A comparison between ethanol-induced chemical ablation and ivermectin plus prednizolone in the treatment of symptomatic esophageal spirocercosis in the dog: a prospective study on 14 natural cases

This study included a total of 14 dogs with spontaneous esophageal spirocercosis. Historical and clinical evidence of esophageal dysphagia, detection of parasitic ova in fecal samples and endoscopic documentation of esophageal nodules were the inclusion criteria. The animals were randomly assigned into two groups: group A (n = 6 ) dogs received two intranodular injections of absolute ethanol (96%) via a through-the-endoscope injector, at weekly intervals; group B (n = 8) dogs were put on ivermectin (600 microg/kg BW, subcutaneously, twice, 14 days apart) and oral prednisolone (0.5mg/kg BW, every 12h, for a total of 3 weeks, tapering the dose accordingly). Clinical and fecal examination as well as endoscopy, were performed on admission and at 20, 60 and 180 days from the beginning of the treatment. One group A dog responded poorly and died of pyothorax during the trial and another developed esophagitis due to accidental intraluminal ethanol infusion, only to experience an uneventful recovery. At different times during the 6-month follow-up period, there was a complete disappearance of the clinical signs in 4/6 group A dogs. However, full nodular regression was achieved only in one dog, and parasitic ova were still found in the feces of 4/6 dogs. At the same period of time in five group B dogs still available for evaluation, resolution of the clinical signs and complete nodular regression were seen in four and five animals, respectively, while negative fecal results were obtained in all dogs (8/8) of the same group 2 months from the beginning of the treatment. No significant difference was found between the groups, regarding the resolution of clinical signs, though group B dogs demonstrated a significantly higher rate of regression of esophageal nodules as well as negative fecal results, compared to group A dogs. The combination of ivermectin and prednizolone may be considered an effective treatment in the symptomatic and evidently asymptomatic esophageal spirocercosis of the dog.     

Diversity among Pseudomonas corrugata and Pseudomonas mediterranea isolated from tomato and pepper showing symptoms of pith necrosis in Greece

Bacterial isolates from tomato plants with symptoms revealing pith necrosis collected over a 20‐year period were screened and characterized using biochemical and pathogenicity tests, as well as molecular approaches. The examined isolates were categorized into two main Pseudomonas species: P. corrugata and P. mediterranea. The diversity of these isolates was characterized through a variety of biochemical, serological, pathogenicity, DNA fingerprinting and multi‐locus sequence analysis features. Of the total Pseudomonas isolates causing pith necrosis, the biochemical profile of the selected non‐fluorescent pseudomonads consisting of P. corrugata and P. mediterranea revealed differentiation in only three characters among 43 examined. Serological analysis managed to identify the P. corrugata isolates using the laboratory prepared antiserum anti‐PC14. Genomic analyses using rep‐PCR fingerprinting and multilocus sequence analysis (MLSA) revealed considerable inter‐ and intraspecies genetic diversity. However, artificial inoculations of several plant species revealed similar pathogenicity patterns for both P. corrugata and P. mediterranea isolates. These results provide the basis for a more comprehensive understanding of the biology, sources and shift in genetic diversity and evolution of both P. corrugata and P. mediterranea populations and could support the development of molecular identification tools and epidemiological studies in diseases caused by these species. Moreover, this is the first report of P. mediterranea in Greece on tomato as well as on pepper plants.     

Living at the edge: biogeographic patterns of habitat segregation conform to speciation by niche expansion in Anopheles gambiae

Background

Ongoing lineage splitting within the African malaria mosquito Anopheles gambiae is compatible with ecological speciation, the evolution of reproductive isolation by divergent natural selection acting on two populations exploiting alternative resources. Divergence between two molecular forms (M and S) identified by fixed differences in rDNA, and characterized by marked, although incomplete, reproductive isolation is occurring in West and Central Africa. To elucidate the role that ecology and geography play in speciation, we carried out a countrywide analysis of An. gambiae M and S habitat requirements, and that of their chromosomal variants, across Burkina Faso.

