Radiological examination of the spinal column in farmed rainbow trout Oncorhynchus mykiss (Walbaum): experiments with Flavobacterium psychrophilum and oxytetracycline

Flavobacterium psychrophilum and oxytetracycline have both been associated with spinal deformities in salmonids. Experiments were carried out to investigate whether infection with F. psychrophilum or medication with oxytetracycline (OTC) at the fry stage would result in an increased occurrence of vertebral column deformities in rainbow trout, Oncorhynchus mykiss (Walbaum). Fish were on‐grown for 9 months and examined by radiology at the end of the experiments. There was a relationship between infection by F. psychrophilum and deformities of the spinal column, if fish with more than 10 affected vertebrae were classified as deformed. The deformities found among infected fish were often visible externally and were more severe than those seen among control fish (most deformities foun among controls were only seen on X‐ray photographs). Deformities were evenly spread along the vertebral column of infected fish. OTC treatments of up to 200 mg of OTC (kg fish)^?1 day^?1 for 10 days and repeated three times did not result in increased spinal deformities relative to untreated control groups; therefore, medication of rainbow trout with oxytetracycline did not cause deformities of the spinal column under our treatment conditions.     

Endogenous Amino Acid Flow in the Duodenum of Dairy Cows

In an inbred pig family founded by commercial breeds, nine microsatellite markers from porcine chromosome 4 were screened to find associations with weight gain and fat deposition traits. In this family showing a linear decrease in weight gain with inbreeding, an association (P <0.05) was found between average daily slaughter gain and markers S0214 and S0373 located at approximately 88 and 98 cM in the linkage map constructed in this study. No association (P >0.05) between backfat thickness and marker genotypes could be detected. Furthermore, the genotypes of the markers showed a surprisingly high degree of heterozygosity in all of the inbred generations, even though the theoretical inbreeding coefficients reaching 0.59.     

Carbon-13--rich diagenetic carbonates in miocene formations of california and Oregon

Carbon unusually rich in C(13)(deltaC(13) = +5.4 to +19.0 per mil relative to the Peedee belemnite carbonate standard of the University of Chicago) is characteristic of certain diagenetic limestones and dolomites in the Miocene Monterey Shale of California and the Nye Mudstone of Oregon. This heavy carbon may have originated through low-temperature equilibration between CO(3)- - and CO(2) in migrating carbonated waters or between CH(4) and CO(2) in natural gas. Light carbon (deltaC(13) = -5.6 to -18.2 per mil) derived through nonequilibrium oxidation of organic matter also occurs in the carbonate of Monterey Shale in some localities, but at most places it is much less common than heavy carbon.     

Serogroups and antimicrobial susceptibility among Escherichia coli isolated from farmed mink (Mustela vison Schreiber) in Denmark

Escherichia coli is commonly found in outbreaks of diarrhoea in mink during the production season although its role as a primary causal organism remains unclear. The present study was undertaken to determine the serogroups and antimicrobial susceptibility of E. coli isolates from healthy and diarrhoeic mink. Rectal swabs were taken from healthy and diseased animals, on six different farms, once at the onset of disease and again approximately 2 weeks later. The swabs were subjected to bacteriological investigation; a total of 210 E. coli were isolated, 98 from healthy animals and 112 from diseased. All isolates were serotyped and MICs were determined for nine antimicrobial compounds. Non-haemolytic isolates numbered 147, whereas 63 were haemolytic. Both haemolytic and non-haemolytic isolates were isolated from both healthy and diseased animals.A wide range of serogroups was detected, the most frequent being O2 (11.0%), O78 (11.0%), O153 (7.1%), O25 (5.7%), O6 (4.8%), and O15 (4.8%), but diarrhoea was not associated with specific serogroups. All isolates were sensitive to enrofloxacin, neomycin, gentamicin and colistin. In contrast, considerable variations in susceptibility were found among the six mink farms, for tetracycline (0-46.4%, average 21.9), ampicillin (2.9-50.0%, average 23.3), spectinomycin (8.0-35.7%, average 21.9), sulfamethoxazole (8.6-57.7%, average 30.0) and trimethoprim (0-35.7%, average 9.5). Resistance to tetracycline was statistically more prevalent among haemolytic than among non-haemolytic strains.In conclusion, serogrouping and haemolysin testing failed to identify any association with diarrhoeal disease and antimicrobial resistance was highly variable between different mink farms.     

Complications associated with tibial plateau leveling osteotomy: A retrospective of 1519 procedures

This retrospective study identified complications associated with tibial plateau leveling osteotomy (TPLO) and predisposing factors for these complications in a large population of dogs from a metropolitan area with cruciate ligament deficiency. There were 943 dogs that underwent unilateral TPLO and 288 with staged bilateral TPLO for a total of 1519 procedures. There were 47 cases with at least 1 major complication and 126 cases with at least 1 minor complication but no major complications. The total complication rate (major or minor) was 11.4% [95% confidence interval (CI) estimate: 9.8%, 13.2%]; the major complication rate was 3.1% (95% CI: 2.3%, 4.1%); and the minor complication rate was 8.3% (95% CI: 7.0%, 9.8%). Factors associated with development of complications included being a German shepherd dog [odds ratio (OR): 3.2], tibial plateau angle > 30° (OR: 1.6), and heavier weights (for every 4.5 kg increase in body weight the OR increased by 1.10). Tibial plateau leveling osteotomy is a common treatment for dogs with cruciate ligament deficiency and has a low complication rate.     

