Medetomidine/midazolam/ketamine anaesthesia in ferrets: effects on cardiorespiratory parameters and evaluation of plasma drug concentrations

ObjectiveTo evaluate the cardiorespiratory effects and plasma concentrations of medetomidine-midazolam-ketamine (MMK) combinations administered by intramuscular (IM) or subcutaneous (SC) injection in sable ferrets (Mustela putorius furo).Study designProspective randomized experimental study.AnimalsEighteen adult ferrets: weight median 1.19 (range 0.81–1.60) kg.MethodsAnimals were allocated to one of three groups: group IM07 received 20 μg kg^?1 medetomidine, 0.5 mg kg^?1 midazolam and 7 mg kg^?1 ketamine IM; group IM10 20 μg kg^?1 medetomidine, 0.5 mg kg^?1 midazolam and 10 mg kg^?1 ketamine IM; and group SC10 20 μg kg^?1 medetomidine, 0.5 mg kg^?1 midazolam and 10 mg kg^?1 ketamine SC. Following instrumentation, cardiorespiratory parameters and plasma drug concentrations were measured every 5 minutes (T5–T30) for 30 minutes Ferrets were then euthanased. Data were analysed using anova for repeated measures. p < 0.05 was considered significant.ResultsResults are mean ± SD. Induction of anaesthesia (minutes) in IM07 and IM10 [2 (1)] was significantly faster than in SC10 [5 (2)]. All groups demonstrated the following: results given as groups IM07, IM10 and SC10 respectively. Mean arterial blood pressures (mmHg) were initially high [186 (13); 174 (33) and 174 (9) at T5] but decreased steadily. Pulse rates were initially 202 (20), 213 (17) and 207 (33) beats minute^?1, decreasing with time. PaO₂ (mmHg) was low [54.0 (8), 47.7 (10) and 38.5 (1)] at T5, although in groups IM07 and IM10 it increased over time. Plasma concentrations of all drugs were highest at T5 (36, 794 and 8264 nmol L^?1 for medetomidine, midazolam and ketamine, respectively) and decreased thereafter: for both midazolam and ketamine, concentrations in IM07 and IM10 were higher than SC10.Conclusions and clinical relevanceMMK combinations containing either 7 or 10 mg kg^?1 ketamine and given IM are suitable combinations for anaesthetising ferrets, although the observed degree of hypoxaemia indicates that oxygen administration is vital.     

Some factors causing mortality among female minks during the puerperium and lactation periods.

The purpose of this study, in which the farm was used as the statistical unit, was to find factors affecting mink mortality under farm conditions. Mortality was hypothesised to be affected by factors including, among others, variables describing the amount (level) and variation in composition and quality of the feed. Other explanatory variables applied in the study included farm size and age. Factor analyses were performed for variables of feed composition and quality in order to condense the variable information and to facilitate the selection of explanatory variables. This report presents a preliminary regression model for female mink mortality factors describing feed level and variation, and farm size, as explanatory variables. The regression model emphasized among other factors the importance of a constant albumin quality and a constant energy level.     

Ion neutral mass spectrometer results from the first flyby of Titan

The Cassini Ion Neutral Mass Spectrometer (INMS) has obtained the first in situ composition measurements of the neutral densities of molecular nitrogen, methane, molecular hydrogen, argon, and a host of stable carbon-nitrile compounds in Titan's upper atmosphere. INMS in situ mass spectrometry has also provided evidence for atmospheric waves in the upper atmosphere and the first direct measurements of isotopes of nitrogen, carbon, and argon, which reveal interesting clues about the evolution of the atmosphere. The bulk composition and thermal structure of the moon's upper atmosphere do not appear to have changed considerably since the Voyager 1 flyby.     