Results

Maps of relative abundance by geostatistical interpolators produced a distinct pattern of distribution: the M-form dominated in the northernmost arid zones, the S-form in the more humid southern regions. Maps of habitat suitability, quantified by Ecological Niche Factor Analysis based on 15 eco-geographical variables revealed less contrast among forms. M was peculiar as it occurred proportionally more in habitat of marginal quality. Measures of ecological niche breadth and overlap confirmed the mismatch between the fundamental and realized patterns of habitat occupation: forms segregated more than expected from the extent of divergence of their environmental envelope – a signature of niche expansion. Classification of chromosomal arm 2R karyotypes by multilocus genetic clustering identified two clusters loosely corresponding to molecular forms, with 'mismatches' representing admixed individuals due to shared ancestral polymorphism and/or residual hybridization. In multivariate ordination space, these karyotypes plotted in habitat of more marginal quality compared to non-admixed, 'typical', karyotypes. The distribution of 'typical' karyotypes along the main eco-climatic gradient followed a consistent pattern within and between forms, indicating an adaptive role of inversions at this geographical scale.

Conclusion

Ecological segregation between M and S is consistent with niche expansion into marginal habitats by chromosomal inversion variants during early lineage divergence; presumably, this process is promoted by inter-karyotype competition in the higher-quality core habitat. We propose that the appearance of favourable allelic combinations in other regions of suppressed recombination (e.g. pericentromeric portions defining speciation islands in An. gambiae) fosters development of reproductive isolation to protect linkage between separate chromosomal regions.     

Coupling ecosystem and individual‐based models to simulate the influence of environmental variability on potential growth and survival of larval sprat (Sprattus sprattus L.) in the North Sea

To investigate the impact of changing environmental conditions in the North Sea on the distribution and survival of early life stages of a marine fish species, we employed a suite of coupled model components: (i) an Eulerian coupled hydrodynamic/ecosystem (Nutrients, Phyto‐, Zooplankton, Detritus) model to provide both 3‐D fields of hydrographical properties, and spatially and temporally variable prey fields; (ii) a Lagrangian transport model to simulate temporal changes in cohort distribution; and (iii) an individual‐based model (IBM) to depict foraging, growth and survival of fish early life stages. In this application, the IBM was parameterized for sprat (Sprattus sprattus L.) and included non‐feeding (egg and yolk‐sac larval) stages as well as foraging and growth subroutines for feeding (post‐yolk sac) larvae. Sensitivity analyses indicated that the angle of visual acuity, assimilation efficiency and the maximum food consumption rate were the most critical intrinsic model parameters. As an example, we applied this model system for 1990 in the North Sea. Results included not only information concerning the interplay of temperature and prey availability on larval fish survival and growth but also information on mechanisms underlying larval fish aggregation within frontal zones. The good agreement between modelled and in situ estimates of sprat distribution and growth rates in the German Bight suggested that interconnecting these different models provided an expedient tool to scrutinize basic processes in fish population dynamics.     

Use of a soluble epoxide hydrolase inhibitor as an adjunctive analgesic in a horse with laminitis

