Timo Soveri

Etiology of respiratory disease in non-vaccinated, non-medicated calves in rearing herds.

Abstract The aim of this study was to examine the occurrence of bacterial, mycoplasmal and viral pathogens in the lower respiratory tract of calves in all-in all-out calf-rearing units. According to clinical status, non-medicated calves with and without respiratory disease signs were selected of the 40 herds investigated to analyse the micro-organisms present in healthy and diseased calves. Tracheobronchial lavage (TBL) and paired serum samples were analysed for bacteria, mycoplasmas, respiratory syncytial virus (RSV), parainfluenza virus 3 (PIV3), bovine corona virus (BCV) and bovine adenovirus (BAV). Pasteurella multocida was the most common bacterial pathogen. It was isolated from 34% of the TBL samples in 28 herds and was associated with clinical respiratory disease (p <0.05) when other pathogenic bacteria or mycoplasma were present in the sample. Mannheimia spp. and Histophilus somni were rarely found. Mycoplasma bovis was not detected at all. Ureaplasma diversum was associated with clinical respiratory disease (p <0.05). TBL samples from healthy or suspect calves were more often negative in bacterial culture than samples from diseased calves (p <0.05). No viral infections were detected in six herds, while 16–21 herds had RSV, BCV, BAV or PIV3. In the herds that had calves seroconverted to BCV, respiratory shedding of BCV was more frequently observed than faecal shedding. This study showed that the microbial combinations behind BRD were diverse between herds. M. bovis, an emerging pathogen in many countries, was not detected.

Association of bovine respiratory disease with clinical status and acute phase proteins in calves.

Abstract Eighty-four calves with respiratory disease from 18 herds in different parts of Finland were chosen for a study evaluating the capacity of different respiratory pathogens to cause changes in different acute phase protein concentrations, white blood cell (WBC) count and clinical signs. The selected acute phase proteins were fibrinogen, haptoglobin, serum amyloid-A, lipopolysaccharide binding protein and α1-acid glycoprotein. From each calf, a paired blood sample was obtained for serological studies of bovine parainfluenza virus-3, bovine respiratory syncytial virus, bovine coronavirus, bovine adenovirus-3 and bovine adenovirus-7. Tracheobronchial lavage was performed to detect bacteria and mycoplasma. Isolation of Pasteurella multocida was associated with increased concentrations of all tested acute phase proteins. For other pathogens, no significant relationships were observed. No association was present between viral or bacterial findings and WBC count.

Viral and Bacterial Pathogens in Bovine Respiratory Disease in Finland

AbstractPathogens causing bovine respiratory tract disease in Finland were investigated. Eighteen cattle herds with bovine respiratory disease were included. Five diseased calves from each farm were chosen for closer examination and tracheobronchial lavage. Blood samples were taken from the calves at the time of the investigation and from 86 calves 3–4 weeks later. In addition, 6–10 blood samples from animals of different ages were collected from each herd, resulting in 169 samples. Serum samples were tested for antibodies to bovine parainfluenza virus-3 (PIV-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), bovine adenovirus-3 (BAV-3) and bovine adenovirus-7 (BAV-7). About one third of the samples were also tested for antibodies to bovine virus diarrhoea virus (BVDV) with negative results. Bacteria were cultured from lavage fluid and in vitro susceptibility to selected antimicrobials was tested. According to serological findings, PIV-3, BAV-7, BAV-3, BCV and BRSV are common pathogens in Finnish cattle with respiratory problems. A titre rise especially for BAV-7 and BAV-3, the dual growth of Mycoplasma dispar and Pasteurella multocida, were typical findings in diseased calves. Pasteurella sp. strains showed no resistance to tested antimicrobials. Mycoplasma bovis and Mannheimia haemolytica were not found.SammanfattningFörekomst av luftvägspatogener vid enzootisk pneumoni i finska nötbesättningar Studien genomfördes under åren 1998–1999 för att få grundkunskap om förekomsten av infektionsämnenassocierade med kalvarnas luftvägsinfektioner i Finland. Alla 18 besättningarna hade problem med luftvägssjukdomar. I varje besättning utvaldes 5 sjuka kalvar för noggrann undersökning och tracheobronkiell sköljning. För serologiska undersökningar av virusantikroppar togs blodprov från 86 kalvar med 3–4 veckors mellanrum. Från samma besättningar togs dessutom 6–10 serumprov från nöt i olika åldersgrupper, sammanlagt 169 prov. Serumproverna analyserades för antikroppar mot parainfluensavirus typ3 (PIV-3), bovint respiratoriskt syncytialt virus (BRSV), bovint coronavirus (BCV), bovint adenovirustyp 3 (BAV-3) och bovint adenovirus typ 7 (BAV-7). En tredjedel av proverna analyserades dessutompå antikroppar mot bovint virusdiarrevirus (BVDV) med negativt resultat. De tracheobronkiella skjölproverna undersöktes på mykoplasmer och andra bakterier. Enligt serologiska resultat tycks PIV-3, BAV-7, BAV-3, BCV och BRSV förekomma allmänt hos besättningar med luftvägssjukdomar i Finland. Serokonversion konstaterades oftast mot BAV-7 och BAV-3. I bakteriologiska undersökningar av sköljprovenisolerades bara få patogener. De mest allmänna bakterieisolaten var Mycoplasma dispar och Pasteurellamultocida tillsammans. Alla Pasteurella sp. isolat var känsliga för testade antibiotika. Mannheimia haemolytica och M. bovis kunde inte påvisas i något prov.

