Neutrophil migration induced by equine respiratory secretions, bronchoalveolar lavage fluids and culture supernatants of pulmonary lavage cells

Supernatants of equine respiratory secretions enhanced the migration of equine neutrophils into the lower compartments of Boyden chambers. Checkerboard analysis revealed that the neutrophil migration promoting activity (NMPA) of secretion specimens was in great part caused by chemokinesis, irrespective of the neutrophil score of the specimen. The NMPA of respiratory secretions was correlated neither with the neutrophil score of the secretion specimen nor with the severity of the chronic pulmonary disease. Respiratory secretions collected while horses were kept under low dust or under dusty housing conditions induced migration of neutrophils in the same order of magnitude. The number of migrated neutrophils and the procoagulant activity (PCA) within respiratory secretion specimens was positively correlated; however, the meaning of this finding is not yet clear. None of the nine cell-free supernatants of bronchoalveolar lavage fluid, which were assayed undiluted, induced significant neutrophil migration, although some samples contained up to 4.0 x 10(5) neutrophils/ml. In vitro culture of lung lavage cells, which mainly comprised macrophages and lymphocytes, without stimulation or with the addition of low doses of phytohemagglutinin (PHA) resulted in the secretion of NMPA which was in great part chemotactic. However, culture supernatants of lung cell preparations which were stimulated by lipopolysaccharide (LPS) or by PHA-prestimulated lymphocytes reduced the migration of neutrophils compared with the supernatants of control cells. NMPA within culture supernatants had a highly significant negative correlation with the PCA of macrophages within the lung cell preparations. Our results imply that a complicated and sophisticated regulation underlies neutrophil accumulation within the airways of horses affected with chronic pulmonary disease. Future experiments are required to assess the biological significance of the factors modulating neutrophil migration which are present in the respiratory secretions and in the culture supernatants of equine lung lavage cells.     

Bronchoalveolar lavage of cranial and caudal lung regions in selected normal calves: cellular, microbiological, immunoglobulin, serological and histological variables.

Of a group of 30 clinically normal male Holstein calves two to eight weeks of age, six two week old and six four week old calves met various radiographical and clinicopathological criteria for normality. Bronchoalveolar lavage was performed by fiberoptic bronchoscopy on cranial and caudal lung regions in all 30 calves and samples analyzed for free cells, microorganisms, and immunoglobulins. Lateral chest radiographs and lung biopsies were also conducted on each calf. Calves were euthanized and necropsied ten days after bronchoalveolar lavage was conducted. Reported in this paper are results from the 12 normal calves. Microorganisms were present in small numbers in the lower respiratory tract of some normal calves. There were no differences in the above parameters between cranial and caudal lobes. There were statistically significant changes in bronchoalveolar lavage cell proportions with age although there were no detectable differences in clinical signs. Four week old calves had a lower percentage of macrophages and a higher percentage of epithelial cells than two week old animals (p less than 0.05). There was also a trend toward an increased percentage of neutrophils in older calves but this was not significant (p greater than 0.05). Total bronchoalveolar lavage protein also appeared to increase with age (p less than 0.05). In both groups a higher proportion of IgG2 in bronchoalveolar lavage compared to serum was found, suggesting the presence of a local selective transfer mechanism into respiratory secretions.     

Cytologic, microbiologic, and biochemical analysis of bronchoalveolar lavage fluid obtained from 24 healthy cats

Twenty-four healthy cats underwent bronchoscopy and bronchoalveolar lavage to determine the normal cytologic environment of the lower respiratory tract of cats. Initial screening to ensure the health of the study population included complete histories, physical examinations, thoracic radiography, CBC, serologic tests for feline leukemia virus, feline immunodeficiency virus, and occult heartworm, and sugar and Baermann fecal flotation. In 18 cats, protected catheter brush samples of airway secretions from the lavaged lung segment were taken for culture of aerobic and anaerobic bacteria and mycoplasma. Bronchial lavage fluid (5 sequential 10-ml aliquots of normal saline solution) was pooled and filtered with cotton gauze. The unspun sample was used for determination of a total nucleated cell count. Lavage fluid was cytocentrifuged and 500 cells/slide were scored for determination of the cellular differential. Activity of lactate dehydrogenase and concentrations of total protein and IgG within the supernatant were measured, and assays were performed to detect the presence of IgA and IgM. Complete histologic evaluation of the lavaged lung of each of 6 random-source cats was performed after differential cell counting revealed 18% eosinophils within bronchoalveolar lavage fluid recovered from this group. Alveolar macrophages were the predominant cells encountered; however, a quarter of all cells recovered were eosinophils. A significant relationship was not found between the abundance of eosinophils in the lavage fluid, and either isolation of aerobic bacteria, high total nucleated cell counts, total protein concentrations, or activity of lactate dehydrogenase. Histologic evaluation of the lungs of 5 of 6 random-source cats revealed normal lungs in 2 cats, and minimal abnormal change in 3 others. Evaluation of the lungs from 1 random source cat revealed acute, mild eosinophilic bronchiolitis. We conclude that large numbers of eosinophils may be retrieved from the bronchoalveolar lavage fluid of healthy cats.     