Matrix composition and corridor function for austral thrushes in a fragmented temperate forest

Although it is widely recognized that animal movement may be facilitated by corridors and hindered by the matrix, the influence of matrix composition on the use of corridors still remain poorly understood. We used translocation experiments and state-space models to assess if the movement response of the frugivorous bird, the austral thrush, to riparian forest strips varies depending on matrix composition (open pasture vs. eucalyptus plantation). In agricultural landscapes, the directions displayed by most birds when moving in the open pasture matrix were consistent with an edge-following behavior. Riparian strips also functioned as passive drift fences in agricultural landscapes, with strips being used as conduits for movements once birds entered into a riparian strip. Our results suggest that visual perception of riparian strips by birds is hampered by the complex habitat structure in the eucalyptus matrix and that the use of riparian strips as habitat is conditioned by the surrounding matrix.     

Comparative examination of the lateral cerebral ventricles of different dog breeds using quantitative computed tomography

Due to the great variations among the shape of the skull in different breeds, the routine use of computed tomography in the diagnosis of central nervous diseases in the dog requires basic knowledge of the structure of the inner subarachnoidal spaces. In neoplastic as well as in inflammatory brain disease, changes of the size and shape of liquor filled spaces can be found. In the present study, the easily demonstrable lateral ventricles of the brain of ten dogs of each breed, respectively, without cerebral disease belonging to the breeds German Shepherd (DSH), Dachshund, Boxer, Labrador Retriever and Toy poodle were characterized with regard to their two-dimensional expansion. The average width and height of the lateral ventricles were ascertained for each breed.The Boxer had the relatively largest lateral ventricles, whereas in the other breeds,their sizes were very similar. 32 of the dogs investigated (64%) had symmetric lateral ventricles, and in 18 dogs (36%) they were asymmetric. Of these 18 cases, the left lateral ventricle was larger in 12 dogs (67%).     

Seasonal acclimation of photosystem II in Pinus sylvestris. I. Estimating the rate constants of sustained thermal energy dissipation and photochemistry

Acclimation of the partitioning of absorbed light energy in Photosystem II (PSII) between photochemical and non-photochemical processes includes short-term adjustments that are rapidly reversed in the dark and seasonal acclimation processes that are unaffected by dark acclimation. Thus, by using dark-acclimated leaves to study the seasonal acclimation of PSII, the confounding effect of short-term adjustments is eliminated. The maximum quantum yield of photochemistry, estimated by chlorophyll fluorescence analysis as F(v)/F(m), where F(v) = (F(m) - F(o)), and F(m) and F(o) are maximum and minimum chlorophyll fluorescence, respectively, has been widely used to follow the seasonal acclimation of PSII, because it is measured in dark-acclimated leaves. Seasonal changes in F(v)/F(m) can be caused by adjustments in either the photochemical capacity in PSII, or the capacity of thermal dissipation in PSII, or both. However, there is a lack of chlorophyll fluorescence parameters that can distinguish between these processes. In this study, we introduce two new parameters: the rate constants of sustained thermal energy dissipation (k(NPQ)) and of photochemistry (k(P)). We estimated k(NPQ) and k(P) from dark-acclimated F(o) and F(m) measured during spring recovery of photosynthesis in Scots pine (Pinus sylvestris L.) trees. We suggest that k(NPQ) and k(P) be used to study the mechanisms underlying the observed seasonal acclimation in PSII, because these parameters provide quantitative data that complement and extend F(v)/F(m) measurements.     

Comparative motion analysis of the canine hind limb during gait on force plate and treadmill

Computer assisted gait analysis allows for the objective examination of ground reaction forces as well as the kinematic analysis of gait. At present it is unclear if there are relevant differences in the gait pattern of the hind limb of dogs during the walk on treadmill and force plate. Thus, aim of this study was the comparison of canine hind limb joint angles and certain kinematic gait cycle parameters like cadence, step and stride time as well as step length during the walk on force plate and treadmill. 19 adult dogs of different breeds were analysed. Extension and flexion of hip, stifle and hock, hip ab- and adduction and range of motion (ROM) were evaluated. Furthermore joint angles at the moment of maximum load were identified. Considering the joint angles and gait cycle parameters there were no significant differences between force plate and treadmill, except for the hip angles, the hock angle at the moment of maximum load as well as for cadence and stride time. Whereas all flexion/extension joint angles, except the maximum hock joint angle, showed a moderate to good correlation, the ROM of the analysed joint angles was in maximum moderate. In summary it could be demonstrated that the gait pattern of the canine hind limb shows similarities on force plate and treadmill. Nevertheless significant differences of certain parameters exist and in total only a fair to moderate correlation of the data between treadmill and force plate could be shown. Therefore the results of this study provide important information for the comparative interpretation of canine gait analysis carried out on force plates and treadmills.     

