Determination of plasma lysosomal enzyme activity and its relationship to severity of injury following blunt vehicular trauma in dogs

Objective: To determine plasma β‐d ‐glucuronidase (βG) activity in the first 4 hours following injury in dogs struck by a motor vehicle, and to evaluate whether the degree of enzyme activity is correlated with the severity of injury. Design: A prospective clinical study. Setting: Veterinary Medical Teaching Hospital. Animals: Thirteen client‐owned dogs that were presented to the Veterinary Hospital of the University of Pennsylvania between June and August 1999 for blunt vehicular trauma. Ten healthy student and staff‐owned dogs served as controls. Interventions: None. Measurements: Plasma was analyzed for βG enzyme activity at the time of presentation (n=13), and 1 and 4 hours (n=7) following presentation to the Emergency Service for blunt vehicular trauma. The results were compared with enzyme activity from healthy controls evaluated serially over 4 hours. Fluorometric analysis using 96‐well microtiter plates was used to perform the enzyme assays. The relationships between presentation (n=13) and 4 hours (n=7) of enzyme activity and 3 indices of metabolic and physical disturbance (serum pH, serum lactate and Animal Trauma Triage (ATT) score) at the time of presentation were also investigated. Main results: Of the 13 dogs, 7 fulfilled the inclusion criteria for comparison of enzyme activity of the trauma over time. A statistically significant difference in βG activity was found in the trauma group (mean 75.6±10.4 U) at 4 hours following presentation compared with controls (mean 48.0±6.4 U). This difference was suggested by 1 hour following presentation (trauma group, mean 70.4±10.9 U; control group, mean 49.8±5.5 U), although it did not reach statistical significance. Thirteen dogs fulfilled the inclusion criteria for comparison of only presentation enzyme activity with trauma severity score, serum lactate, and serum pH. No statistically significant relationship was found between the βd ‐glucuronidase activity and the presenting ATT score, serum lactate concentration, or serum pH at either presentation or 4 hours, although the power of these analyses was low. Conclusions: These results demonstrate that the activity of βG, a lysosomal enzyme, increases significantly in the systemic circulation in dogs 4 hours following blunt trauma. Additional research to include more severely injured dogs, a larger number of dogs, and to follow the course of injury for a longer period of time would be beneficial to further characterize βG activity following blunt trauma.     

Movement patterns of seaward migrating European eel (Anguilla anguilla) at a complex of riverine barriers: implications for conservation

River infrastructure such as weirs and hydropower stations commonly present migrating fish with multiple potential passage routes. Knowledge of the cues fish use to navigate such environments is required to protect migrants from hazardous areas and guide them towards safe passage; however, this is currently lacking for many species. Employing high‐resolution positioning telemetry, this study examined movements of downstream migrating adult European eel, Anguilla anguilla, as they encountered a complex of water control structures in one location on the River Stour, southern England. The distribution of eels across five potential routes of passage differed from that predicted based on proportion of discharge alone. Certain routes were consistently avoided, even when the majority of flow passed through them. Passage distribution was partially explained by avoidance in the vicinity of a floating debris boom. Movement paths were nonrandomly distributed across the forebay and eels moved predominantly within a zone 2–4 m from the channel walls. Understanding of avoidance and structure oriented movementation exhibited by eels will help advance effective guidance and downstream passage solutions for adults.     

Abnormal bone mineralization in a puppy fed an imbalanced raw meat homemade diet diagnosed and monitored using dual-energy X-ray absorptiometry

A 4-month-old male Old English Sheepdog was presented for evaluation of a raw meat-based homemade diet after a 1-month history of progressive lameness. Marked dietary deficiencies were detected, which included calcium, phosphorus and vitamin D. Hypovitaminosis D and hypocalcaemia were diagnosed by serum analysis. Evidence of severe diffuse osteopenia was noted on survey radiographs. Dual-energy X-ray absorptiometry (DEXA) was used to quantify bone mineral content and density and compare to published reference ranges. The puppy's initial bone mineralization was markedly subnormal, with bone mineral density 66% lower than expected, and bone mineral content 40% lower than expected. Subsequent DEXA scans were performed at intervals during the puppy's recovery to document the rate of bone re-mineralization and guide therapeutic recommendations. Marked improvement was achieved within 4 months through exercise control and feeding of a diet appropriately formulated for large breed puppy growth and development. This report reinforces the necessity of thorough dietary history and highlights the potential for malnutrition in pets fed homemade and raw meat-based diets. Use of DEXA has rarely been reported in clinical cases, yet can be a valuable tool for diagnosing and monitoring cases with abnormal bone mineralization. Further studies using DEXA to track bone mineralization in healthy puppies are encouraged to develop a more robust reference range of bone mineralization in growing dogs of varying sizes, weights and ages.     

Discovery of a synergistic effect of oxytocin on the efficacy of Alpha-Chloralose,a drug used for capturing and controlling birds

Overdose and death of both target and non-target species are not uncommon when α–chloralose is used for animal control. Alpha–chloralose appears to depress the central nervous system by having an affect on the GABA-A receptor in a manner similar to ethanol. Recently central administration of oxytocin was shown to block ethanol-induced impairment in rodents. Our study investigates whether IM administration of oxytocin speeds avian recovery from α–chloralose and reduces mortality under simulated field conditions. We found that when injected twice with oxytocin (30 uL/kg) chickens entered α–chloralose narcosis more quickly and showed greater behavioral impairment. When fed the LD₅₀ dose of α–chloralose, repeated injection with oxytocin produced no significant difference in mortality rate or time to death in comparison to the control group. The effects of peripheral oxytocin on female chicks were different than results found previously in cockerels given oxytocin centrally. Oxytocin is not a suitable antidote for α–chloralose overdose during animal capture in the field but instead accentuates α–chloralose narcosis, making capture more likely and efficient.     