Acute phase protein changes in calves during an outbreak of respiratory disease caused by bovine respiratory syncytial virus.

Abstract Bovine acute phase proteins (APPs), lipopolysaccharide binding protein (LBP), serum amyloid A (SAA), haptoglobin (Hp) and alpha1-acid glycoprotein (AGP) were evaluated as inflammatory markers during an outbreak of bovine respiratory disease (BRD) caused by bovine respiratory syncytial virus (BRSV). Calves (n =10) presented mild to moderate signs of respiratory disease. Secondary bacterial infections, Pasteurella multocida and Mycoplasma dispar as major species, were detected in tracheobronchial lavage samples. Concentrations of SAA and LBP increased at week 1 had the highest values at week 3 and decreased at week 4 of outbreak. Some calves had high Hp concentrations at week 3, but AGP concentrations did not rise during respiratory disease. Higher SAA, LBP and Hp concentrations at a later stage of BRD (week 3) were associated with the low BRSV-specific IgG1 production, suggesting that these calves had enhanced inflammatory response to the secondary bacterial infection. In conclusion, APPs (especially SAA and LBP) are sensitive markers of respiratory infection, and they may be useful to explore host response to the respiratory infections in clinical research.

Disease patterns in field and bank vole populations during a cyclic decline in central Finland

Declining field vole (Microtus agrestis) and bank vole (Clethrionomys glareolus) populations were sampled (117 field voles and 34 bank voles) in south-central Finland during the winter of 1988-89. The last surviving field voles were caught in April and bank voles in February. A subsample (16) of the April field voles were taken live to the laboratory for immunosuppression. The histopathology of the main internal organs and the presence of aerobic bacteria and certain parasites were studied. In the lungs, an increase in lymphoid tissue, probably caused by infections, was the most common finding (52% of all individuals). The prevalences in the voles, in the whole material, of Chrysosporium sp. and Pneumocystis carinii in lungs were 13 and 10% in field voles, and 9 and 0% in bank voles, respectively. Cysts of Taenia mustelae (9 and 27%) were the most common pathological changes in the liver. Enteritis was also rather common (14 and 34%). In field voles the prevalences of Frenkelia sp. in the brain and Sarcocystis sp. in leg muscles were low (both 6%). Bordetella bronchiseptica was commonly (31%) isolated from field vole lungs and Listeria monocytogenes from the intestines (34%). Salmonella spp. could not be found. The dynamics and abundance of inflammations in the lungs and intestines, as well as B. bronchiseptica isolations from the lungs, indicate that obvious epidemics took place in declining vole populations. Of the Luhanka subsample of 16 field voles brought to the laboratory in April, one died of listeriosis, two of Bordetella, and five died for unknown reasons. Even if small mustelids are the driving force in microtine cycles, it is possible that diseases also contribute to the decline.

