DUPLEX-ULTRASONOGRAPHIC EVALUATION OF THE COMMON CAROTID ARTERY IN THE RESTING, SEDATED AND ANESTHETIZED HORSE

The aim of this study was to determine the blood flow in the carotid artery during halothane anaesthesia by means of duplex-sonography. Seventeen warm blood horses were evaluated in dorsal and lateral recumbency and the results were compared with the values of the same horses resting and under sedation. The cross sectional area of the vessels, the time-averaged maximal blood velocity, time-averaged maximal blood flow and the resistance index were determined and the flow profile was evaluated. During halothane anesthesia the total blood flow shows a significant increase which is not dependent on the positioning of the horse. Mean blood velocity is decreased by sedation and significantly increased during anesthesia. Reduced peripheral resistance is expressed by a decline of the resistance index. After sedation and during recumbency there is an increase in diameter of the carotid artery.     

Semi‐quantitative methods yield greater inter‐ and intraobserver agreement than subjective methods for interpreting 99mtechnetium‐hydroxymethylene‐diphosphonate uptake in equine thoracic processi spinosi

Scintigraphy is a standard diagnostic method for evaluating horses with back pain due to suspected thoracic processus spinosus pathology. Lesion detection is based on subjective or semi‐quantitative assessments of increased uptake. This retrospective, analytical study is aimed to compare semi‐quantitative and subjective methods in the evaluation of scintigraphic images of the processi spinosi in the equine thoracic spine. Scintigraphic images of 20 Warmblood horses, presented for assessment of orthopedic conditions between 2014 and 2016, were included in the study. Randomized, blinded image evaluation was performed by 11 veterinarians using subjective and semi‐quantitative methods. Subjective grading was performed for the analysis of red‐green‐blue and grayscale scintigraphic images, which were presented in full‐size or as masked images. For the semi‐quantitative assessment, observers placed regions of interest over each processus spinosus. The uptake ratio of each processus spinosus in comparison to a reference region of interest was determined. Subsequently, a modified semi‐quantitative calculation was developed whereby only the highest counts‐per‐pixel for a specified number of pixels was processed. Inter‐ and intraobserver agreement was calculated using intraclass correlation coefficients. Inter‐ and intraobserver intraclass correlation coefficients were 41.65% and 71.39%, respectively, for the subjective image assessment. Additionally, a correlation between intraobserver agreement, experience, and grayscale images was identified. The inter‐ and intraobserver agreement was significantly increased when using semi‐quantitative analysis (97.35% and 98.36%, respectively) or the modified semi‐quantitative calculation (98.61% and 98.82%, respectively). The proposed modified semi‐quantitative technique showed a higher inter‐ and intraobserver agreement when compared to other methods, which makes it a useful tool for the analysis of scintigraphic images. The association of the findings from this study with clinical and radiological examinations requires further investigation.     

UNILATERAL COMPLETE OBSTRUCTION OF THE PRIMARY BRONCHUS IN TWO JUVENILE MACAWS (ARA SPP.)

Two juvenile macaws presented independently with clinical signs associated with respiratory signs that included coughing, wheezing, and increased respiratory effort and rate. Whole body radiographis were obtained from one patient, and were considered normal. Computed tomography identified unilateral complete primary bronchial obstruction in both cases. Tracheoscopy was performed in both cases and identified a partial obstruction of the syrinx in one case. Biopsy samples collected during tracheoscopy were submitted for microbial culture. Aspergillus spp. was isolated and treatment was unsuccessful for this macaw. The second case was euthanized upon diagnosis. In both cases, a complete necropsy confirmed the primary bronchial obstruction and fungal organisms were identified, consistent with Aspergillus spp. As demonstrated by these two cases, radiography and tracheoscopy do not allow for the diagnosis of primary bronchial obstruction in birds. Therefore, a computed tomography scan is recommended to accurately diagnose this condition in avian patients.     

Phenological phases of common beech (Fagus sylvatica L.) and their dependence on region and altitude in Southern Germany

Long-term observational data of the phenological network of the German Weather Service (DWD) were used to derive the altitudinal dependence of leaf unfolding (LU), leaf discolouration (LD) and the length of the vegetation period (LD-LU) of common beech (Fagus sylvatica L.) in different regions of Southern Germany. Depending on altitude, the vegetation period starts in Bavaria between the 2nd and 24th May with a delay of around 2 days per 100 m altitude increase (averaged over the last 30 years). In Southern Bavaria, LU starts a few days earlier as well as increases slightly faster into higher altitudes than in the northern regions. This can be explained by a more favourable supply of warmth and radiation in the south. The end of the vegetation period, defined here as the beginning of LD, showed no altitudinal dependence, which reflects an interaction of endogenous and exogenous factors as triggers for LD. In the Bavarian Forest region, altitudinal dependences are strongly influenced by sites which are affected by cold-air tailback (‘Kaltluftstau’) was obtained. Hence, phenological gradients should only be derived and applied above a phenological inversion zone. The calculated vertical gradients for LU can be used together with available observational data to estimate the beginning of the forest vegetation period of beech for different altitudes of Bavaria.     

Impact of late frost events on radial growth of common beech (Fagus sylvatica L.) in Southern Germany

Phenological, temperature, and tree-ring data were used in order to identify and quantify the impact of late frosts on common beech (Fagus sylvatica L.) at different altitudes in Southern Germany during the last century. For this intention, dendroecological investigations were made upon trees at the Meteorological Observatory Hohenpeißenberg as well as from seven stands in the Bavarian Forest and 17 stands at the northern fringe of the Alps. From these locations, a considerable number of severe growth minima in the tree-ring series could be related to late frost in the days of or immediately after leaf unfolding. The frequency of frost-related growth minima increases with altitude. In individual years, radial growth can be reduced by more than 90% (stand mean) in relation to the average growth of the ten previous years. Hence, late frosts are considered as important ecological events that strongly affect beech vitality and competitiveness especially at high altitudes. Evidence of significant impacts on radial growth by late frosts distinct before leaf unfolding or with temperatures above ?3°C was not found. Also, increasing frequency and intensity of late frosts during recent decades were not ascertained. Hence, the recently observed decreased vitality of common beech accompanied by growth depressions especially at high altitude sites in Central Europe cannot be explained as a consequence of late frost damage.