Bronchoalveolar lavage fluid findings in the atelectatic regions of anesthetized horses

To evaluate the effects of compression atelectasis on the composition of pulmonary secretions in anesthetized horses, cytological and biochemical examinations were performed on bronchoalveolar lavage (BAL) fluids obtained from both dependent and independent lung regions. Six horses were anesthetized with isoflurane and oxygen for 120 min, and were positioned in right lateral recumbency. Percentage of neutrophils and total protein concentration in BAL fluids significantly increased at the end of anesthesia, and total phosphorous concentration significantly decreased at 72 hr after anesthesia in dependent lung. Such changes were not observed within 168 hr after anesthesia. These findings suggest that the effects of compression atelectasis on the composition of pulmonary secretions may be eliminated within 168 hr after anesthesia.     

Effect of sodium cromoglycate on light racehorses with elevated metachromatic cell numbers on bronchoalveolar lavage and reduced exercise tolerance

Some young horses with clinical signs of small airway disease demonstrate increased metachromatic cell numbers on bronchoalveolar lavage. The purpose of this study was to determine the effect of sodium cromoglycate treatment on clinical signs, bronchoalveolar lavage cytology and bronchoalveolar lavage histamine parameters in these horses. Twelve racehorses (age: 3.4 ± 1.6 years) with a history of respiratory embarrassment at exercise, clinical signs of obstructive airway disease and bronchoalveolar lavage metachromatic cell differential greater than 2% were selected. Horses were randomly assigned to receive either 200 mg sodium cromoglycate or saline placebo nebulized twice daily for 7 days. A clinical respiratory score was assigned and bronchoalveolar lavage was performed on each animal on days 0 and 7. Measurements were made of the following bronchoalveolar lavage fluid parameters: total nucleated cell concentration, differential cell percentage and concentration, supernatant and lysate histamine concentration, lysate: supernatant histamine ratio and metachromatic cell histamine content. Between the two evaluation periods, sodium cromoglycate treated horses demonstrated an improvement in respiratory score (P = 0.01) and a stabilizing of metachromatic cell histamine content (P = 0.04) when compared with placebo treated horses. We conclude that sodium cromoglycate is effective for the treatment of small airway disease in this population of young racehorses although the pharmacodynamics of this drug in the horse require further investigation.     

Bronchoalveolar lavage cytology in cynomolgus monkeys and identification of cytologic alterations following sequential saline lavage

Total and differential cell counts were determined on cytolytic specimens obtained by fiberoptic bronchoscopy and bronchoalveolar lavage (BAL) of five normal cynomolgus monkeys. Total nucleated cell counts ranged from 100 to 430 cells/microliters. Macrophages were approximately 91% of total nucleated cells, while lymphocytes were 3%, neutrophils 4%, and eosinophils 2% of the initial BAL from each monkey. Less than 1% of the cells were mast cells and ciliated or nonciliated epithelial cells. The effects of repeated saline BAL on pulmonary cell populations were evaluated. Saline lavage of individual lung lobes resulted in a marked rise in circulating blood neutrophils at 4 hr after BAL; there was a similar rise in neutrophils in lavage fluids 24 hr after the initial lavage. Differential and total cell counts of both blood and lavage fluid returned to normal if subsequent lavages were spaced at 48-hr intervals. Lymphocytes were not present in saline-lavaged lung lobes, and protein levels of lavage fluids did not rise significantly. BAL produced a transient, reversible, intra-alveolar influx of neutrophils which was preceded by mobilization of bone marrow-stored neutrophils. Neutrophilia in the lavage fluid and blood was not detectable if lavage and blood sampling procedures were done at 48-hr intervals (which did not alter Ia antigen expression among BAL cells). These observations indicate that BAL is a valid method for sampling and assessing pulmonary cellular and fluid constituents if the procedures are done at intervals of at least 48 hr.     