HistoryA 4‐year old, 500 kg Thoroughbred female horse diagnosed with bilateral forelimb laminitis and cellulitis on the left forelimb became severely painful and refractory to non‐steroidal anti‐inflammatory therapy (flunixin meglumine on days 1, 2, 3 and 4; and phenylbutazone on days 5, 6 and 7) alone or in combination with gabapentin (days 6 and 7).Physical examinationPain scores assessed independently by three individuals with a visual analog scale (VAS; 0 = no pain and 10 = worst possible pain) were 8.5 on day 6, and it increased to 9.5 on day 7. Non‐invasive blood pressure monitoring revealed severe hypertension.ManagementAs euthanasia was being considered for humane reasons, a decision was made to add an experimental new drug, trans‐4‐{4‐[3‐(4‐Trifluoromethoxy‐phenyl)‐ureido]‐cyclohexyloxy}‐benzoic acid (t‐TUCB), which is a soluble epoxide hydrolase (sEH) inhibitor, to the treatment protocol. Dose and frequency of administration were selected based on the drug potency against equine sEH to produce plasma concentrations within the range of 30 nmol L^?1 and 2.5 μmol L^?1. Pain scores decreased sharply and remarkably following t‐TUCB administration and blood pressure progressively decreased to physiologic normal values. Plasma concentrations of t‐TUCB, measured daily, were within the expected range, whereas phenylbutazone and gabapentin plasma levels were below the suggested efficacious concentrations.Follow upNo adverse effects were detected on clinical and laboratory examinations during and after t‐TUCB administration. No new episodes of laminitis have been noted up to the time of writing (120 days following treatment).ConclusionsInhibition of sEH with t‐TUCB was associated with a significant improvement in pain scores in one horse with laminitis whose pain was refractory to the standard of care therapy. No adverse effects were noticed. Future studies evaluating the analgesic and protective effects of these compounds in painful inflammatory diseases in animals are warranted.     

Protactinium-231 and thorium-230 abundances and high scavenging rates in the western arctic ocean

The Canadian Basin of the Arctic Ocean, largely ice covered and isolated from deep contact with the more dynamic Eurasian Basin by the Lomonosov Ridge, has historically been considered an area of low productivity and particle flux and sluggish circulation. High-sensitivity mass-spectrometric measurements of the naturally occurring radionuclides protactinium-231 and thorium-230 in the deep Canada Basin and on the adjacent shelf indicate high particle fluxes and scavenging rates in this region. The thorium-232 data suggest that offshore advection of particulate material from the shelves contributes to scavenging of reactive materials in areas of permanent ice cover.     

The effect of the stage of the ovarian cycle (anoestrus or dioestrus) and of pregnancy on the incidence of gastro‐oesophageal reflux in dogs undergoing ovariohysterectomy

ObjectiveTo investigate the potential association of increased blood progesterone (P₄) concentrations and/or late pregnancy with the incidence of gastro-oesophageal reflux (GOR), in healthy bitches undergoing ovariohysterectomy under general anaesthesia during anoestrus or dioestrus or during the second half of pregnancy.Study designProspective observational study.AnimalsNinety-four healthy, female, dogs, aged 1–8 years presented for elective ovariohysterectomy.MethodsNon-pregnant animals were classified into group A (anoestrus) (n = 35) if blood P₄ concentration was sufficiently low or group D (dioestrus) (n = 26) if blood P₄ concentration was sufficiently high. All animals in the second half of pregnancy were classified into group P (n = 33). Acepromazine (0.05 mg kg⁻¹) was administered intramuscularly as preanaesthetic medication, and sodium thiopental (10 mg kg⁻¹, with additional doses if needed) was administered intravenously (IV) for induction of anaesthesia. After endotracheal intubation, halothane (1.1–1.3% end-tidal concentration) in oxygen was used for maintenance of anaesthesia. Lower oesophageal pH was monitored continuously throughout surgery using a pH-measuring probe. Reflux was considered to have occurred whenever pH values of >7.5 (alkaline reflux) or <4 (acid reflux) were recorded. On completion of surgery, carprofen (4 mg kg⁻¹) was administered IV. Further administration of analgesics post-operatively was dictated by visual analogue scale pain scoring.ResultAcid GOR was observed in five of 26 dogs in group D, six of 35 group A, and 12 of 33 group P (p = 0.152). The incidence of GOR in group P approached statistical significance and was higher than the incidence in the combined group A + D (one sided p = 0.044, two sided p = 0.077).ConclusionsIn dogs undergoing ovariohysterectomy, GOR during anaesthesia occurs with a high incidence in dogs in the second half of pregnancy compared to non-pregnant animals during anoestrus or dioestrus.Clinical relevanceMeasures could be taken in such cases to avoid the consequences of potential reflux.     

