In a search of viral agents in pulmonary macrophages of horses with chronic pulmonary disease, equine herpesvirus 2 was found to be unique. In 8 of 9 horses with chronic pulmonary disease, antigens of equine herpesvirus 2 were detected by indirect immunofluorescence staining of scattered foamy macrophages immediately after harvesting by bronchoalveolar lavage and fractionation on metrizamide gradients. In a healthy horse, antigens were not found. After 1 week of cultivation of bronchoalveolar lavage cells from a second group of 9 horses with chronic pulmonary disease, viral antigens were detected in 90% of the adherent pulmonary macrophages. In 2 of 3 healthy horses, viral antigens also were found in 90% of the adherent pulmonary macrophages. Antigens of equine herpesvirus 1, equine herpesvirus 4, parainfluenza virus 3, or adenovirus were not detected. Antigens of the 5 investigated viruses also were not detected in lung tissue slices from a third group of 14 horses, 4 healthy; 7 with varying degrees of bronchiolitis, 2 of which also had chronic intestitial pneumonia; 2 with eosinophilic bronchitis; and 1 with pulmonary hemorrhage. The exclusive presence of equine herpesvirus 2 in pulmonary macrophages was confirmed qualitatively by isolation of infective virus by cocultivation. In a fourth group of 12 horses with chronic pulmonary disease, infective virus could be isolated from pulmonary macrophages of 3 horses and from mixed-blood leukocytes of 5 horses. Virus isolations from 2 healthy horses were not successful from pulmonary macrophages, whereas 1 isolation was obtained from mixed-blood leukocytes. Other viruses were not detected by cocultivation.

By use of wire ropes as the transosseous component, an external skeletal fixator for the repair of long bone fractures in horses and cattle has been designed and tested in axial compression. Theoretical methods were used in the design process to size fixator components; however, our results suggest that conventional methods of analyzing the displacement of the transosseous component may not apply to wire ropes. Large pretensions in the wire ropes are necessary to obtain functional stiffnesses for fracture fixation. Therefore, a method was sought for terminating the ropes so that an appropriate pretension could be introduced into the rope through its interface with the fixator rings. Ropes were terminated by use of 5 methods and were tested in axial tension to failure. These methods included 3 copper sleeve arrangements, welded ends, and drum sockets. The drum sockets (57.6% of rope breaking strength) far exceeded the strengths provided by the copper sleeves (8.5 to 26.6%) and the welded ends (44.3%). Using the drum sockets, 5 rope configurations were assembled to the fixator, using wood blocks to simulate bones with a gap defect. The fixator was loaded in axial compression for each of the rope configurations, and stiffnesses were determined from measured axial displacement and applied load. The 4-ring fixator configuration, with 2 ropes at 60 degrees angular separation/ring, was the stiffest. In a worst case (gap) model, a mean axial compression load of 1,730 N was observed at 2 mm of displacement for a 4-ring fixator configuration. Our results suggest that, in less conservative scenarios where compression of the fracture surfaces can share limb loads, wire ropes may function well as the transosseous components of an external fixator.

Marked differences in bone marrow cellularity were observed between cattle affected with leukocyte adhesion deficiency (LAD) and control cattle. The number of nucleated cells in bone marrow was 2.9 to 8.8 times higher in cattle affected with LAD, compared with controls. The myeloid-to-erythroid ratio of bone marrow from 3 cattle affected with LAD ranged from 2.4 to 12. Deficient CD18 expression on neutrophils isolated from bone marrow of cattle with LAD was clearly detected by flow cytometric analysis. Neutrophils from bone marrow of cattle affected with LAD appeared round and not flat, after adherence to plastic wells under agarose, whereas neutrophils from bone marrow of clinically normal cattle were firmly spread on the surface of plastic wells. In the chemotaxis under-agarose assay, many pseudopodia were detected on bone marrow neutrophils from clinically normal cattle, but were not detected on bone marrow neutrophils from cattle with LAD. Activities of chemotactic movements and phagocytosis of neutrophils isolated from bone marrow of cattle affected with LAD were documented to be severely impaired.

