Global conservation status and research needs for tarpons (Megalopidae), ladyfishes (Elopidae) and bonefishes (Albulidae)

We assessed the taxonomic diversity, geographic distributions, life history, ecology and fisheries of tarpons, ladyfishes and bonefishes (members of the subdivision Elopomorpha), which share many life history and habitat use characteristics that make them vulnerable to environmental and anthropogenic stresses in coastal environments. This assessment of Red List status for the International Union for the Conservation of Nature reveals three species considered near threatened or vulnerable, three species of least concern, and 11 data‐deficient species. Although the taxonomy of tarpons appears stable, it is less so for ladyfishes and bonefishes. In aggregate, these species are distributed circumtropically and foray into temperate zones. Although they spawn in marine habitats, larvae of many species disperse into estuarine habitats, which are declining in area or degrading in quality. Several species support high‐value recreational fisheries, or culturally important small‐scale commercial and artisanal fisheries. Nonetheless, no formal stock assessment exists for any species, so improved data collection, information sharing and assessment techniques should facilitate socio‐economic development of individual fisheries. Catch‐and‐release recreational fisheries that promote conservation of tarpon and bonefishes in some regions are promising models to improve the conservation status of these fishes elsewhere, as well as the economic development of these fishing communities. Most tarpons, ladyfishes and bonefishes likely face significant challenges from anthropogenically mediated habitat loss and alteration, and several are vulnerable to both habitat degradation and overfishing. Broader protection and enhancements to fisheries habitat in all regions will benefit these as well as many other coastal fishery species.     

Case–control study of Staphylococcus lugdunensis infection isolates from small companion animals

Background – Coagulase‐negative Staphylococcus lugdunensis has recently been shown to cause invasive infections of people, which are similar in pathogenic effect to those caused by Staphylococcus aureus. Little is known about the pathogenicity of S. lugdunensis in companion animals. Objectives – To compare potential risk factors for infection, body sites affected, and whether cases and controls had been treated with antimicrobial drugs based upon susceptibility test results. Animals – Thirty‐three cases of S. lugdunensis infection (25 dogs, six cats and two small mammals) were identified between January 2003 and August 2011. Two Staphylococcus pseudintermedius controls, which were identified by the microbiology laboratory immediately before and after each S. lugdunensis case, were host‐species matched to each case. Methods – A retrospective case–control analysis. Results – During the period evaluated, the prevalence of S. lugdunensis infection was 1.3 cases per 10,000 hospital admissions for dogs and 0.95 cases per 10,000 admissions for cats (P = 0.453). In univariate analyses, S. pseudintermedius isolation was significantly associated with skin infections (P < 0.0001), while S. lugdunensis isolation was associated with the respiratory tract (P = 0.03) and other deep tissues (P = 0.005). Cases were less likely than controls to have been treated based upon susceptibility test results (P = 0.02). A conditional logistic regression analysis showed isolation of S. lugdunensis to be associated with recent (≤ 30 days) steroid administration (odds ratio, 17.72; 95% confidence interval, 2.35–132.82; P = 0.005); and in‐patient status (odds ratio, 9.67; 95% confidence interval, 2.18–42.88; P = 0.003). Conclusions – These results suggest that S. lugdunensis may cause invasive infections in companion animals, which should be treated with antimicrobials based upon susceptibility tests when available.     

Molecular diversity of methanogens in fecal samples from Bactrian camels (Camelus bactrianus) at two zoos

Animals are dependent on mutualistic microbial communities that reside in their gastrointestinal track for essential physiological functions such as nutrition and pathogen resistance. The composition of microbial communities in an animal is influenced by various factors, including species, diet and geographical location. In this preliminary study, the population structure of fecal methanogens in Bactrian camels (Camelus bactrianus) from two zoos was studied using separate 16S rRNA gene libraries for each zoo. While methanogen sequences belonging to the genus Methanobrevibacter were dominant in both libraries, they showed significant differences in diversity (p=0.05) and structure (p<0.0001). Population structure analysis revealed that only two operational taxonomic units (OTUs) were shared between libraries, while two OTUs were unique to the Southwick Zoo library and seven OTUs were unique to the Potter Park Zoo library. These preliminary results highlight how methanogen population structures can vary greatly between animals of the same species maintained in captivity at different locations.     

