture for 3 to 5 serial passages, using various media and substrates. Preliminary studies were undertaken to determine optimal growth conditions with a range of variables: serum concentration, extracellular matrix components, and growth factors. Optimal conditions were achieved with a minimum of 10% wFBS, and with either fibronectin or laminin as extracellular matrix substrates. The EMVE grew adequately in Dulbecco modified Eagle medium plus 10% wFBS, and the added growth factors or serum supplements did not appear necessary for growth of EMVE.