We compared the anesthetic combination of detomidine, ketamine, and halothane in control horses not undergoing apparently painful procedures with that in horses during arthroscopic surgery. The effectiveness of this regimen in suppressing neurologic response to surgery was, thus, evaluated. In this study, significant differences were not observed in electroencephalographic total amplitude, spectral edge, or beta-to-delta frequency ratio between surgically treated and nonsurgically treated (control) horses. On the basis of its attenuation of encephalographic responses, we conclude that detomidine (20 microgram/kg of body weight, IV) and ketamine (2.2 mg/kg, IV) induction of anesthesia followed by maintenance with halothane is an effective regimen for control of pain in horses during arthroscopic surgery. The insignificant frequency changes observed without any other signs of inadequate anesthesia or pain may indicate a surgical stress response. We hypothesize that brain activity monitoring may give an earlier index to initiation of surgically induced stress than do hormonal responses, because endocrine alterations are not as rapidly perceived as is the electroencephalogram. Analysis of spectral edge frequency changes could be used to evaluate anesthetic regimens to find those that cause the least stress to the CNS during surgery in horses. Differences in species responses to an anesthetic agent or the regimen's effectiveness in prevention of pain during surgery may be identified by adoption of the study model. Evaluation of cardiopulmonary variables during anesthesia, with and without surgery, did not reveal any alterations that would be relevant to CNS responses. Blood pressure, heart rate, PAO2, PACO2 and pH were stabilized by use of intermittent positive-pressure ventilation in all horses, and dobutamine was administered as needed, to avoid bias of electroencephalogram data.

Reduced prevalence of diarrhea and mortality has been reported after dietary supplementation with zinc compounds in swine with naturally acquired colibacillosis and those challenge-exposed with Serpulina hyodysenteriae; however, the usefulness of this approach for control of enteric diseases of swine remains to be determined. To examine the effect of dietary zinc-containing compounds on the colonization and development of cecal lesions associated with S hyodysenteriae infection, a defined diet alone or with added ZnO, ZnSO4, or Zn-methionine complex to a final concentration of approximately 6,000 mg of Zn2+/kg of complete feed was fed ad libitum to 156 female mice (strain C3H/HeN) for 10 days prior to oral inoculation either with S hyodysenteriae or sterile trypticase soy broth. Rations were continued for 42 days, while at weekly intervals, 3 mice/group were necropsied for determination of body weight, cecal weight, liver zinc concentration, presence of S hyodysenteriae in the cecum, and gross and histologic assessments of cecal lesions. From postinoculation day 0 to 42, the liver zinc concentration of mice fed the zinc-supplemented diets was approximately twice that of mice fed the basal diet, irrespective of the source of zinc. From postinoculation day 7 through 42, the overall recovery rate of S hyodysenteriae in infected mice fed the basal diet was 77.8%. In contrast, recovery rates of S hyodysenteriae from S hyodysenteriae-inoculated mice fed the zinc-supplemented diets were 0% for Zn-methionine and ZnO and 16.7% for ZnSO4. Mice fed the basal diet had significantly (P < 0.05) higher weight gain than mice fed the zinc-supplemented diets. However, the severity of cecal lesions, as determined by histologic examination and quantitative determination of longitudinal crypt length of the cecum was significantly (P < 0.05) less in mice fed the zinc-supplemented diets than in mice fed the basal diet. Data from this study indicate that dietary supplementation with 6,000 mg of zinc/kg of feed significantly reduced the recovery rate of S hyodysenteriae and provided partial protection against development of cecal lesions in mice inoculated with S hyodysenteriae. However, at this concentration, zinc had a deleterious effect on growth of the mice.