Organic carbon sequestration in earthworm burrows

Earthworms strongly affect soil organic carbon cycling. The aim of this study was to determine whether deep burrowing anecic earthworms enhance carbon storage in soils and decrease C turnover. Earthworm burrow linings were separated into thin cylindrical sections with different distances from the burrow wall to determine gradients from the burrow wall to the surrounding soil. Organic C, total N, radiocarbon (¹⁴C) concentration, stable isotope values (δ¹³C, δ¹⁵N) and extracellular enzyme activities were measured in these samples. Anecic earthworms increased C stocks by 270 and 310 g m^?2 accumulated in the vertical burrows. C-enrichment of the burrow linings was spatially highly variable within a distance of millimetres around the burrow walls. It was shown that C accumulation in burrows can be fast with C sequestration rates of about 22 g C m^?2 yr^?1 in the burrow linings, but accumulated C in the burrows may be mineralised fast with turnover times of only 3–5 years. Carbon stocks in earthworm burrows strongly depended on the earthworm activity which maintains continuous C input into the burrows. The enhanced extracellular enzyme activity of fresh casts was not persistent, but was 47% lower in inhabited burrows and 62% lower in abandoned burrows. Enzyme activities followed the C concentrations in the burrows and were not further suppressed due to earthworms. Radiocarbon concentrations and stable isotopes in the burrow linings showed an exponential gradient with the youngest and less degraded organic matter in the innermost part of the burrow wall. Carbon accumulation by anecic earthworm is restricted to distinct burrows with less influence to the surrounding soil. Contrary to the initial hypothesis, that organic C is stabilised due to earthworms, relaxation time experiments with nuclear magnetic resonance spectroscopy (NMR) did not reveal any enhanced adsorption of C on iron oxides with C stabilising effect. Our results suggest that earthworm activity does not substantially increase subsoil C stocks but burrows serve as fast ways for fresh C transport into deep soil horizons.     

Sexual maturity and egg production in an unexploited population of the red squat lobster Pleuroncodes monodon (Decapoda,Galatheidae) from Central America

The squat lobster Pleuroncodes monodon is one of the most common and abundant galatheid species in the deepwater fishery of Pacific coast of America. In contrast with Peru and Chile, the red squat lobster is not commercially exploited in Costa Rica. Here we estimated the size of sexual maturity and analysed egg production in P. monodon from the Pacific of Costa Rica; the results might be important for an adequate management strategy when initiating a sustainable fishery of this resource in Costa Rica. Analyses of allometric growth revealed that females and males reached their morphological sexual maturity at 26.9 and 30.4 mm CL, respectively. The percentage of immature females captured in the present study (54%) suggests that almost half of females are able to reproduce before they are caught. Egg production was positively correlated with body size; females that measured between 24.1 and 29.0 mm CL contributed roughly 90% to the offspring production of the population. Females from Costa Rica had a considerably lower average egg volume (0.039 mm³) and higher fecundity (9810) than females from Chile. In comparison to other American galatheids P. monodon from Costa Rica produces numerous but small eggs, a typical strategy of species with a prolonged larval development. An analysis between our results and information published about P. monodon from Chile also revealed differences in the size–frequency distribution shape of both populations. The non-exploited character of the Costa Rican P. monodon population and a latitudinal (temperature-related) cline in body size might be associated with these differences.