The purpose of this project was to study the effect of superalimentation in lactating sows through permanent, surgically placed, gastric cannulas. A surgical technique was developed to install gastric cannulas into pregnant sows to allow superalimentation by introducing feed through the cannula. After induction of general anesthesia, a flexible, T-shaped cannula (22 mm outside diameter) was surgically placed in the dorsal portion of the greater curvature of the stomach and exteriorized through the tenth intercostal space approximately 30 cm left of the dorsal midline. Cannulas were installed on day 85 5 days of gestation. Anesthesia, surgical procedures, and the subsequent presence of the cannula did not affect the size ornumber of live pigs at birth. In addition, the prevalence of stillbirths and mummified fetuses was not significantly different than that of noncannulated sows. The gastric cannulas did not affect lactation performance, as litter size and weight were unaffected when compared with that in noncannulated controls. Postmortem examination of euthanatized sows revealed adhesions of the gastric wall to the abdominal wall, thus eliminating the possibility of leakage of the gastric contents into the peritoneum. Detrimental effects of the cannulas on gastric function or capacity were not detected, and cannulas could be maintained through multiple parities.

Experimental pneumonia caused by Pasteurella haemolytica was induced in 2-week-old gnotobiotic (n = 4) and conventional (n = 6) calves by endobronchial inoculation into the right caudal lung lobe of 7.9 X 10(10) +/- 0.6 X 10(10) (mean +/- SD) colony-forming units of P haemolytica in the 6-hour log phase of growth. The calves were studied for 24 hours or less. Regression lines for the relationship between clinical index and time for the gnotobiotic group and conventional group of calves were compared, and the clinical index was found to be significantly (P less than or equal to 0.005) more rapid in the gnotobiotic group. There was also a significant difference in the preinoculation, absolute segmented neutrophil count (P less than or equal to 0.05), and in the total serum protein, albumin, and globulin values (P less than or equal to 0.05). Comparison of the preinoculation and post inoculation blood cell and blood chemical values revealed a significant increase (P less than or equal to 0.05) in the numbers of band neutrophils and fibrinogen in conventional calves, and a significant decrease (P less than or equal to 0.05) in the total WBC count in gnotobiotic calves. Necropsy of both groups of calves revealed a circular to oblong lesion that was congested, edematous, and firm, and which occupied 20% to 100% of the right caudal lung lobe and involved the remaining lung lobes to a more minor degree. When mean lesion scores of the 2 groups of calves were compared, no significant difference (P less than or equal to 0.05) was found. Microscopic examination of the lungs revealed edema of the perivascular and interlobular septa and hemorrhage in the alveoli of both groups, although the conventional group had more fibrinopurulent inflammation.

High-performance liquid chromatography (HPLC) was used to determine the phospholipid (PL) composition of ovine, equine, bovine, porcine, and canine RBC membranes. Procedural modifications of established techniques provided for separation of 7 PL within a 15- to 20-minute sample run. Significant (P < 0.05) differences were detected in RBC membrane PL composition among the various species. The concern for physiologic properties associated with hemolysis and/or sedimentation rate must include evaluation of differences in the PL bilayer structure.

A study was made to determine the effect of Haemonchus contortus parasitic infection in lambs on the clearance of several IV administered drugs. Clearance of sulfobromophthalein or sulfathiazole from the plasma of lambs was unaffected by infection with H contortus. Clearance of antipyrine was enhanced by the infection, and thiabendazole treatment did not alter this effect. Clearance of chloramphenicol (CAP), administered as the succinate ester (CAPS), was not changed by the infection, but it was increased after treatment with thiabendazole. Changes in the mean body residence time and initial plasma concentration of CAPS and CAP after treatment with thiabendazole indicate that hydrolysis of CAPS to CAP was reduced. High concentrations of CAPS apparently enhanced its own elimination directly rather than via the expected sequence involving hydrolysis, glucuronidation, and excretion of CAP-glucuronide. Enhanced clearance of antipyrine following infection of lambs with H contortus can be explained in at least 2 ways. First, it is possible that thelambs did not have mature amounts of hepatic drug metabolizing enzyme activity as reported by other investigators, which may be explained by breed differences or animal husbandry practices. Second, infection of lambs by H contortus may have triggered an inductive response in hepatic cytochrome P-450-mediated activities, which might result via a generalized enhancement in hepatic protein synthesis associated with the physiologic response to replace plasma proteins and other blood components lost through gastrointestinal hemorrhage caused by the active feeding of adult worms. Other phase-II reactions such as acetylation, glucuronidation, and glutathione-S-transferase apparently were not affected.