The Arizona Water Settlement Act and urban water supplies

The 2004 Arizona Water Settlements Act (AWSA 2004) when implemented will allocate to two Native American tribes, the Gila River Indian Community (GRIC) and the Tohono O’odham Nation (TON) almost ten percent of Arizona’s total developed water supply, which is 7.04 million acre-feet a year. The successful passage of AWSA, given the scale of the water rights settlement and competing uses for finite water supplies, is the topic of this paper. Key motivations for the settlement are that: (1) the 653,500 acre-feet a year allocation is around a third of the GRIC’s Gila River Adjudication 2001 claim; (2) the GRIC signed a number of water leases and exchanges providing water to municipalities and has not ruled out signing more; and (3) AWSA resolved more than tribal water claims; it also settled thorny issues of Central Arizona Project (CAP) debt repayment (for $2 billion in construction costs) and division of water allocation between federal (Indian) and state (non-Indian) uses including the reallocation of high priority uncontracted CAP water to cities.     

Inter‐specific variability in organic nitrogen uptake of three temperate grassland species

We tested the inter‐specific variability in the ability of three dominant grasses of temperate grasslands to take up organic nitrogen (N) in the form of amino acids in soils of differing fertility. Amino acid uptake was determined by injecting dual labeled glycine‐2‐¹³C‐¹⁵N into the soil, and then measuring the enrichment of both ¹³C and ¹⁵N in plant tissue after 50 hours. We found enrichment of both ¹³C and ¹⁵N in root and shoot material of all species in both soils, providing first evidence for direct uptake of glycine. We show that there was considerable inter‐specific variability in amino acid uptake in the low fertility soil. Here, direct uptake of amino acid was greater in the grass Agrostis capillaris, which typically dominates low fertility grassland, than Lolium perenne, which inhabits more fertile sites. Direct uptake of amino acid for Holcus lanatus. was intermediate between the above two species. Unlike in the low fertility soil, there was no difference in uptake of either ¹³C or ¹⁵N by grasses in the high fertility soil, where uptake of mineral N is thought to be the major mechanism of N uptake of these grasses. Overall, our findings may contribute to our understanding of differences in competitive interactions between grasses in soils of different fertility status.     

Dissolved organic matter leaching in some contrasting New Zealand pasture soils

Leaching of dissolved organic matter (DOM) from pastoral soils is increasingly seen as an important but poorly understood process. This paper examined the relationship between soil chemical properties, microbial activity and the losses of dissolved organic carbon (DOC) and nitrogen (DON) through leaching from six pasture soils. These soils differed in carbon (C) (4.6–14.9%) and nitrogen (N) (0.4–1.4%) contents and in the amount of organic C and N that had accumulated or been lost in the preceding 20+ years (i.e. −5131 to +1624 kg C ha⁻¹ year⁻¹ and −263 to +220 kg N ha⁻¹ year⁻¹, respectively). The paper also examined whether between‐soil‐type differences in DOC and DON leaching was a major explanatory factor in the observed range of soil organic matter (SOM) changes in these soils. Between 280 and 1690 kg C ha⁻¹ year⁻¹ and 28–117 kg N ha⁻¹ year⁻¹ leached as DOC and DON, respectively, from the six soils in a lysimeter study, with losses being greater from two poorly drained gley soils. Losses of C and N of this magnitude, while at the upper end relative to published data, could not fully explain the losses at Rawerawe, Bruntwood and Lepperton sites reported by Schipper et al. (2007) . The study highlights the leaching of DOM as a significant pathway of loss of C and N in pasture soils that is often ignored or given little attention in predictive models and nutrient budgeting. Leaching losses of DOC and DON alone, or in combination with slightly increased respiration losses of SOM given a 0.2°C increase in the mean annual soil temperature, do not fully explain long‐term changes in the SOM observed at these sites. When soils examined in the present study were separated on the basis of drainage class, the losses of DOC by leaching were correlated with both total and hot‐water extractable C (HWC), the latter being a measure of the labile SOM fraction. Basal microbial CO₂ respiration rates, which varied between 1 and 3.5 µg CO₂‐C g⁻¹ soil hour⁻¹ in surface soils (0–75‐mm depth), was also linked to HWC and the quantities of C lost as DOC. Adoption of the HWC method as an approach that could be used as a proxy for the direct measurement of the soil organic C lost by leaching as DOC or respired needs to be examined further with a greater number of soils. In comparison, a poor relationship was found between the hot‐water extractable N (HWN) and loss of DON by leaching, despite HWN previously being shown to be a measure of the mineralizable pool of N in soils, possibly reflecting the greater competition for N than C in these soils.     

Feline herpesvirus

Feline herpesvirus (FHV-1; felid herpesvirus 1 (FeHV-1)) is an alphaherpesvirus of cats closely related to canine herpesvirus-1 and phocine herpesvirus-1. There is only one serotype of the virus and it is relatively homogenous genetically. FeHV-1 is an important cause of acute upper respiratory tract and ocular disease in cats. In addition, its role in more chronic ocular disease and skin lesions is increasingly being recognised. Epidemiologically, FeHV-1 behaves as a typical alphaherpesvirus whereby clinically recovered cats become latently infected carriers which undergo periodic episodes of virus reactivation, particularly after a stress. The primary site of latency is the trigeminal ganglion. Conventional inactivated and modified-live vaccines are available and protect reasonably well against disease but not infection, although viral shedding may be reduced. Genetically engineered vaccines have also been developed, both for FeHV-1 and as vector vaccines for other pathogens, but none is as yet marketed.