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1.
Oecologia ; 200(1-2): 159-168, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36053351

ABSTRACT

The size of organisms may result from various, sometimes antagonistic forces operating on distinct traits, within an evolutionary framework that may also be constraining. Morphological allometry, referring to the way trait size scales with body size, has been shown to reflect ecological adaptation to the mean size of the resource exploited. We examined the allometric relationships between rostrum and body size among four insect (Curculio spp.) specialists of oak acorns. In all four species, weevil females drill a hole with their rostrum prior depositing one or a few eggs inside the seed. The four weevil species, that coexist on the same individual trees, displayed partitioned egg-laying periods in the year, thereby encountering acorns of different size and maturation stage. We found marked differences in the allometric slope among females: species laying eggs late in the season had a steeper slope, leading to increasingly longer rostrum relative to body length, along with the mean size of the growing acorns. Females of the smallest species had the longest oviposition period and also had the steepest slope, which provided them with the most variable rostrum length, thereby matching the variable size of the resource through time. Our work highlights the need to consider not only the average size but also the degree of variability in resource size to understand the adaptive value of allometric relationships.


Subject(s)
Quercus , Weevils , Animals , Biological Evolution , Body Size , Female , Insecta , Weevils/anatomy & histology
2.
Equine Vet J ; 52(2): 200-204, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31390081

ABSTRACT

BACKGROUND: The clinical findings and outcome associated with chronic severe equine pyloric lesions have not been well described previously. OBJECTIVES: To describe the history, clinical signs, endoscopic and ultrasound results, laboratory data, treatment, pathological findings and survival of horses with chronic severe pyloric lesions. STUDY DESIGN: Retrospective case series. METHODS: Medical records from horses treated at clinics in Czech Republic and Germany in which chronic severe pyloric lesions were confirmed endoscopically and/or on post-mortem examination were reviewed. RESULTS: Forty-seven horses were identified, median age 3 years (range 0.8-16 years). There were 3 geldings, 23 mares and 19 stallions and the majority were Warmbloods (60%). The most common presenting signs were poor body condition (40; 87%), slow eating (39; 83%), recurrent colic (35; 74%) and selective appetite (30; 64%). The most consistent laboratory abnormality was hypoalbuminaemia (10; 36%). Slow gastric emptying was confirmed in 29 individuals during gastroscopy and/or ultrasonography. Endoscopy revealed distal oesophagitis in 9 of 47 horses, and severe equine squamous gastric disease in all cases. Pyloric lesions were depressed, flat or raised fibrinosuppurative pyloric ulcers and were seen in 45 (2 pylori were not seen endoscopically). Thirty-two cases were treated, with 28 responding well initially. All treated cases received anti-ulcer medication and four underwent gastrojejunostomy. Clinical signs recurred after medical treatment in at least 11 cases. Only 18 of 44 cases (41%) survived long term (3 were lost to follow-up). Horses diagnosed at 3 years of age or younger were significantly less likely to survive more than 6 months than older horses (27.8% vs. 72.2%, P<0.001). MAIN LIMITATIONS: The study is retrospective, some records were incomplete and case identification was subjective. CONCLUSIONS: Chronic severe pyloric lesions can be associated with delayed gastric emptying identified with ultrasonography and/or endoscopy. The prognosis is poor in young horses.


Subject(s)
Horse Diseases , Stomach Ulcer/veterinary , Animals , Female , Germany , Horses , Male , Retrospective Studies
3.
Vet J ; 246: 66-70, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30902191

ABSTRACT

After strangles outbreaks, Streptococcus equi ssp. equi (S. equi) can persist in clinically normal silent carriers for months to years. Two naturally occurring outbreaks of strangles with 53 and 100% morbidity, respectively, were followed longitudinally to assess occurrence of carrier state and optimal detection methods Outbreak A involved 98 yearling warmbloods, and outbreak B 38 mature Icelandic horses. Fully recovered horses were sampled at least 6 months after index cases using nasal swabs (one sampling occasion only) nasopharyngeal lavage and guttural pouch visualisation and lavages for culture and qPCR to S. equi. Any horse with at least a single sample positive was deemed a carrier. Descriptive statistics and sensitivity and negative predictive values were calculated. Comparisons were made with McNemars and Fishers exact tests. Carrier rates in outbreak A were 3% based on culture and 15% based on qPCR and for outbreak B 13% based on culture and 37% based on qPCR. All culture positives were also qPCR positive. One carrier culture negative sampled after an additional 8 months was culture positive to S. equi, indicating that qPCR positives should be suspected to carry live bacteria. Findings indicate that reliance on guttural pouch sampling and appearance does not capture all silent carriers. All culture positives were identified by qPCR and even horses positive by qPCR but culture negative should be suspected carriers of live bacteria.


