Although hepatobiliary disease is common in cats, little is known about the bile composition in either these diseased states or in healthy cats. The objectives of this study were to evaluate several analytes from the bile of healthy cats and to investigate the usefulness of measuring these variables to predict bacterial cholangitis. Cats were prospectively enrolled and divided into 3 groups: 21 healthy cats (group 1) and 14 cats with suspected hepatobiliary disease: 9 without bacterial biliary infection (group 2) and 5 with bacterial biliary infection (group 3). Percutaneous ultrasound-guided cholecystocentesis was conducted on each cat. Bile cytology and culture were carried out and bile was analyzed for pH, lactate, and glucose levels using several point-of-care (POC) devices. Reference values for several bile analytes in healthy cats were calculated and are presented in this study. Neither the pH (P = 0.88) nor the lactate concentration (P = 0.85) was significantly different among the 3 groups. Sodium concentration was significantly higher in group 3 than in group 2 (P < 0.05). Bile pH, lactate, and glucose levels were unable to predict the presence of a bacterial infection in the bile.

Bronchoalveolar lavage was performed through an endotracheal tube in 34 specific-pathogen-free cats to determine expected values for bronchoalveolar lavage fluid cytologic analysis, using this method of collection. Saline solution for lavage was instilled in 3 separate aliquots at a volume of 5 ml/kg of body weight each. Analysis of sequential aliquots was performed to investigate the differences in cell counts among the 3 fractions. The effect of combining aliquots, including or omitting the first fraction, was evaluated to determine whether all aliquots could be combined for analysis without substantially affecting results. The total number of nucleated cells retrieved from each cat ranged from 0.9 to 31.1 X 10(6). Most of these cells were macrophages (78 +/- 15%, mean +/- SD) and eosinophils (16 +/- 14%). The first aliquot had the greatest number of epithelial cells, and the lowest total nucleated cell count and relative and absolute eosinophil counts. Differences among aliquots also were identified for relative and absolute macrophage counts, relative and absolute neutrophil counts, and absolute lymphocyte count. Statistically significant differences were found for many of the cell counts when values from the combination of the second and third aliquots were compared with values from the combination of all 3 aliquots. Magnitude of the differences was small, and these differences were not believed to be of practical consequence.

Physical, biochemical, and cytologic properties of synovial fluid from digital flexor tendon sheaths of clinically normal horses were investigated. Tendon sheath fluid was pale yellow, clear, and did not clot. Volume of fluid within a tendon sheath varied minimally, with a mean of 2.11 ml. Total erythrocyte counts were higher than values observed in normal equine joint fluid, whereas values for total leukocyte count (770 +/- 73 cells/mm3), viscosity (6.05 +/- 0.58 cs), and protein concentration (7.87 +/- 0.03 mg/ml) were similar to those in joint fluid. Large mononuclear cells were the predominant synovial fluid cell type. Mean hyaluronic acid concentration (0.74 +/- 0.02 mg/ml) and mucinous precipitate quality were lower than values in joint fluid.

Chemical and cytologic effects and bactericidal activity of gentamicin in septic synovial fluid were evaluated in an experimental model of infectious arthritis in horses. Septic arthritis was induced by inoculation of approximately 7.5 x 10(6) colony-forming units of Escherichia coli into 1 antebrachiocarpal joint in each of 16 clinically normal adult horses. Clinical signs of septic arthritis were evident 24 hours after inoculation. Horses were allotted to 3 groups: group-1 horses (n = 5) each were given 150 mg of gentamicin (50 mg/ml; 3 ml) intra-articularly (IA); group-2 horses (n = 5) each were given 2.2 mg of gentamicin/kg of body weight, IV, every 6 hours; and group-3 horses (n = 6) each were given buffered gentamicin, consisting of 3 mEq of sodium bicarbonate (1 mEq/ml; 3 ml) and 150 mg of gentamicin (50 mg/ml; 3 ml), IA. Synovial fluid specimens were obtained at posttreatment hour (PTH) 0, 0.25, 1, 4, 8, 12, and 24 via an indwelling intra-articular catheter. Synovial fluid pH was evaluated at PTH 0, 0.25, and 24. Microbiologic culture and cytologic examination were performed on synovial fluid specimens obtained at PTH 0 and 24, and gentamicin concentration was measured in all synovial fluid specimens. At PTH 0, E coli was isolated from synovial fluid specimens obtained from all horses. Synovial fluid pH was lower (range, 7.08 to 7.16) and WBC count was higher (range, 88,000 to 227,200 cells/microliter) and predominantly neutrophilic (95 to 99%) at PTH 0 than before inoculation. Synovial fluid pH was lowered further (mean, pH 6.63) after IA administration of gentamicin in group-1 horses; mean pH remained unchanged (7.07) after buffered-gentamicin administration in group-3 horses. At PTH 0.25, mean peak synovial fluid gentamicin concentration in horses of groups 1 and 3 (4,745 and 6,190 microgram/ml, respectively) was 1,000 times greater than that in group-2 horses (5.1 microgram/ml) at the same time. Synovial fluid gentamicin concentration in group-1 and group-3 horses was always greater than that in group-2 horses and remained greater than a minimal inhibitory concentration of gentamicin (2 microgram/ml) against many common equine bacterial pathogens for at least 24 hours after injection. Further, the calculated apparent half-life and clearance of gentamicin in synovial fluid calculated after IA administration were similar in horses of groups 1 and 3. By PTH 24, E coli could not be isolated from synovial fluid specimens obtained from group-1 horses. However, moderate to heavy growth of E coli was isolated from synovial fluid specimens obtained at PTH 24 from horses in groups 2 and 3 (80 and 66%, respectively). In selected cases, IA administration of unbuffered gentamicin may be a useful supplement to drainage, lavage, and systemic antibacterial and anti-inflammatory treatment in horses with naturally acquired infectious arthritis.