Factors regulating ovarian function in pigs

The hormonal interactions of the hypothalamic-pituitary-ovarian-uterine axis are accountable for a normal reproduction in female pigs. It is of importance to have knowledge of estrous symptoms and hormonal profiles around ovulation. The introduction of the transrectal ultrasonography in sows has given us the possibility to study ovarian activity in conscious animals and relate the timing of estrus to ovulation. Combining this technique with measuring of several hormones like luteinizing hormone (LH), follicle-stimulating hormone (FSH), inhibin, estradiol, progesterone, insulin-like growth hormone I (IGF-I), prostaglandin F2alpha (PGF2alpha) metabolite, oxytocin, facilitate our knowledge about the sequence of ovarian events. Evidence suggests that activation of the hypothalamic-pituitary-adrenal axis may hamper the normal gonadotropin secretion and in consequence, the ovarian function. The metabolic status during lactation, weaning of piglets and social stress might affect onset of ovarian activity and the related estrous behavior. The role of seminal plasma, artificial insemination and presence of the boar might also be included as factors regulating the temporal kinetics of ovulation, corpus luteum development, uterine function and steroid production in the ovary. Studies using a simulated stress by means of adrenocorticotrophic hormone (ACTH) administration or food deprivation are tools in understanding how the ovary is susceptible to impairment. The intention of this paper is to review current knowledge concerning the endocrine aspects of normal and stress-influenced ovarian function in pigs.     

Water recirculation and good management: potential methods to avoid disease outbreaks with Flavobacterium psychrophilum

Flavobacterium psychrophilum infections cause high mortality among rainbow trout, Oncorhynchus mykiss, fry in Danish fish farms and hatcheries. Hatcheries based entirely on bore‐hole water recirculation systems have been suggested as a possibility for eliminating F. psychrophilum or at least keeping the amount of this bacterium low. The occurrence of the bacterium in a bore‐hole water recirculation system was compared with a combined bore‐hole water and stream water flow‐through system in a hatchery where outbreaks of rainbow trout fry syndrome caused by F. psychrophilum often occurred. Broodfish, unfertilized and fertilized eggs, eyed eggs and fry, as well as water samples from the tanks/troughs with broodfish/fry, were examined. Suspect yellow bacterial colonies were either confirmed or rejected as F. psychrophilum by growth characteristics and by PCR. As both virulent and less virulent F. psychrophilum isolates are known, isolates were characterized. The isolates were ribotyped and grouped according to ribotyping patterns. Representatives of the groups were serotyped. Fry isolates were very homogeneous whereas isolates from broodfish were heterogeneous, whether the isolates originated from external surfaces of the fish (mucus from skin and gills, haemorrhages and ulcers) or internal organs. Flavobacterium psychrophilum was isolated from broodfish in both water systems; 56% of investigated broodfish from the borehole/flowthrough system and 36% from the recirculation facility harboured the bacterium. In the recirculation system, the bacterium was isolated from fish (ulcers, milt, liver, abdominal cavity) kept in the system for 11 months. Flavobacterium psychrophilum was found in milt and ovarian fluid as well as on the surface of fertilized eggs, but not inside the eggs. Fry also harboured F. psychrophilum, but in the water recirculation system the bacterium was first isolated from the fry after they had been graded. Flavobacterium psychrophilum was found regularly in other parts of the hatchery (outside the recirculation facility), including at the time of grading, suggesting that the occurrence of F. psychrophilum in the fry recirculation facility was due to contamination from the borehole/flowthrough hatchery. It is suggested that the combination of bore‐hole water recirculation systems and good management procedures (including egg disinfection) is a possible method for hatcheries to avoid disease outbreaks due to F. psychrophilum.     

Genetic population structure and variation at phenology-related loci in anadromous Arctic char (Salvelinus alpinus)

The Arctic will be especially affected by climate change, resulting in altered seasonal timing. Anadromous Arctic char (Salvelinus alpinus) is strongly influenced by sea surface temperature (SST) delimiting time periods available for foraging in the sea. Recent studies of salmonid species have shown variation at phenology-related loci associated with timing of migration and spawning. We contrasted genetic population structure at 53 SNPs versus four phenology-related loci among 15 anadromous Arctic char populations from Western Greenland and three outgroup populations. Among anadromous populations, the time period available for foraging at sea (>2°C) ranges from a few weeks to several months, motivating two research questions: (a) Is population structure compatible with possibilities for evolutionary rescue of anadromous populations during climate change? (b) Does selection associated with latitude or SST regimes act on phenology-related loci? In Western Greenland, strong isolation by distance at SNPs was observed and spatial autocorrelation analysis showed genetic patch size up to 450 km, documenting contingency and gene flow among populations. Outlier tests provided no evidence for selection at phenology-related loci. However, in Western Greenland, mean allele length at OtsClock1b was positively associated with the time of year when SST first exceeded 2°C and negatively associated with duration of the period where SST exceeded 2°C. This is consistent with local adaptation for making full use of the time period available for foraging in the sea. Current adaptation may become maladaptive under climate change, but long-distance connectivity of anadromous populations could redistribute adaptive variation across populations and lead to evolutionary rescue.     

Endoscopic sealing of a chronic bronchopleural fistula using acrylate co-monomer glue

A bronchopleural fistula (BPF) consists of a direct communication between the bronchial tree and the pleural space, which can develop secondary to (pleuro) pneumonia. Thoracotomy has been reported as a viable treatment option in cases of nonresponsive pleuropneumonia, pleural abscess formation and necrotising pneumonia. The presence of a BPF can delay and even prevent healing of the thoracotomy site, with clinical signs of coughing and putrid purulent nasal discharge often seen. In this case report, we describe the diagnosis and localisation of a bronchopleural fistula using retrograde instillation of methylene blue through the thoracotomy site, followed by the successful closure of the BPF using endoscopic application of acrylate co-monomer glue (Glubran 2^®).