Using habitat models to determine conservation priorities for pond-breeding amphibians in a privately-owned landscape of northern Idaho, USA

As rural landscapes experience increasing levels of residential development, the persistence of species that rely on them will depend on informed planning and management decisions. An understanding of habitat requirements is essential for setting priorities and developing landscape-level plans for the survival of these species. In many temperate rural landscapes, artificially created ponds may be the only wetlands available for aquatic reproduction by amphibians. The introduction of non-native fish into these ponds reduces survival and prohibits successful reproduction of many native pond-breeding amphibians. We surveyed 105 randomly selected wetlands in a primarily privately-owned, rural landscape in north Idaho, USA, for pond-breeding amphibian larvae in 2004 and 2005. We used an information theoretic multimodel inference and an algorithmic (random forests) approach to model habitat for each species based on local and landscape characteristics. We also used a mail survey to quantify how landowners value fish in their wetlands and their plans for future wetland development and fish stocking. Sixty-seven percent of pond owners reported that fishing in their pond was at least slightly important to them and 36% of owners indicated that they were at least 50% likely to add fish to their ponds in the next 5-10 years. Landscape change predictions for this area indicate that forests will become more open due to thinning; habitat models indicated that this is likely to be detrimental to long-toed salamanders and beneficial to Pacific treefrogs. Habitat models also indicate that Columbia spotted frog breeding sites consist of wetlands on flat ground with high solar insolation and that this species is sensitive to nearby development, indicating that as this landscape becomes further developed, this species may require habitat protection for persistence.     

Pteridine pattern in the urine of swine of different breeds and halothane genotypes in relation to nutrition and stress]

Urinary pteridine patterns and creatinine concentrations were determined in pigs of the breeds Piétrain, Deutsche Landrasse and their crossbreds. Also the influence of the halothane genotypes, of different feeding and of treadmill exercise was examined. We conclude that creatinine concentration in pig urine is not a reliable reference parameter for the pteridine excretion. Creatinine values were significantly influenced by breed and feeding. The pteridine pattern of pigs' urine depends on the breed and correlates with other metabolic parameters. Stress is reflected by altered pteridine concentrations.     

Strangles in horse studs: Incidence, risk factors and effect of vaccination

A questionnaire survey of 179 horse studs in New South Wales was conducted to estimate the incidence of strangles during 1985 to 1988, to identify risk factors for strangles outbreaks and to assess the effect of strangles vaccination. Forty-nine of the studs (27.4%) had at least one strangles outbreak during this period and 62 studs (34.6%) had at least one case of strangles. The average incidence of strangles was 2.1 cases per 100 horses per year. The risk of strangles increased progressively with the total horse population and rose markedly when more than 100 mares had been served in the 1988-89 season. Certain types of feeders, fences and water sources were also significantly associated with outbreaks of strangles. Strangles vaccine was used on 63 studs (35.2%). Thirty-seven of these (58.7%) used the manufacturer's recommended vaccination regime. When other risk factors were taken into account, vaccination had no significant effect on the likelihood of a strangles outbreak.     

Application of phylogeny reconstruction and character-evolution analysis to inferring patterns of directional microbial transmission

I used phylogenetic analyses to reconstruct patterns of directional interspecific transmission during a pseudorabies virus outbreak in Illinois, USA, in 1989. Isolates were recovered from five species: cattle, sheep, goats, pigs, and raccoons (Procyon lotor). I generated DNA sequences for 16 isolates of pseudorabies virus at the glycoprotein C gene, from which I constructed phylogenetic trees. I then used these trees, in combination with parsimony-based analyses of character evolution, to infer the frequency and direction of interspecific transmission events. Comparing inferred frequencies and directions of transmission to null expectations based on 10,000 random trees indicated a significant excess of transmission events from pigs to pigs and a corresponding lack of transmission events from non-porcine species. These results are concordant with the know biology and natural history of pseudorabies virus, and they demonstrate that retrospective phylogeny reconstruction and analyses of character evolution can be used to investigate the transmission ecology of pathogens.     