Changes in leukocyte populations in pulmonary lavage fluids of calves after inhalation of Pasteurella haemolytica

The distribution of leukocytes in bovine bronchoalveolar lavage fluids was determined in 15 calves at various times after aerosol exposure to Pasteurella haemolytica. For comparison, 10 calves were exposed to aerosols of phosphate-buffered saline solution; 15 calves, to Staphylococcus epidermidis; and 10 calves, to Salmonella typhimurium endotoxin. At 10 minutes after inhalation exposure for each group, the predominant cell type was the macrophage. Macrophages remained the predominant cell type throughout each lavage interval for calves exposed to phosphate-buffered saline solution and Staph epidermidis. For calves exposed to P haemolytica, there was a decrease in the percentage of macrophages detectable by 30 minutes after exposure, with a corresponding increase in the percentage of neutrophils. Sixty minutes after the inhalation exposure to P haemolytica, the percentages of macrophages and neutrophils in the lavage fluid were equal. By 240 minutes after exposure to P haemolytica, greater than 90% of the cells in the lavage fluids was neutrophils. The increase in the percentage of neutrophils in lavage fluids from calves exposed to S typhimurium endotoxin was similar to that seen for the calves exposed to P haemolytica.     

Effects of inhalation of dust and endotoxin on respiratory tracts of pigs.

OBJECTIVE: To assess the effects of inhalation of feed flour dust and dustborne endotoxin on respiratory tracts of pigs. ANIMALS: 29 healthy Belgian Landrace pigs. PROCEDURE: Pigs housed in an environmental chamber were exposed for 6 days to feed flour dust (1 to 15 mg/m3) and dustborne endotoxins (50 to 2,500 ng/m3). Effects were evaluated by measuring albumin concentration, lactate dehydrogenase (LDH) activity, cell composition of nasal lavage (NL) and bronchoalveolar lavage (BAL) fluids and blood, and percentages of CD4+ and CD8+ T lymphocytes in blood and lavage fluids. Dustborne endotoxin was obtained by mixing endotoxins from Escherichia coli (serotype O127:B8) with feed flour before spraying the flour in the environmental chamber. RESULTS: Exposure did not affect cell composition of NL fluid or blood. Total cell counts of BAL fluids were increased in all groups exposed to dust. Macrophage counts were increased in pigs exposed to inhalable dust concentrations as low as 4.4 mg/m3, and lymphocyte counts were increased in groups exposed to high dust concentrations. Percentages of CD4+ and CD8+ T lymphocytes in blood and lavage fluids were unchanged. In all dust-exposed groups, albumin content of BAL fluid was increased, whereas LDH activity was unaffected. Macrophage and lymphocyte infiltration and edema in the bronchi were identified by light microscopy. Effects attributable to E. coli endotoxin exposure were not identified. CONCLUSIONS: Inhalation of feed flour dust did not affect nasal mucosa but did induce bronchial airway inflammation. Dustborne endotoxins did not have effects attributable to endotoxin alone.     

Using urea dilution to standardise components of pleural and bronchoalveolar lavage fluids in the dog

AIM: To develop a technique to estimate the volume of epithelial lining fluid (ELF) obtained during bronchoalveolar lavage (BAL) and pleural lavage (PL) in the dog, using the urea dilution method. METHODS: BAL and PL fluids were obtained by saline lavage of pulmonary and pleural cavities of nine clinically healthy mixed-breed dogs immediately after euthanasia. Cell counts in the BAL and PL fluids were measured using standard techniques. The concentration of ELF in each lavage fluid was calculated from the relative concentration of urea in plasma and in each type of lavage fluid. Cell counts in ELF were then calculated. RESULTS: There were substantially higher cell counts in ELF compared to BAL or PF fluid. However, nucleated cell counts in ELF could not be predicted from cell counts in BAL or PL fluid. CONCLUSIONS AND CLINICAL RELEVANCE: These results suggest that accurate assessment of cellular or non-cellular components in lavage fluids should include a calculation of the proportion of ELF recovered, using a method such as urea dilution.     

Isotype-specific antibody responses to bovine coronavirus structural proteins in serum, feces, and mucosal secretions from experimentally challenge-exposed colostrum-deprived calves.

