Tissue factor activated thromboelastography correlates to clinical signs of bleeding in dogs

The ability of a laboratory assay to correlate to clinical phenotype is crucial for the accurate diagnosis and monitoring of haemostasis and is therefore challenging with currently used routine haemostasis assays. Thromboelastography (TEG) is increasingly used to evaluate haemostasis in humans and may well be of value in the workup of dogs suspected of having a haemostatic disorder. This study was undertaken to evaluate prospectively how tissue factor (TF) activated TEG correlated to clinical signs of bleeding in dogs, compared to a routine coagulation profile. A prospective case-control study was performed over a 2 year period from 2004-2006. Eligible dogs were those where the primary clinician requested a coagulation profile to evaluate haemostasis. The dogs were simultaneously evaluated with a TF-activated TEG assay. Twenty-seven dogs, characterised as hypo-coagulable based on the TEG parameter G (<3.2 Kdyn/cm(2)), were included in the study as cases. Size matched control groups of TEG normo- (G=3.2K-7.2 Kdyn/cm(2)) and hyper-coagulable (G>7.2 Kdyn/cm(2)) dogs were selected retrospectively from the eligible dogs. For all dogs, clinical signs of bleeding were noted at time of analysis. There were statistically significant differences between all TEG values of hypo- and normo- and hyper-coagulable dogs. Thromboelastography correctly identified dogs with clinical signs of bleeding with a positive predictive value (PPV) of 89% and a negative predictive value (NPV) of 98% based on G alone. In comparison, the coagulation profile had a PPV between 50-81% and a NPV between 92-93% for detection of bleeding, depending on the observer. In conclusion, a TF-activated TEG G value<3.2K dyn/cm(2) correctly identified dogs with clinical signs of bleeding with very high PPV and NPV, irrespective of observer. The findings strongly suggest that TF- activated TEG may be of value in the workup of dogs suspected of having a haemostatic disorder.     

A comparison of the efficacy and cardiorespiratory effects of four medetomidine-based anaesthetic protocols in the red fox (Vulpes vulpes)

ObjectiveTo evaluate the anaesthetic and cardiorespiratory effects of four anaesthetic protocols in red foxes (Vulpes vulpes).Study designProspective, blinded and randomized complete block design.AnimalsTen adult captive red foxes.MethodsFoxes were anaesthetized by intramuscular (IM) injection using four protocols in random order: medetomidine 40 μg kg^?1, midazolam 0.3 mg kg^?1 and butorphanol 0.1 mg kg^?1 (MMiB), medetomidine 40 μg kg^?1 and ketamine 4 mg kg^?1 (MK40/4), medetomidine 60 μg kg^?1 and ketamine 4 mg kg^?1 (MK60/4), medetomidine 40 μg kg^?1 and tiletamine/zolazepam 2 mg kg^?1 (MTZ). Time to lateral recumbency, induction time and time to recovery following IM administration of atipamezole 0.2 mg kg^?1 were recorded. Heart rate (HR), respiratory rate (_fR) and rhythm, blood pressure, rectal temperature, end-tidal CO₂ tension (Pe′Co₂), functional oxygen saturation and presence/absence of interdigital, palpebral and ear reflexes were recorded every 10 minutes, and following administration of atipamezole. Data were analysed using two-way repeated-measures anova with Bonferroni post tests; p < 0.05 was considered significant.ResultsAll protocols produced profound sedation with good muscle relaxation. Only the MMiB protocol diverged significantly from the others. Induction of anaesthesia and recovery time following atipamezole were significantly longer, and f_R and initial HR significantly lower with MMiB than with the other protocols. With all protocols, mean arterial blood pressure (MAP) was initially relatively high (140–156 mmHg), and decreased significantly over time. With all protocols, the administration of atipamezole resulted in a rapid, significant decrease in MAP and an increase in HR.Conclusions and clinical relevanceAll four protocols provided anaesthetic conditions suitable for minor procedures and allowed endotracheal intubation. The cyclohexanone protocols provided quicker and more reliable inductions and recoveries than the MMiB protocol.     