Absorption rate and plasma and fat disposition oflindane after various lindane percutaneous treatments in shorn and unshorn sheep were investigated. To analyze data with a deconvolution method, IV administration was performed to determine the basic pharmacokinetic values of lindane in sheep. After IV administration, the steady state volume of distribution was very high (8.07 +/- 3.60 L/kg of body weight), and the mean residence time was long (28.1 +/- 11.7 hours). Deconvolution analysis indicated that lindane absorption was continuous until 33 to 41 days after spraying with a 0.025% lindane solution. Total amount of absorbed lindane in shorn (15,171 +/- 4,463 microgram/kg) sheep was about twice that in unshorn (7,615 +/- 3,128 microgram/kg) sheep; from deconvolution analysis, it was calculated that the time required for 50% of the available dose to be absorbed was between 115 and 179 hours. After percutaneous lindane administration, the fat concentration was compared with the available lindane dose. The apparent half-life of lindane elimination in fat was 225 +/- 47.4 hours, which is similar to the value calculated for the absorption rate constant. By comparing fat and plasma concentrations, it was calculated that for a mean plasma concentration of 5 ng/ml, the fat lindane concentration was 1.65 +/- 0.87 microgram/g (ie, lower than the generally accepted tolerance level of 2 microgram/g).

The activity of leukocytes, determined by chemiluminescence (CL) emission, was compared with the somatic cell count (SCC) in 4,883 quarter-milk samples from 132 dairy cows. The presence of bacteria was determined by bacteriologic culture of samples in which SCC and CL were high. Chemiluminescence was measured with an automated illuminometer system at 37 C after separating the leukocytes from milk by allowing them to adhere to cotton-wool swabs. Chemiluminescence emission was induced by opsonized zymosan and enhanced by luminol. After luminol and zymosan were added to the measuring vials containing the swabs, CL emission increased rapidly, reaching its maximum usually at about 15 minutes of reaction time, and decreasing slowly thereafter. In general, good correlation was found between CL and SCC (r = 0.876; P less than or equal to 0.001; n = 4,883). Even milk samples with low SCC gave reliably measurable CL signals. Minor pathogens in the milk caused about a sevenfold increase in both SCC and CL, whereas major pathogens caused 14- and 25-fold increases in SCC and CL, respectively. The diagnostic situation that requires both sensitivity and specificity to be at least 90% was attained only by the CL assay for major pathogens. These results suggest that the measurement of milk leukocyte activity by CL assay applies well to the diagnosis of mastitis, and has the potential to become a large-scale laboratory test, as well as a simple cowside test.

A mucosal lesion was created in the center of each test sinus of 6 mature, healthy, nonlactating Holstein cows by resecting a circumferential band of mucosa. Each lesion was then treated by implantation of strip grafts of autogenous oral mucosa, temporary silastic tube implant, or a combination of strip grafts and temporary silastic tube implant. All teats were evaluated for patency 6 weeks after treatment, and tube implants were removed through a second thelotomy incision. All teats were reevaluated for gross and radiographic patency 12 weeks after treatment, and teats were collected for histologic evaluation of lesions. All 4 teats treated with grafts only were obstructed at 6 and 12 weeks after treatment. Incomplete coverage of the lesion with mucosa was observed in all 4 teats. The major source of obstruction was proliferation of epithelium and keratin into the lumen. All 8 teats treated with temporary silastic tube implants alone were patent at 6 weeks after treatment, but were obstructed at 12 weeks after treatment. Foci of mucosa at the lesion site were detected in only 2 of the 8 teats. Obstruction resulted from proliferation of granulation tissue into the lumen. All 12 teats treated with grafts and a temporary tube implant were patent at 6 weeks after treatment and 11 of 12 were patent at 12 weeks after treatment, although marked luminal narrowing was evident in 9 of 11 teats. Partial to complete coverage of the lesion with mucosa was seen in all teats. Proliferative granulation tissue, epithelium, and keratin contributed to luminal narrowing in 10 of 11 patent teats. Bacteriologic culture of quarters from 6 of the 11 teats patent at the final evaluation yielded pathogens.