Quantitative evaluation of neutrophil chemotaxis was performed on cells obtained by hypotonic-lysis techniques from heparinized blood samples from clinically normal dogs. The techniques resulted in neutrophil recovery rates between 60 and 80%. Chemotaxis comparisons were based on cellular migration in microchambers equipped with polycarbonate membranes with 5-micrometer pores. Chemo-attractant comparisons were based on neutrophil migration to medium, normal canine plasma, zymosan-activated plasma, and xanthine oxidase. Cellular migration to zymosan-activated plasma in buffer (1:100 dilution) was significantly (P less than 0.001) enhanced over random baseline medium migration. Neutrophil migrations to normal canine plasma and xanthine oxidase were quantitatively less than to zymosan-activated plasma, but were equivalent to each other and significantly greater than for random migration. Migration to xanthine oxidase was maximal at concentrations near 1 U/ml within 30 minutes.

Objective: To develop a broad-range 28S ribosomal DNA quantitative PCR (qPCR) assay for detection of fungal DNA in equine endometrial samples. Sample: 12 fungal samples from a clinical diagnostic laboratory and 29 samples obtained from 17 mares. Procedures: The qPCR assay was optimized with commercially acquired fungal organisms and validated with samples obtained from the clinical diagnostic laboratory. Subsequently, 29 samples from 17 mares suspected of having fungal endometritis were evaluated via the qPCR assay and via traditional fungal culture and endometrial cytology. Amplicons from the qPCR assay were subjected to genetic sequencing to identify the organisms. Results: The qPCR assay theoretically had a detection threshold of 2 organisms of Candida albicans. Fungal DNA was amplified from all 12 fungal samples from the commercial diagnostic laboratory. Fungal identification by use of genetic sequencing was successful for 34 of 36 amplicons from the 12 samples assayed. A fungal agent was identified via qPCR assay and genetic sequencing in all 12 samples; in contrast, a fungal agent was identified in only 8 of 12 samples via standard fungal culture and biochemical analysis. The qPCR assay detected fungal DNA in samples from 12 of 17 mares suspected of having fungal endometritis. Conclusions and Clinical Relevance: A rapid, sensitive, and repeatable qPCR assay was developed for detection of fungal DNA from equine endometrial samples. The qPCR may prove to be clinically useful as an adjunct to microbial culture and cytologic examination to provide identification of fungal organisms in a timely manner.

Cytologic examination of bronchoalveolar lavage fluid (BALF), including phenotypic analysis of lymphocytes, was performed on 32 Standardbreds with poor race performance and endoscopic examination findings characteristic of inflammatory airway disease (IAD). Nucleated cell counts in BALF from IAD-affected horses were higher than those in control horses; the cytologic profile of BALF in affected horses included mixed inflammation, characterized by mild neutrophilia, lymphocytosis, and monocytosis. Eosinophil and mast cell counts were not higher in the IAD-affected group, compared with those in the control group; however, 4 IAD-affected horses had marked eosinophilia (24.7 +/- 4.8% SEM) in BALF. Phenotypic analysis of lymphocytes in BALF obtained from IAD-affected horses revealed a low proportion of CD4-positive cells and B cells, compared with those in the control group; these findings may have been representative of a greater proportion of non-B, non-T cells (null cells) in horses with IAD. The cytologic profile of BALF obtained from horses with IAD differed from that in horses affected with chronic obstructive pulmonary disease, suggesting that the pathogenesis of inflammation in horses with IAD may differ from that of chronic obstructive pulmonary disease.