The enhancement of cod stocks

Atlantic cod have been a primary target for marine stock enhancement since the 1880s. In the early part of this period, hatched larvae were released in Norway, the USA and Canada. The last larval releases were conducted in Norway in 1971, and a century of cod larvae releases were halted without any clear evidence of benefit. Since the early 1980s, the focus has been on production of larger, more viable juvenile cod. Emphasis has been given to the design of tag–release programmes involving large-scale releases and ecosystem analysis in selected ecosystems. Most of this research has been carried out in Norway, where more than one million tagged juvenile cod have been released. Smaller stocking experiments have also been performed in Denmark, Sweden, the Faroe Islands and the USA.
This paper reviews the major findings from these programmes. We include summaries and evaluations of rearing techniques for juvenile cod, methods of tagging and recapture, experimental fishing, migration, mortality and growth rates in the different habitats, genetic analysis, and ecosystem studies that have tried to describe the variation in the cod carrying capacity of selected release areas.
Despite relatively large variation in environmental conditions, in cod production and in fishing mortality along the Norwegian coast, results indicate that, under the conditions experienced during the 1980s and 1990s, releases of juvenile cod did not significantly increase cod production and catches. The biological limitations and future prospects of Atlantic cod stock enhancement are addressed.     

Voluntary responses and limits of tolerance to pressure reduction and swimbladder expansion in farmed Atlantic cod

Atlantic cod and other teleosts with closed swimbladders have slow gas resorption rates and are therefore vulnerable to sudden pressure reductions that lead to swimbladder expansion and possible loss of behavioural control. This problem is of particular relevance to fish farmers, who require safe protocols for lifting of cages containing cod that account for swimbladder expansion. To recommend a limit for pressure reduction, we experimentally determined the maximum pressure reduction, relative to neutral buoyancy pressure, free-swimming farmed cod would expose themselves to. Classical reward conditioning was used to motivate cod that were neutrally buoyant at 2?C3.3 ATM (10?C23 m depth) to respond to a sound signal by swimming rapidly upwards to a feeding station positioned at 1.5 ATM (5 m depth). Sixteen cod were implanted with data storage tags (DSTs) that registered their ambient pressure throughout the experiment. The DST data showed that cod voluntarily stopped rapid ascents before they reached the feeding station at an average maximum pressure reduction of about 41% relative to their neutral buoyancy pressure. This was equivalent to a 70% swimbladder expansion relative to neutral volume. During the experiment, cod seldom remained above their neutral buoyancy depths, except when feeding, indicating a behavioural aversion to positive buoyancy. To avoid the loss of buoyancy control in cod, we conclude that single lifting events of sea-cages, which forces swimbladder expansion, should never exceed a 70% expansion of the swimbladder above the pre-existing neutral buoyancy volume.     

Phosphorus forms as affected by abandoned anthills (Formica polyctena Förster) in forest soils: sequential extraction and liquid-state 31P-NMR spectroscopy

Ants are known to concentrate phosphorus (P) inside their nests via collection of food and litter. To elucidate the possible effects on long-term availability of soil P, five anthills abandoned by Red wood ant (Formica polyctena Förster) > 5—20 years ago were characterized for soil P forms in a temperate Danish deciduous forest. Sequentially extracted P fractions and liquid-state ³¹P nuclear magnetic resonance (NMR) spectra were obtained on surface samples (0—10 cm) from abandoned anthills and adjacent topsoil; in addition one representative soil profile in an abandoned anthill was investigated. The results show that different inorganic and all organic P fractions were enriched by a factor of 2.0—3.3 inside anthills relative to the surrounding soil. The soil underneath the abandoned anthill had higher P contents until 50-cm depth. Phosphorus composition was less affected by former anthill construction. Only the younger anthills revealed a preferential accumulation of labile organic P forms such as Na-HCO₃ extractable P or diester P. The accumulation of the stable and moderate labile P forms, however, persisted for ≥ 20 years after abandonment. We concluded that former ant activity enhanced long-term P availability of soil due to high local P inputs, whereas changes of the P form distribution lasted 5—10 years after nest abandonment.