Five newborn isolation-reared colostrum-deprived calves were inoculated orally and intranasally when they were 20 to 30 hours old and challenge exposed when they were 21 days old with a suspension of virulent bovine coronavirus (BCV). Blood, feces, nasal swabs, tears, saliva, and bronchoalveolar lavage (BAL) fluids were collected from each calf prior to inoculation and then weekly for 5 post-inoculation weeks. An ELISA was used to quantitate the immunoglobulin isotype titers of BCV antibodies in all samples. An immunoblot assay was used to determine the antibody isotype responses to BCV structural proteins in all the samples, except saliva. At postinoculation days 2 to 3, all calves had severe watery diarrhea, shed BCV in their feces, and had evidence of BCV replication in their upper respiratory tract. After challenge exposure, no calves became ill and no evidence of BCV replication in the respiratory or intestinal tracts was detected. At postinoculation week 1, IgM responses to the N protein were seen in mucosal secretions (except nasal fluid) and feces. At postinoculation weeks 2 and 3, IgA was predominant in mucosal secretions and feces directed toward all the BCV proteins (except the E2 protein in BAL fluid). After challenge exposure, an increase (or failure to decrease) in most IgA and some IgG1 titers to BCV proteins was seen. The increases in IgA titers were to all viral proteins in all mucosal secretions and feces, except to the N and E1 viral proteins in feces. The IgG1 titer increases were to the E2 proteins in tears and BAL fluid and to the E3 protein in BAL fluid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Post-exercise endoscopic and cytologic diagnosis of equine asthma syndrome in asymptomatic Brazilian pacers

The objectives were: 1. to investigate the occurrence of equine asthma syndrome (EAS) in a group of Campolina and Mangalarga Marchador horses through post-exercise respiratory endoscopy and cytology; 2. compare the efficiency of different diagnostic criteria; and 3. compare the incidence of EAS by breed, age group and sex. A standardised exercise test was conducted in the field, followed by respiratory endoscopy and bronchoalveolar lavage and fluid collection 30 min post-exercise. Clinical evaluation pre- and post-exercise, respiratory endoscopy post-exercise and bronchoalveolar lavage, also post-exercise, were conducted in 30 horses (15 Campolina and 15 Mangalarga Marchador) aged 3–18 years, without a history of respiratory illness and without clinical evidence of active respiratory disease. All horses were in active training and were considered fit to participate in equestrian competition characteristic of these breeds. Post-collection, the horses were subdivided into healthy or EAS-positive, depending on several diagnostic criteria. Statistical comparisons between breeds, age brackets (up to 7 years of age and above 7 years of age) and sex were conducted using appropriate statistical tests. According to bronchoalveolar lavage fluid (BALF) cytology, 56.7% of the horses showed at least one inclusion criteria that contributed to classification as EAS-positive. Of those, only one was classified as moderate EAS, while the others were classified as mild. Total cell count in the BALF above 530 cells/µL was the single most common diagnostic criteria (100%), followed by increased tracheal mucus (53%) at endoscopy, eosinophilia (47%) and neutrophilia (35%) in BALF. Significant differences were found between macrophage and lymphocyte numbers according to breed, but no other differences between breeds, age brackets, sex or status (healthy vs. EAS-positive). A high occurrence of EAS was found in competition-ready Mangalarga and Campolina pacer horses in this study.     

Using urea dilution to standardise components of pleural and bronchoalveolar lavage fluids in the dog

AIM: To develop a technique to estimate the volume of epithelial lining fluid (ELF) obtained during bronchoalveolar lavage (BAL) and pleural lavage (PL) in the dog, using the urea dilution method.

METHODS: BAL and PL fluids were obtained by saline lavage of pulmonary and pleural cavities of nine clinically healthy mixed-breed dogs immediately after euthanasia. Cell counts in the BAL and PL fluids were measured using standard techniques. The concentration of ELF in each lavage fluid was calculated from the relative concentration of urea in plasma and in each type of lavage fluid. Cell counts in ELF were then calculated.

RESULTS: There were substantially higher cell counts in ELF compared to BAL or PF fluid. However, nucleated cell counts in ELF could not be predicted from cell counts in BAL or PL fluid.

CONCLUSIONS AND CLINICAL RELEVANCE: These results suggest that accurate assessment of cellular or non-cellular components in lavage fluids should include a calculation of the proportion of ELF recovered, using a method such as urea dilution.     

Interaction of bovine respiratory syncytial virus with bovine alveolar macrophages in vivo: effects of virus infection upon selected cell functions.