Serum Cortisol Levels in Goats Exhibit Seasonal But Not Daily Rhythmicity

The aim of the study was to find out whether there is a daily rhythm in goat serum cortisol concentrations, whether the concentration profiles differ between normal light:dark and constant dark conditions, and whether any seasonal variations might be detected in daily cortisol secretion patterns. Seven Finnish landrace goats were kept at indoor temperature (18–23°C) under artficial lighting that approximately simulated the annual changes of daylength at 60°N. Blood samples were collected for cortisol measurements by radioimmunoassay at 2h intervals during six times of the year: winter (light:dark 6:18h), early spring (10:14h), late spring (14:10h), summer (18:6h), early fall (14:10h), and late fall (10:14h). Cortisol profiles were determined for two consecutive days, first in light:dark (LD) conditions and then in continuous darkness (DD). There was no significant daily rhythm in serum cortisol levels in any time of the year, nor did the profiles in LD and DD conditions show any differences. A significant seasonal variation was, however, detected among the overall cortisol levels. In winter, the concentrations were higher than in any other season, and from early spring to summer they were at their lowest. Under equal photoperiods, the cortisol levels were higher in fall than spring. The difference between winter and summer was confirmed in the following year in LD conditions. There was no correlation between the serum cortisol and progesterone levels. The results suggest that the possible circadian variation of cortisol secretion in goats is completely masked by external factors, and the lighting conditions do not have immediate effects on the daily secretion patterns. The seasonal variation in the overall cortisol levels is most probably related to the changes in photoperiod, because other conditions were relatively constant during the experiment.

Serum acute phase proteins as a marker of inflammation in dairy cattle with hoof diseases

HOOF health is an important animal welfare and economic issue for dairy producers. Many studies have shown how lameness, usually due to hoof lesions ([Murray and others 1996][1]), can affect ovarian activity, udder health, milk yield and the risk of culling ([Green and others 2002][2], [Hultgren and

Seasonal variation in endogenous serum melatonin profiles in goats: a difference between spring and fall?

The pineal hormone melatonin serves as a signal of day length in the regulation of annual rhythms of physiological functions and behavior. The duration of high melatonin levels in body fluids is proportional to the duration of the dark period of the day. Due to the direct suppression of melatonin by light, the overt melatonin rhythm may differ from the endogenous rhythm driven by the hypothalamic circadian clock. The aim of this study was to find out possible differences between the overt and endogenous melatonin rhythms in goats during the course of a year. Seven Finnish landrace goats (nonlactating females) were kept under artificial lighting that approximately simulated the annual changes of day length at 60°N. Blood samples for melatonin measurements by radioimmunoassay were collected at 2-h intervals during six seasons: winter (light:dark 6:18 h), early spring (10:14), late spring (14:10), summer (18:6), early fall (14:10), and late fall (10:14). Melatonin profiles were determined for 2 consecutive days, first in light-dark (LD) conditions and then in continuous darkness (DD). In LD conditions, the profiles matched the dark period with one exception: in winter, the mean peak duration was significantly shorter than the scotoperiod. In DD conditions, two types of endogenous melatonin patterns were found: a “winter pattern” (peak duration 13–15 h) in winter, early spring, early fall, and late fall, and a “summer pattern” (duration about 11 h) in late spring and summer. Thus, in equal habitual LD conditions in late spring and early fall (LD 14:10), the endogenous melatonin rhythms were not quite similar: the pattern in late spring resembled that in summer, and the pattern in early fall that in winter. These results suggest that, in addition to the light-adjusted overt melatonin rhythm, the endogenous rhythm of melatonin secretion varies during the course of a year.

Endothelial cell damage in piglet coronary artery after intravenous administration of E. coli endotoxin: A scanning and transmission electron-microscopic study☆

E. Coli endotoxin was administered to 6 piglets from a litter of 10. Three days after the endotoxin stimulus 3 piglets showed definitive morphological evidence of endothelial damage to their left coronary artery. The proximal parts of the coronary artery were severely damaged. In scanning electron microscopy, the changes varied from disappearance of the microvilli to complete exfoliation of the endothelial cells. In cases of severe endothelial cell damage transmission electron microscopy revealed severe changes or even signs of cell death in the inner medial smooth muscle cells. Only of the piglets died prematurely. We are sufficiently encouraged to continue testing the theory that repeated endothelial cell damage initiates stenosing lesions in the coronary arteries.

Prevalence of Cryptosporidium sp. in peak density Microtus agrestis, Microtus oeconomus and Clethrionomys glareolus populations.

The prevalence of Cryptosporidia was determined in high density populations of Microtus agrestis, Microtus oeconomus, and Clethrionomys glareolus in Finland. One of 131 M. agrestis and one of 41 C. glareolus each were found to be infected with Cryptosporidium sp.; none were found in 43 Microtus oeconomus. These apparently healthy voles had neither signs of clinical disease nor histopathological changes in intestines.