During the first part of a study, cats were inoculated with Cryptococcus neoformans via the following routes: intradermal, intranasal, IV, and intracisternal. Only use of the IV route of inoculation consistently induced disseminated cryptococcosis. In the second part of the study, disseminated cryptococcosis was experimentally induced in cats via IV inoculation of C neoformans. One month after inoculation, 3 cats were treated with ketoconazole (10 mg/kg of body weight/d) and 3 cats were treated with itraconazole (10 mg/kg/d) for 3 months. One of the ketoconzole-treated and 2 of the itraconazole-treated cats also had cryptococcosis of the CNS when treatment was begun. During treatment, serum cryptococcal antigen titer progressively decreased in all cats. Abnormalities in CBC values or the serum biochemical profile were not found in any cat during treatment. However, all ketoconazole-treated cats became anorectic and lost weight. Side effects were not seen in itraconazole-treated cats. During the 3-month posttreatment observation period, all cats remained healthy. At necropsy, histologic evidence of cryptococcosis was not found in the 3 ketoconazole-treated cats or in 2 of the itraconazole-treated cats. In the third itraconazole-treated cat, cryptococcal organisms were found in the kidneys.

The development of Anaplasma marginale was studied in Dermacentor andersoni nymphs after they had fed on a calf with ascending Anaplasma infection. Gut tissues were collected on day 4 of tick feeding, from newly replete (fed) nymphs and on postfeeding days (PFD) 5, 10, 15, 20, and were processed for light and electron microscopy to determine density of A marginale colonies. Homogenates of gut tissues were prepared from nymphs collected on the same days and inoculated into susceptible, splenectomized calves to test for infectivity. Anaplasma colonies were detected in gut cells on PFD 5, 10, 15, and 20. Although colony density appeared to be higher on PFD 10 and 15, differences were not significant. Nymphal type-1 colonies were detected in highest numbers on PFD 5 and 10, transitional colonies were seen in highest numbers at PFD 10 and 15, and nymphal type-2 colonies were observed only on PFD 20. Gut homogenates that were collected from ticks at 4 days of feeding, when newly replete, and on PFD 20 caused anaplasmosis when injected into susceptible calves, but homogenates made from ticks collected on PFD 5, 10, and 15 were not infective. The data indicate that of the colony types of A marginale that develop in replete nymphs, nymphal type-1 and transitional colonies may contain organisms that are not infective for cattle.

This work was an attempt to develop an in vitro adherence model for Mycoplasma hyopneumoniae, using monolayers of human and porcine lung fibroblasts and porcine kidney cells. Mycoplasma hyopneumoniae grown in Friis mycoplasma broth was radiolabeled with 35[S]-methionine, washed, concentrated, and inoculated on the monolayers. After 15 minutes of centrifugation to facilitate adherence, monolayers were washed 3 times, dissolved with 0.1N NaOH, and suspended in scintillation liquid, and the radioactivity was determined in a liquid scintillation counter. Adherence, measured as a percentage of counts added, varied according to the mycoplasma strain and the cell line used. Comparison of strains J, 144L, and 232 of M hyopneumoniae revealed 7.5 +/- 5.9, 31.9 +/- 13, and 9.6 +/- 5% adherence to porcine kidney cells, respectively. Slightly different, but proportionally the same relationships were obtained with swine or human fibroblasts. Adherence was decreased slightly by repeated washings of the mycoplasma-treated cell monolayers; however, a plateau was reached, indicating irreversibility of the adherence process. Pretreatment of cell monolayers with nonlabeled organisms substantially blocked adherence by labeled organisms. Dilution of labeled organisms resulted in an increased proportion adhering. Therefore, it appears that the adherence was a receptor-dependent event. Treatment of the mycoplasmas with trypsin prior to the inoculation of monolayers resulted in a marked reduction in adherence. Treatment of the mycoplasmas with hyperimmune swine serum against M hyopneumoniae or normal swine serum resulted in 80 to 90% reduction of adherence; however, no inhibition occurred when mycoplasmas were treated with purified IgG from the hyperimmune serum.