The concentration of carbonic anhydrase III isoenzyme (cA-III) in serum samples from 216 clinically normal Thoroughbreds was determined by use of an enzyme immunoassay. The concentration range of cA-III was from 16.0 to 254.5 ng/ml (mean, 56.5 +/- 11.9 ng/ml). Significant differences were not detected according to age or sex. To confirm whether serum cA-III concentration was high in horses with muscle disease, serum samples of 11 horses with exertional rhabdomyolysis were analyzed by enzyme immunoassay. Their serum cA-III concentration was about 56 times (3,136 +/- 2,610 ng/ml) that of healthy Thoroughbreds. Concentration of cA-III was higher in horses with rhabdomyolysis that had been transiently recumbent than in horses with mild disease that were reluctant to move. Blood samples obtained serially from 6 horses with exertional rhabdomyolysis were studied. Serum activities of aldolase, creatine kinase, aspartate transaminase, and lactate dehydrogenase were high. Increases and decreases in concentration of cA-III were more rapid than that for aldolase, creatine kinase, aspartate transaminase, and lactate dehydrogenase activities; thus, cA-III may be clinically applicable as a diagnostic marker for muscle disease in horses.

The stability of ionized calcium (CaI) concentration and pH in sera (n = 14) stored at 23 or 4 C for 6, 9, 12, 24, 48, or 72 hours, or -10 C for 1, 3, 7, 14, or 30 days was evaluated. Also studied were the effects of oxygen exposure, cold handling, and feeding on CaI and pH values. Results indicated that serum CaI concentration was stable throughout 72 hours of storage at 23 or 4 C, and for 7 days at -10 C. Serum CaI concentration significantly (P < 0.05) decreased by 14 days of storage at -10 C. Serum pH was stable for 6 hours at 23 or 4 C, and for 24 hours at -10 C, but significantly (P < 0.05) increased by 9 hours of storage at 23 or 4 C and by 3 days at -10 C. Exposure of the surface of the serum to air immediately before measurement had no effect on CaI or pH values, but mixing serum with air resulted in significantly (P < 0.05) decreased CaI concentration and increased pH. Handling of blood on ice resulted in significantly (P < 0.05) higher serum pH, compared with blood handled at 23 C, but serum CaI concentration was unaffected. Serum obtained at 2 hours after feeding did not have any significant changes in CaI, total calcium, or pH values. It appears that if canine serum is obtained, handled, and stored anaerobically, CaI concentration can be accurately measured after 72 hours at 23 or 4 C, or after 7 days at -10 C.

Aflatoxin (AF)-contaminated and fumonisin B1 (FB1)-contaminated (culture material from Fusarium moniliforme) diets were fed singly and in combination to growing cross-bred barrows. Six barrows (3 replicates of 2 each; mean body weight, 17.5 kg) per group were fed: 0 mg of AF and 0 mg of FB1/kg of feed (control); 2.5 mg of AF/kg of feed; 100 mg of FB1/kg of feed; or 2.5 mg of AF plus 100 mg of FB1/kg of feed for 35 days. The effects on production performance, serum biochemical, hematologic, immunologic, and pathologic measurements were evaluated. Body weight, gain, and feed consumption were significantly (P < 0.05) decreased by AF and AF plus FB1 diets. The FB1 diet decreased feed consumption, and although body weight was numerically decreased, it was not statistically significant. Aflatoxin increased serum gamma-glutamyltransferase (GGT) activity and total iron concentration and decreased urea nitrogen concentration and unsaturated iron-binding capacity. The FB1-alone diet increased serum GGT activity, whereas the AF plus FB1 diet increased serum aspartate transaminase, cholinesterase, alkaline phosphatase, and GGT activities, increased RBC count, triglycerides, and total iron concentrations, and decreased unsaturated iron-binding capacity and urea nitrogen concentration. For the most part, the effects of the AF plus FB1 diet on body weight and hematologic measurements could be considered additive. However, the effect of the AF plus FB1 diet on cholinesterase and alkaline phosphatase activities was greater than additive and was a synergistic response. One pig in the FB1-diet group and 2 pigs in the combination-diet group died. Postmortem lesions in pigs of the FB1-diet group consisted of ascites and increased liver weight. Observations at necropsy for pigs of the AF plus FB1-diet group consisted of hydrothorax, ascites, pulmonary edema, gastric erosions and ulceration, and increased liver and spleen weights. The AF diet increased relative liver weight and resulted in liver that was pale, rubbery, and resistant to cutting. Histologic lesions consisted of hepatic necrosis or degeneration, or both, with variable degrees of bile duct proliferation in barrows of the AF-diet groups. Renal tubular nephrosis was observed in barrows of the FB1 diet group, but this was not consistent in the AF plus FB1-diet group. Cell-mediated immunity, as measured by mitogen-induced lymphoblastogenic stimulation index, was decreased in barrows of the AF and FB1-diet groups, and values in barrows given the combination diet were significantly decreased from those in barrows given the single toxin diets. It was concluded that AF and FB1 (from culture material), singly or in combination, can adversely affect clinical performance, serum biochemical, hematologic, and immunologic values and induce lesions in growing barrows. For most of the variables we evaluated under our study conditions and dosages of toxins, measurements were affected more by the combination diet than by either single toxin diet, and the toxic responses could be described as additive or more than additive, particularly for induction of liver disease.