The effect of bovine respiratory syncytial virus (BRSV) upon alveolar macrophage (AM) function was investigated using an in vivo calf inoculation model. Alveolar macrophages were collected sequentially from live calves at multiple time points during the 14 day period following viral inoculation. Alveolar macrophages from bronchoalveolar lavage fluids were purified by density gradient centrifugation (> 95% AM) prior to in vitro evaluation of cell functions. There were significant but variable and inconsistent differences in the functions of AM from the BRSV inoculated calves compared to the control calves. Fc-receptor mediated phagocytosis was either increased or unchanged by BRSV inoculation. Nonopsonized phagocytosis was decreased during the early postinoculation period and later increased. There was a variable effect on AM phagosome lysosome fusion with increased fusion activity on postinoculation days 2 through 5, 7 and 12 but reduced activity on days 6 and 10. The AM respiratory burst, as measured by nitroblue tetrazolium dye reduction, was essentially unaffected with a reduction in activity on day 10 only. In this model, BRSV inoculation of calves primarily resulted in an alteration of the membrane associated phagocytic functions of the alveolar macrophages (p < 0.05).     

The effect of isoprinosine and levamisole on factors relevant to protection of calves against respiratory disease

Experiments to characterize the effects of two immunomodulators, namely, isoprinosine and levamisole, on factors relevant to the resistance of calves to respiratory infection were undertaken. Daily oral doses of isoprinosine decreased the influx of neutrophils into the respiratory tract, increased membrane immunoglobulin and complement receptor expression on cells from bronchoalveolar lavage samples and decreased the severity of respiratory disease. Additional intravenous doses produced similar effects on neutrophil migration to the respiratory tract and on membrane receptor expression, but the changes were no greater than those seen with oral isoprinosine alone. No significant changes in the anti-bacterial activity of cells in bronchoalveolar lavage samples followed isoprinosine treatment. In vitro incubation of pulmonary alveolar macrophages harvested from normal calves with isoprinosine increased their expression of immunoglobulin and complement receptors. Levamisole did not affect neutrophil migration to the lower respiratory tract or membrane receptor expression by pulmonary alveolar macrophages after in vivo or in vitro treatment. The immunomodulatory effects of isoprinosine beneficially increase the resistance of calves to respiratory disease, and are potentially useful in the control of infectious diseases of farm animals.     

Effect of sex and age on the activities of lactate dehydrogenase and alkaline phosphatase in the lungs of rats.

Since toxicity studies among different laboratories generally involve rats of different sex and age, this study was conducted to investigate the effect of sex, age and animal to animal variation in the activities of lactate dehydrogenase and alkaline phosphatase from bronchoalveolar lavage fluid, bronchoalveolar cell lysate and lung homogenate. Correlation between numbers of bronchoalveolar cells recovered from lungs and enzyme activity in bronchoalveolar cell lysate or lung homogenate supernatant were also investigated. Male rats showed significantly (p less than 0.05) higher activities of alkaline phosphatase in the bronchoalveolar lavage fluid and lung homogenate. Animal to animal variation for lactate dehydrogenase and alkaline phosphatase was higher in lungs than in serum. The number of bronchoalveolar cells recovered from lungs revealed a significant (p less than 0.01) positive correlation with the activities of both enzymes in the supernatant of cell lysates but not in the bronchoalveolar fluid. These results indicated that in an inhalation study interindividual variation in the levels of pulmonary enzymes should be considered in order to minimize the numerous possible sources of experimental error.     

Comparison of bronchoalveolar lavage and respiratory secretion cytology in horses with histologically diagnosed pulmonary disease

Equine bronchoalveolar lavage (BAL) fluid collected from 70 horses and respiratory secretions (RS) obtained from 61 of these horses were evaluated cytologically and grouped according to the histological diagnosis of the lungs from which they were obtained. The histological categories included: normal lung (8 horses); pulmonary eosinophilic infiltration (9 horses); interstitial pneumonia (5 horses); pulmonary hemorrhage (5 horses); and mild (12 horses), moderate (7 horses) and severe (24 horses) chronic small airway disease. In horses with pulmonary disease, all BAL samples and all but one RS sample differed cytologically to those obtained from normal horses; however, the type and severity of the pulmonary disease could not always be determined using either BAL or RS cytology. There was a positive association between the percentage of neutrophils in BAL and the neutrophil scores in RS specimens; there was no positive association between other cell types.     

Effects of aerosolized albuterol on physiologic responses to exercise in standardbreds.