Renal effects of carprofen and etodolac in euvolemic and volume-depleted dogs

Objective-To determine the effects of carprofen and etodolac on renal function in euvolemic dogs and dogs with extracellular fluid volume depletion induced via administration of furosemide. Animals-12 female Beagles. Procedures-Dogs received a placebo, furosemide, carprofen, etodolac, furosemide and carprofen, and furosemide and etodolac. The order in which dogs received treatments was determined via a randomization procedure. Values of urine specific gravity, various plasma biochemical variables, glomerular filtration rate (GFR [urinary clearance of creatinine]), and renal plasma flow (urinary clearance of para-aminohippuric acid) were determined before and after 8 days of drug administration. A washout time of approximately 12 days was allowed between treatment periods. Results-Administration of furosemide, furosemide and carprofen, and furosemide and etodolac caused changes in urine specific gravity and values of plasma biochemical variables. Administration of carprofen or etodolac alone did not have a significant effect on renal plasma flow or GFR. Concurrent administration of furosemide and carprofen or furosemide and etodolac caused a significant decrease in GFR. After 12-day washout periods, mean values of GFR were similar to values before drug administration for all treatments. Conclusions and Clinical Relevance-Results indicated GFR decreased after 8 days of concurrent administration of furosemide and carprofen or furosemide and etodolac to dogs. Administration of preferential cyclooxygenase-2 inhibitors to dogs with extracellular fluid volume depletion or to dogs treated with diuretics may transiently impair renal function.     

A reliable and non-destructive method for estimating forage shrub cover and biomass in arid environments using digital vegetation charting technique

Despite the importance of fodder shrubs to small ruminant diets and production in arid and semi-arid ecosystems, they are often not considered when quantifying grazing land potential. This oversight is mainly due to the time consuming and costly traditional techniques used to estimate shrub biomass. The shrub fodder component should be measured to avoid underestimation of the carrying capacity of rangelands. In this study, we present a fast, reliable and non-destructive method to estimate canopy vegetation cover to obtain aboveground shrub biomass. The experiment was conducted under field conditions in northwest Syria, where seedlings of seven shrub species were monitored for one year: Atriplex leucoclada (Moq.) Boiss., A. halimus L., A. lentiformis (Torr.) S. Watson, A. canescens (Pursh) Nutt., A. nummularia Lindl., Salsola vermiculata L. and Haloxylon aphyllum (C.A. Meyer) Bunge. The experimental layout was a randomized complete block design with five replications. We explored the effectiveness of digital vegetation charting technique (DVCT) for estimating shrub canopy cover. Aboveground shrub biomass was clipped to estimate the dry matter (DM) weight per species and to determine its relationship to canopy cover. In this study, an estimate of greenness (percent green vegetation cover) was extracted by way of greenness algorithms. Simple linear regressions between vegetation cover and biomass for 210 plots were performed. The cover of the seven species differed (P < 0.01): A. leucoclada had the highest vegetation cover (56%) and H. aphyllum the lowest (7%). Vegetation cover and DM biomass were positively correlated (P < 0.01) with R-squared ranging from 0.66 (H. aphyllum) to 0.84 (S. vermiculata). Our method provided reasonable estimations of canopy coverage which could predict aboveground phytomass. We conclude that DVCT offers a rapid, reliable and consistent measurement of shrub cover and biomass provided that shrubs have open architecture. This study shows the potential of digital cameras and image processing to determine cover/biomass in a non-destructive, timely and cost efficient way.     

Do plant species with different growth strategies vary in their ability to compete with soil microbes for chemical forms of nitrogen?

We used dual labelled stable isotope (¹³C and ¹⁵N) techniques to examine how grassland plant species with different growth strategies vary in their ability to compete with soil microbes for different chemical forms of nitrogen (N), both inorganic and organic. We also tested whether some plant species might avoid competition by preferentially using different chemical forms of N than microbes. This was tested in a pot experiment where monocultures of five co-existing grassland species, namely the grasses Agrostis capillaris, Anthoxanthum odoratum, Nardus stricta, Deschampsia flexuosa and the herb Rumex acetosella, were grown in field soil from an acid semi-natural temperate grassland. Our data show that grassland plant species with different growth strategies are able to compete effectively with soil microbes for most N forms presented to them, including inorganic N and amino acids of varying complexity. Contrary to what has been found in strongly N limited ecosystems, we did not detect any differential uptake of N on the basis of chemical form, other than that shoot tissue of fast-growing plant species was more enriched in ¹⁵N from ammonium-nitrate and glycine, than from more complex amino acids. Shoot tissue of slow-growing species was equally enriched in ¹⁵N from all these N forms. However, all species tested, least preferred the most complex amino acid phenylalanine, which was preferentially used by soil microbes. We also found that while fast-growing plants took up more of the added N forms than slow-growing species, this variation was not related to differences in the ability of plants to compete with microbes for N forms, as hypothesised. On the contrary, we detected no difference in microbial biomass or microbial uptake of ¹⁵N between fast and slow-growing plant species, suggesting that plant traits that regulate nutrient capture, as opposed to plant species-specific interactions with soil microbes, are the main factor controlling variation in uptake of N by grassland plant species. Overall, our data provide insights into the interactions between plants and soil microbes that influence plant nitrogen use in grassland ecosystems.     