Use of a high-molecular-weight carboxymethylcellulose in a tissue protective solution for prevention of postoperative abdominal adhesions in ponies

OBJECTIVE: To evaluate efficacy and safety of IP administration of high-molecular-weight carboxymethylcellulose (HMW CMC) for the prevention of postoperative intra-abdominal adhesions in ponies. ANIMALS: 10 ponies. PROCEDURE: A 1% solution of HMW CMC was instilled intra-abdominally prior to surgery in 5 ponies, whereas 5 control ponies did not receive HMW CMC. Postoperative adhesions were induced by use of a bowel-abrasion method comprising laparotomy, typhlotomy, and abrasion of jejunal serosa at multiple sites with placement of 3 sutures at each site. Day of surgery was day 0. After surgery, ponies were monitored, and hematologic, serum biochemical, and peritoneal fluid analyses were performed on days 1, 2, 3, 5, 7, and 10. On day 10, ponies were euthanatized. Intra-abdominal adhesions were recorded, and tissue samples were collected for histologic examination. RESULTS: A significantly greater number of adhesions, number of multiple adhesions, and mean incidence of adhesions were identified in control ponies, compared with CMC-treated ponies. Mean peritoneal fluid WBC count on day 7 and serum fibrinogen concentrations on days 5 and 7 were significantly higher in control ponies, compared with CMC-treated ponies. Results of serum biochemical analyses did not differ significantly between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: Intra-abdominal use of 1% HMW CMC during surgery was effective for preventing postoperative adhesions in ponies. Use of HMW CMC did not have detrimental effects on wound healing, intra-abdominal defenses, or patient health. A 1% solution of HMW CMC may be used routinely during abdominal surgery of horses for prevention of postoperative adhesions.     

Adaptation and limitations of established hemagglutination inhibition assays for the detection of porcine anti-swine influenza virus H1N2 antibodies.

Hemagglutination inhibition (HI) has been a reliable method for determining porcine antibody levels to the well-characterized swine influenza virus (SIV) H1N1 and H3N2 subtypes. However, the recent emergence of the novel H1N2 serotype of SIV and the persistence of 2 other serotypes (H1N1 and H3N2) in the United States swine population represents a significant challenge to diagnostics. Both standardized and modified HI protocols were used in a blinded study to examine a collection of 50 control sera representing a total of 12 swine that were experimentally inoculated with one of the 3 SIV subtypes. Using these control sera data, a statistical basis for analysis was established in an attempt to classify 30 field sera with known case histories or seroprevalance into SIV serotype categories. By this approach 57% of the field sera could be classified into specific categories. The remaining samples that could not be classified reliably were most likely composed of heterogeneous anti-SIV antibody populations. These results indicate that although serological differentiation might be possible in a controlled environment, applications of these methods to field samples are currently problematic. Approaches other than HI will be required to fulfill the current need for SIV diagnostics and surveillance when specific serotype identification is required.     

Pharmacokinetics of hemoglobin-based oxygen carrier hemoglobin-glutamer-200 bovine (oxyglobin) in the horse

Oxyglobin (OXY) is a hemoglobin‐based oxygen carrier (HBOC) made of glutaraldehyde‐polymerized bovine hemoglobin (bHb). Products similar to OXY are under development for use as temporary blood substitutes in trauma, shock and anemia. Since they all may increase blood O₂‐carrying capacity and thus, possibly tissue oxygenation, they may also be used to enhance performance of both equine and human athletes. That is why HBOCs are banned from use in athletic competition. Our goal was to determine the pharmacokinetics of OXY after intravenous (IV) infusion to horses. Blood and urine samples were collected from adult horses that received an IV dose of 32.5 g of OXY. Concentrations of OXY in plasma and urine were quantified using a newly developed LC/Q‐TOF‐MS/MS detection technique. Level of quantification (LOQ) was 50 μg mL^–1. The decline of the plasma concentration‐time curve of the HBOC was described by a 2‐compartment model (C1 and C2). The median distribution alpha (t1/2k1,0) and elimination beta (t1/2k2,0) half‐lives were 1.3 and 12.0 hours, respectively. The bHb molecules in OXY are not of uniform size and vary substantially in molecular weight (MW). Of the OXY molecules 53% were eliminated in C1, which represented the smaller MW molecules and 47% in C2, which represented the larger MW bHb. The maximal 0‐time plasma concentration was 662.0 μg/mL and declined to 97.1 μg mL^–1 at 24 h. The area below the plasma concentration‐time curve was 5143 μg h^–1 mL^–1. The volumes of C₁ and C₂ were 86.9 and 63.9 mL kg^–1, respectively. Oxyglobin was not detected in urine. This study shows the detection and quantification in equine plasma of a HBOC following IV infusion and demonstrates the short half‐life of about 50% of infused bHb molecules.