OBJECTIVE: To examine the effects of an aerosolized beta2-adrenoreceptor agonist, albuterol, on performance during a standardized incremental exercise test in clinically normal horses. ANIMALS: 8 Standardbred pacing mares. PROCEDURE: Clinically normal horses, as judged by use of physical examination, hematologic findings, serum biochemical analysis, and airway endoscopy, were randomly assigned to 2 groups and were given 900 microg of albuterol via a metered-dose inhaler 30 minutes before beginning a standardized incremental exercise test in a crossover design with a 7-day minimum washout. Further examination included measurement of baseline lung mechanics, response to histamine bronchoprovocation, and bronchoalveolar lavage. RESULTS: No significant differences (albuterol vs placebo) were seen for any incremental exercise test variables (ie, maximum oxygen consumption, maximum carbon dioxide consumption, respiratory quotient, treadmill speed at heart rate of 200 beats/min, or number of steps completed during an incremental exercise protocol). Mast cell percentage was significantly (r = -0.84) associated with the concentration of aerosolized histamine that evoked a 100% increase in total respiratory system resistance. No other direct correlations between bronchoalveolar lavage fluid cell types and any indices of exercise capacity or airway reactivity were found. CONCLUSIONS AND CLINICAL RELEVANCE: Although no horse had exercise intolerance, 4 horses had airway hyperreactivity with bronchoalveolar lavage fluid mastocytosis; these horses may have been subclinically affected with inflammatory airway disease. In our study, albuterol did not enhance performance in 8 clinically normal racing-fit Standardbreds.     

Comparison of bronchoalveolar lavage cytospins and smears in dogs and cats

Differences in the cytological interpretation of bronchoalveolar lavage fluid (BALF) after cytospin preparation (CP) or manual smearing of pelleted cells preparation (MSP) were investigated in client-owned dogs and cats with inflammatory or infectious lower respiratory disease. Bronchoalveolar lavage fluid from healthy cats was also examined. With MSP, cell lysis was more frequently observed, and cellular distribution was more heterogeneous throughout the slide. When samples from healthy and diseased animals were considered together, a significantly greater percentage of neutrophils was seen on CP than on MSP slides (P<0.002). Cytospin preparations were considered of better quality in all individual comparisons. Cytospin preparation is advised in the evaluation of BALF with low total cell count. When only MSPs are evaluated, clinicians should be aware that differential neutrophil counts may underestimate the counts found on CP slides.     

Isolation of mycoplasma species from the lower respiratory tract of healthy cattle and cattle with respiratory disease in Belgium

Between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six Mycoplasma species. Attempts were made to detect Mycoplasma canis, Mycoplasma dispar and Ureaplasma diversum in calves with recurrent disease, and all three of these species were identified in calves with recurrent disease and in healthy lungs. In healthy calves, 84 per cent of bronchoalveolar lavage fluids were mycoplasma free; when cultures were positive, Mycoplasma bovirhinis was the only species isolated. Mycoplasmas were isolated from 78 per cent of animals suffering recurrent respiratory disease and from 65 per cent of acute respiratory cases. Mycoplasma bovis was isolated from bronchoalveolar lavages from 35 per cent of calves suffering recurrent respiratory disease, and from 50 per cent of acute cases, and from 20 per cent of pneumonic cases examined postmortem. M bovis was associated with other Mycoplasma species in 44 per cent of cases. M dispar was also isolated from 45.5 per cent of calves suffering recurrent respiratory disease, often in association with M bovis. M canis was identified for the first time in diseased Belgian cattle. Other mycoplasmas, including Mycoplasma arginini, Mycoplasma alkalescens and U diversum, were isolated less frequently. Associations between mycoplasmas and other pathogens were often observed. Among lungs infected with Pasteurella and/or Mannheimia species, more than 50 per cent were mixed infections with M bovis.     

A retrospective analysis of feline bronchoalveolar lavage cytology and microbiology (1995-2000)

A retrospective study of 88 bronchoalveolar lavage specimens from 80 cats presenting to the University of Sydney Veterinary Centre between 1995 and 2000 was performed. Bronchoalveolar lavage cytology and microbiology in conjunction with other diagnostic aids and patient records were used to classify cases as lower respiratory tract infections (LTRIs), LRTI revisits, feline bronchial disease, cardiac disease, neoplastic disease and multisystemic disease. Cases for which a definitive diagnosis could not be made were classified as inconclusive. Infectious agents identified were Mycoplasma spp., Pasteurella spp., Bordetella bronchiseptica, Salmonella typhimurium, Pseudomonas sp., Cryptococcus neoformans, Aelurostrongylus abstrusus and Eucoleus aerophilus. The study highlights the importance of bronchoalveolar lavage cytology and microbiology in the evaluation of feline lower respiratory tract disease.