Use of high-resolution ultrasound as a diagnostic tool in veterinary ophthalmology

The recent development of a 20-MHz, high-frequency ultrasound probe has allowed tissue to be visualized at resolutions of 20 to 80 microm, which is similar to a low-power histologic view. This high degree of resolution, however, limits tissue penetration to 5 to 10 mm, which is ideal for examination of the anterior segment of the eye. The detail provided by high-resolution ultrasound readily permits the clinician to distinguish between various anterior segment entities that may appear similar but are treated quite differently, such as anterior uveal tumors, iridociliary cysts, and iris bombé. High-frequency ultrasound is also a valuable aid in creating a surgical plan for treatment of ocular disorders in which the cornea is opaque, such as feline corneal sequestrum and tumor invasion into the cornea. Other applications of this technology include elucidation of the pathogenesis of glaucoma in veterinary patients and evaluation of regions of the lens that are difficult to examine directly.     

Establishment of persistent avian infectious bronchitis virus infection in antibody-free and antibody-positive chickens

Avian infectious bronchitis virus (IBV) causes a highly contagious and economically significant disease in chickens. Establishment of a carrier state in IBV infection and the potential for the persistent virus to undergo mutations and recombination in chicken tissues have important consequences for disease management. Nevertheless, whether chickens can maintain persistent IBV infection in the absence of reinfection from exogenous sources or the presence of antibody in the host can modulate virus persistence remains unclear. Indeed, whether or not IBV genome can undergo genetic changes during in vivo infection has not been demonstrated experimentally. In the present study, IBV shedding and tissue persistence were monitored in individual chickens maintained under strict isolation that precluded reinfection from exogenous sources. In the first of two experiments, intranasal exposure of 6-wk-old antibody-free chickens to IBV vaccine virus resulted in intermittent shedding of the virus from both trachea and cloaca of individual birds for up to 63 days. Also, the virus was recovered from the internal organs (spleen, gonad, kidney, lung, cecal tonsil, and cloacal bursa) of six of eight birds killed at various intervals between 27 and 163 days postinoculation (DPI). In the second experiment, IBV exposure of 1-day-old maternal antibody-positive chicks led to periodic virus shedding from the trachea and cloaca in all chickens until 77 days; however, internal organs (lungs and kidneys) of only one of seven birds (killed at 175 DPI) were virus positive, suggesting that presence of antibody at the time of infection protects internal organs from IBV infection. When the lung and kidney isolates of IBV from the latter experiment were compared with the parent-vaccine virus, no changes in their antigenicity, tissue tropism, or the nucleotide sequence of the S1 glycoprotein gene were observed. These findings indicate that, unlike the mammalian coronaviruses, propensity for frequent genetic change may not be inherent in the IBV genome.     

Plasma concentrations of tumor necrosis factor-alpha in cats with congestive heart failure

OBJECTIVE: To determine whether plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) are increased in cats with congestive heart failure (CHF) secondary to cardiomyopathy. ANIMALS: 26 adult cats with CHF and cardiomyopathy and 9 healthy control cats. PROCEDURE: Plasma concentrations of TNF-alpha were measured in cats with CHF and cardiomyopathy. Tumor necrosis factor-alpha was measured by quantifying cytotoxic effects of TNF-alpha on L929 murine fibrosarcoma cells. RESULTS: Concentrations of TNF-alpha were increased (0.13 to 3.6 U/ml) in 10 of 26 cats with CHF but were undetectable in the other 16 cats with CHF and all control cats. In 20 of 26 cats with CHF right-sided heart failure (RHF) was evident; TNF-alpha concentrations were increased in 9 of these 20 cats. The remaining 6 cats had left-sided heart failure (LHF); TNF-alpha concentrations were increased in only 1 of these cats. Age of cats with LHF (mean +/- SD, 12.1+/-6.2 years) was not significantly different from age of the cohort with RHF (10.5+/-5.2 years). Body weight of cats with increased TNFalpha concentrations (5.4+/-1.8 kg) was not significantly different from body weight of cats with CHF that did not have measurable concentrations of TNF-alpha (4.7+/-1.6 kg). CONCLUSIONS AND CLINICAL RELEVANCE: Concentrations of TNF-alpha were increased in many cats with CHF. Cats with RHF were most likely to have increased TNF-alpha concentrations. Increased plasma concentrations of TNF-alpha in cats with CHF may offer insights into the pathophysiologic mechanisms of heart failure and provide targets for therapeutic interventions.