Objective-To develop a system for analysis of immune response variables in the lymph draining the lung and to establish baseline data for clinically normal calves. Design-Surgery was performed on 6 calves to insert a cannula into the efferent lymphatic duct of the caudal mediastinal lymph node to create a long-term thoracic lymph fistula draining to the exterior. Lymph was collected daily, and on the fifth postoperative day, calves were exposed to an aerosol of cell culture medium (mock infection). For the next 10 days, lymph was collected for analysis and, on the tenth day, necropsy was performed. Animals-Six 6- to 8-week-old Holstein bull calves. Procedure-Daily lymph samples were evaluated for: flow rate; total and differential cell counts; and IgG, IgM, IgA, IgE, and protein concentrations. On days -4, -1, 1, 4, 7, and 10, cells were stained and quantitated by fluorescence-activated cell sorter analysis for T, B, CD4+, and CD8+ cells. Blood lymphocytes were evaluated on days -1 and 10 for comparison. Results-Flow was established for up to 25 days, with a mean rate between 11 and 22 ml/h. Protein concentrations in lymph and plasma did not indicate a protein drain. Although mean lymphocyte counts reflected a slight gradual decrease in lymph lymphocytes, this effect was not apparent in every calf, nor was the effect seen in blood lymphocytes. There were no significant changes in IgG, IgM, IgA, or IgE concentration, with the exception of IgA concentration in 1 calf that developed an abscess at the cannulation site. The T-cell subset absolute numbers of CD4+ and CD8+ cells decreased slightly over time, but the CD4+-to-CD8+ cell ratio remained almost constant at near 2. Conclusion-Creation of a thoracic lymphatic fistula appears to be a useful technique for studying effects of lung infection on immunologic variables, with potential application to bacterial and viral respiratory tract diseases.

To measure the concentration of serum amyloid A (SAA) protein in horses a sensitive and highly reproducible sandwich (ELISA) was established, using affinity purified SAA antibody. Results of the ELISA were found to have a high correlation (r = 0.95) with those of the single radial immunodiffusion test. Equine SAA concentration was measured by use of this ELISA. In clinically normal horses, the concentration of SAA was high immediately after birth to 2 weeks of age. After that, SAA concentration had periodic fluctuations in the range of approximately 10 to 30 microgram/ml. Mean (+/- SD) concentrations of SAA in foals (less than or equal to 12 months old) and adult horses (greater than or equal to 18 months old) were 21.23 +/- 12.20 and 14.93 +/- 9.07 microgram/ml, respectively. In mares during the perinatal period, SAA concentration remained stable within the reference range before parturition. It increased quickly after delivery, and reached a peak value of 101.29 +/- 98.82 microgram/ml on postpartum day 3, then began to decrease, at postpartum week 2, to the reference range by the end of postpartum month 1. In horses with experimentally induced inflammation, SAA concentration increased quickly and reached approximately four- to 40-fold increase over the pretreatment value on day 1 and remained high on days 2 to h after treatment. It then returned to the baseline value by 2 to 4 weeks in association with disappearance of local signs of inflammation. The SAA concentration was high in most horses with clinical signs of inflammation. It was concluded from these data that this ELISA is sensitive and reliable for measuring SAA in horses.