Thiopental and halothane dose-sparing effects of magnesium sulphate in dogs

OBJECTIVE :To evaluate the effect of pre- and intraoperatively administered magnesium sulphate (MgSO(4)) on the induction dose of thiopental and of halothane for maintenance of anaesthesia in dogs undergoing ovariohysterectomy (OHE). STUDY DESIGN: Prospective, double-blind, randomized, placebo-controlled study. ANIMALS: Forty-six healthy, ASA physical status 1 dogs, scheduled for elective OHE. METHODS: The dogs were randomly assigned to receive a bolus of 50 mg kg(-1) MgSO(4) intravenously (IV), just before induction of anaesthesia, followed by a constant rate infusion (CRI) of 12 mg kg(-1) hour(-1) MgSO(4) intraoperatively (group Mg, n = 27) or a placebo bolus and CRI of 0.9% sodium chloride (NaCl) (group C, n = 19), approximately 30 minutes after premedication with acepromazine (0.05 mg kg(-1), intramuscularly, IM) and carprofen (4 mg kg(-1), subcutaneously, SC). Anaesthesia was induced with thiopental administered to effect and maintained with halothane in oxygen. End-tidal halothane (ET(hal)) was adjusted to achieve adequate depth of anaesthesia. Blood samples were obtained pre- and postoperatively for measurement of total serum magnesium concentration. RESULTS: The mean dose of thiopental was statistically lower (p < 0.0005) and the mean standardized ET(hal) concentration and end-tidal carbon dioxide partial pressure (Pe'CO(2)) areas under the curve were statistically smaller (p < 0.0005 and 0.014 respectively) in group Mg. Postoperatively the mean total serum magnesium concentration was statistically higher than the preoperative value (p < 0.0005) in group Mg, but not in group C. Nausea, associated with the MgSO(4) bolus injection, was observed in six dogs in group Mg, two of which vomited prior to induction of anaesthesia. CONCLUSIONS AND CLINICAL RELEVANCE: Magnesium sulphate administration reduced the induction dose of thiopental and ET(hal) concentration for maintenance of anaesthesia in dogs undergoing OHE. Observed side effects were nausea and vomiting.     

Effect of pre-medication on gastroduodenoscopy in isoflurane-anesthetized cats

The pre‐medicant chosen may influence the ease with which gastroduodenoscopy (GD) is performed. The purpose of this study was to evaluate the relative ease of GD in cats under ketamine and isoflurane anesthesia after IM injection of hydromorphone (H, 0.1 mg kg^?1), hydromorphone plus glycopyrrolate (HG, 0.1 mg kg^?1 (H), 0.01 mg kg^?1 (G)), medetomidine (M, 0.03 mg kg^?1), or butorphanol (B, 0.4 mg kg^?1). Eight cats were assigned randomly to receive each treatment in a cross‐over design with at least 7 days between treatments. Twenty minutes after pre‐medication, medetomidine produced greater (p = 0.001) sedation than the other treatments when assessed, using a subjective ordinal scale. The cats were injected with ketamine (10 mg kg^?1 IM), orotracheally intubated, connected to a pediatric circle breathing system, and allowed to spontaneously breathe isoflurane in oxygen. Once end‐tidal isoflurane concentration was stable at 1.4% for 15 minutes, endoscopy was started. A single endoscopist (REG), who was unaware of the treatment used, performed all endoscopies. The endoscopist scored the difficulty of endoscopy subjectively (0–3). The significance of differences between treatments was evaluated using Friedman's test. Time for entering the stomach was 9.4 (4.7–15.9) (median (minimum–maximum)), 6.6 (5.2–11.7), 8.4 (6.3–16.5), and 7.7 (5.1–14.7) seconds and for entering the duodenum from the stomach was 20.5 (13.8–40.9), 18.2 (10.3–39.8), 20.2 (16.2–119.5), and 22.2 (11.8–83.8) seconds for H, HG, M, and B treatments, respectively. There were no significant differences in the time for, or difficulty of, endoscopy. We conclude that any of these drugs can be used satisfactorily at the doses and combinations tested to pre‐medicate cats prior to general anesthesia for GD.