Tracheobronchial aspirates obtained from 66 healthy Thoroughbred racehorses in training at the same track were examined. Twenty-seven percent of the horses had > 20% neutrophils in the aspirate. Eosinophils, mast cells, giant cells, and Curschmann's spirals of mucus were observed in 94, 83, 65, and 42% of the horses, respectively. Hemosiderophages were observed in 86% of the horses, half of which had previous confirmation of exercise-induced pulmonary hemorrhage. Although fungal elements were seen in 70% of the horses, bacteria were detected in only 3% of the horses. The authors conclude that inflammatory airway disease is widespread in the racing Thoroughbred population.

Thirty-eight tracheobronchial aspirates (TBA) were collected from twenty 1 to 6-month-old foals, which were free of clinical signs of respiratory tract or other infectious disease. We collected TBA from 9 of the foals 3 times when they were approximately 8, 16, and 24 weeks old. Aspirates were examined cytologically after staining with modified Wright-Giemsa, Gram, toluidine blue, and prussian blue stains. Aerobic bacterial culturing was performed on all aspirates. Of the 20 initial TBA, 4 (20%) were normal cytologically on the basis of previously defined criteria for TBA from clinically normal horses, 6 (30%) had a high percentage of eosinophils (> 5%), 8 (40%) were classified as indicative of subacute inflammation, and 2 (10%) were classified as indicative of acute inflammation. Nine (45%) were positive for mast cells and none were positive for hemosiderin-laden macrophages (hemosiderophages). Of the 9 foals from which samples were collected at 16 and 24 weeks of age, results were similar, except for an increase in the number of TBA classified as indicative of chronic inflammation (33% and 22% respectively) and the number positive for hemosiderophages (33% and 88%, respectively). One TBA was considered nondiagnostic because of pharyngeal contamination. Culturing of 12 of the 37 aspirates (32%) yielded a potential microbial pathogen. Only 2 were positive cultures from the same foal. The following organisms were isolated: beta-hemolytic Streptococci spp (4), Actinobacillus/Pasteurella spp (4), Rhodococcus equi (2), unidentified nonenteric Gram-negative rod (1), and Escherichia coli (1). Thirty-four of the 37 aspirates (92%) yielded light growth of various organisms considered to be nonpathogenic and normal inhabitants of the upper respiratory tract. It was concluded that the presence of inflammatory cells, eosinophils, and mast cells in the tracheobronchial aspirates from clinically normal foals is a common finding. These cytologic findings were consistent in the samples collected from foals at 8, 16, and 24 weeks of age. It was also concluded that bacteria with recognized pathogenicity can be isolated from TBA from clinically normal foals and were most frequently isolated from 1- to 2-month-old foals or those with cytologic evidence of inflammation, even in the absence of clinical signs of respiratory tract disease.

Cytologic and bacteriologic responses, and changes in cytokine activity were evaluated in secretions of Staphylococcus aureus-infected mammary glands after treatment of heifers with recombinant bovine interferon gamma (rbIFN gamma) or interleukin 2 (rbIL-2). Two groups of 4 heifers each, experimentally infected with 10(7) colony-forming units (CFU) of S aureus, were injected in 2 quarters via the teat canal, with 10(5) U of rbIFN gamma (trial 1) or 7.5 X 10(5) U of rbIL-2 (trial 2) 2 weeks after experimentally induced infection; control quarters received phosphate-buffered saline solution. Mammary secretion samples were taken on days 0, 1, 2, 3, 4, 7, and 14 after cytokine infusion. Secretions were diluted 1:10 and used to perform somatic cell counts (SCC), differential cell counts, and CFU enumerations, and to determine the number of leukocytes expressing major histocompatibility complex class-II (MHC II) antigens. In addition, mammary secretion samples taken on days 0, 1, and 2 were processed to obtain skimmed milk for evaluation of rbIFN gamma- and rbIL-2-like activities. Treatment with rbIFN gamma did not influence SCC, or differential or bacteria counts, or the number of leukocytes expressing MHC II antigens. However, rbIL-2 stimulated leukocytosis, which may have reduced bacteria counts early in the trial; treatment with this cytokine also increased the neutrophil, macrophage, lymphocyte, and eosinophil counts in secretions. Similarly, numbers of MHC II-positive leukocytes were greater in rbIL-2-treated quarters vs controls. Compared with day 0, IFN gamma-like activity was increased on only day 1 in both trials. Interleukin-2-like activity was not influenced in the rbIFN gamma trial, but was increased on days 1 and 2 in the rbIL-2 trials. Results indicated that neither cytokine may have had a major influence on the course of established S aureus infections. However, the increased SCC in rbIL-2-treated quarters may have accounted for the reduction in CFU throughout the trial after treatment with this cytokine. Greatest cytokine-like activity was observed on day 1; however, the consequences of cytokine activity, such as the sustained eosinophilia after rbIL-2 treatment, were detected over the 14-day trial period, indicating possible prolonged action.