Subject(s)
Carrier State/veterinary , Ear, Middle/microbiology , Horse Diseases/diagnosis , Real-Time Polymerase Chain Reaction/veterinary , Streptococcal Infections/veterinary , Streptococcus equi/isolation & purification , Animals , Carrier State/diagnosis , Carrier State/epidemiology , Disease Outbreaks/veterinary , Female , Horse Diseases/microbiology , Horses , Longitudinal Studies , Male , Nasal Lavage/veterinary , Streptococcal Infections/diagnosis , Streptococcal Infections/epidemiology , Streptococcus equi/growth & development
4.
J Vet Intern Med ; 32(1): 459-464, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29377359

ABSTRACT

BACKGROUND: Streptococcus equi ssp. equi causes characteristic clinical signs that are most severe in young horses, including fever, purulent nasal discharge, and lymph node abscessation in the head region. HYPOTHESIS/OBJECTIVES: Clinical, serologic, and microbiologic factors related to unexpectedly mild disease severity in a natural outbreak of strangles in immunologically naïve weanlings were investigated. ANIMALS: One-hundred and twelve warmblood weanlings. METHODS: Prospective longitudinal observational study of a natural outbreak of strangles. The entire cohort was examined at the peak of the outbreak by deep nasal swabs for culture and quantitative PCR (qPCR) for the presence of S. equi and clinically and serologically in a sequential manner by an optimized ELISA from the index case throughout the outbreak until resolution. Descriptive statistics were calculated and comparisons made using a nondirectional Wilcoxon signed-rank test. RESULTS: Outbreak morbidity was 53%, with 9 of 14 horses culture positive and 26 of 53 horses qPCR positive for S. equi lacking clinical signs characteristic of strangles. By resolution, 91 of 112 had seroconverted to Antigen A by ELISA but seroconversion to antigen C (part of the SeM protein) was minimal. Sequencing of the isolates detected no alterations in the SeM protein, but identified a 61 bp deletion in the gene SEQ_0402. CONCLUSIONS AND CLINICAL IMPORTANCE: Absence of clinical signs alone in naïve horses may be an insufficient criterion to release horses from strangles quarantine measures. Restricted seroconversion to antigen C may have been associated with decreased clinical severity. The role of a minor gene deletion in SEQ_0402 in the virulence of S. equi warrants further investigation.


Subject(s)
Horse Diseases/microbiology , Seroconversion , Streptococcal Infections/veterinary , Streptococcus equi/isolation & purification , Animals , Disease Outbreaks/veterinary , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Horse Diseases/immunology , Horses , Male , Nasal Cavity/microbiology , Polymerase Chain Reaction/veterinary , Prospective Studies , Streptococcal Infections/immunology , Streptococcal Infections/microbiology , Streptococcus equi/genetics , Streptococcus equi/immunology
5.
Equine Vet J ; 50(4): 525-531, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29239016

ABSTRACT

BACKGROUND: Standard treatment of foals with severe abscessing lung infection caused by Rhodococcus equi using rifampicin and a macrolide antibiotic can be compromised by extensive inhibition and/or induction of drug metabolising enzymes (e.g. CYP3A4) and transport proteins (e.g. P-glycoprotein), as has been shown for rifampicin and clarithromycin. The combination of rifampicin with the new, poorly metabolised gamithromycin, a long-acting analogue of azithromycin and tulathromycin with lower pharmacokinetic interaction potential, might be a suitable alternative. OBJECTIVES: To evaluate the pharmacokinetic interactions and pulmonary distribution of rifampicin and gamithromycin in healthy foals, and to investigate the cellular uptake of gamithromycin in vitro. STUDY DESIGN: Controlled, four-period, consecutive, single-dose and multiple-dose study. METHODS: Pharmacokinetics and lung distribution of rifampicin (10 mg/kg) and gamithromycin (6 mg/kg) were measured in nine healthy foals using LC-MS/MS. Enzyme induction was confirmed using the 4ß-OH-cholesterol/cholesterol ratio. Affinity of gamithromycin to drug transport proteins was evaluated in vitro using equine hepatocytes and MDCKII-cells stably transfected with human OATP1B1, OATP1B3 and OATP2B1. RESULTS: Rifampicin significantly (P<0.05) increased the plasma exposure of gamithromycin (16.2 ± 4.77 vs. 8.57 ± 3.10 µg × h/mL) by decreasing the total body clearance. Otherwise, gamithromycin significantly lowered plasma exposure of single- and multiple-dose rifampicin (83.8 ± 35.3 and 112 ± 43.1 vs. 164 ± 96.7 µg × h/mL) without a change in metabolic ratio and half-life. Gamithromycin was identified as an inhibitor of human OATP1B1, OATP1B3 and OATP2B1 and as a substrate of OATP2B1. In addition, it was extracted by equine hepatocytes via a mechanism which could be inhibited by rifampicin. MAIN LIMITATIONS: Influence of gamithromycin on pulmonary distribution of rifampicin was not evaluated. CONCLUSION: The plasma exposure of gamithromycin is significantly increased by co-administration of rifampicin which is most likely caused by inhibition of hepatic elimination.


Subject(s)
Anti-Bacterial Agents/pharmacokinetics , Horses/blood , Macrolides/pharmacokinetics , Rifampin/pharmacokinetics , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/blood , Area Under Curve , Biomarkers , Dogs , Drug Administration Schedule , Drug Interactions , Female , Half-Life , Macrolides/administration & dosage , Macrolides/blood , Madin Darby Canine Kidney Cells , Male , Rifampin/administration & dosage , Rifampin/blood
6.
J Vet Intern Med ; 31(3): 901-906, 2017 05.
Article in English | MEDLINE | ID: mdl-28421633

ABSTRACT

BACKGROUND: There is conflicting data regarding the efficacy of tulathromycin for the treatment of foals with bronchopneumonia. HYPOTHESES: Tulathromycin is effective for the treatment of bronchopneumonia in foals and noninferior to the combination of azithromycin and rifampin. ANIMALS: A total of 240 foals on a farm endemic for infections caused by Rhodococcus equi. METHODS: In a controlled, randomized, and double-blinded clinical trial, foals with ultrasonographic pulmonary lesions (abscess score 10-15 cm) were allocated to 3 groups: 1-tulathromycin IM q 7 days (n = 80); 2-azithromycin-rifampin, orally q24h (n = 80); or 3-untreated controls (n = 80). Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals that worsened were considered treatment failures and removed from the study. RESULTS: The proportion of foals that recovered was significantly higher for foals treated with tulathromycin (70 of 79) or azithromycin-rifampin (76 of 80) compared to that of control foals (22 of 80). The difference in the percentage of efficacy of azithromycin-rifampin versus tulathromycin was 6.4% (90% CI = -0.72-13.5%). Given that the confidence interval crossed the predetermined noninferiority limit of 10%, the null hypothesis that the response rate in the azithromycin-rifampin group is superior to that of the tulathromycin group could not be rejected. Resolution of ultrasonographic lesions occurred faster in foals treated with azithromycin-rifampin than in foals treated with tulathromycin. CONCLUSION AND CLINICAL IMPORTANCE: Tulathromycin was effective for the treatment of bronchopneumonia in foals at this farm but not as effective as the combination of azithromycin-rifampin.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bronchopneumonia/veterinary , Disaccharides/therapeutic use , Heterocyclic Compounds/therapeutic use , Horse Diseases/drug therapy , Actinomycetales Infections/drug therapy , Actinomycetales Infections/veterinary , Animals , Azithromycin/administration & dosage , Azithromycin/therapeutic use , Bronchopneumonia/drug therapy , Bronchopneumonia/microbiology , Double-Blind Method , Drug Therapy, Combination/veterinary , Female , Horses , Male , Rhodococcus equi/drug effects , Rifampin/administration & dosage , Rifampin/therapeutic use , Treatment Outcome
7.
J Vet Pharmacol Ther ; 40(4): 406-410, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28317153

ABSTRACT

The long-acting azalide antibiotic gamithromycin is marketed for intramuscular treatment of bovine and swine infections. Off-label use in foals leads to severe local lesions likely caused by hyperosmolality of the injected solution. We provide evidence from a pharmacokinetic study in 10 warm-blooded healthy foals for intravenous bolus injection of gamithromycin diluted in distilled water to be a safe and well tolerated alternative. By intravenous dosing, markedly higher plasma exposure and better penetration into bronchoalveolar lavage cells but lower distribution into epithelial lining fluid are achieved as after intramuscular or subcutaneous administration. Intravenously injected gamithromycin was tolerated without any adverse drug reactions. The protocols for treatment of equine pulmonary infections caused by Rhodococcus equi should be revised accordingly.


Subject(s)
Actinomycetales Infections/veterinary , Horse Diseases/drug therapy , Horses/metabolism , Infusions, Intravenous/veterinary , Macrolides/pharmacokinetics , Rhodococcus equi , Actinomycetales Infections/drug therapy , Animals , Cattle , Lung/metabolism , Macrolides/administration & dosage
8.
Equine Vet J ; 49(5): 618-623, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28063154

ABSTRACT

BACKGROUND: The treatment of equine lung infections by Rhodococcus equi with rifampicin is empirically based because pharmacokinetic/pharmacodynamic (PK/PD) indices and pivotal clinical outcome data are not available. OBJECTIVES: To evaluate the pharmacokinetics and pulmonary distribution of rifampicin into epithelial lining fluid (ELF) and bronchoalveolar lavage cells (BALC) to predict antimicrobial activity in the lung using PK/PD indices. STUDY DESIGN: Controlled, randomised, two-period, crossover, repeated-dose study with an initial arm to measure disposition after i.v. administration of rifampicin. METHODS: Pharmacokinetics and lung distribution were evaluated in six healthy foals treated with 10 mg/kg bwt rifampicin i.v. (initial arm) and with repeated oral doses of rifampicin at 10 mg/kg bwt and 20 mg/kg bwt once per day for 10 days (crossover arms). ELF and BALC were sampled by bronchoalveolar lavage 24 h after the last oral dosing. Rifampicin and 25-O-desacetyl rifampicin were quantified using liquid chromatography tandem-mass spectrometry. Enzyme induction by rifampicin was confirmed by evaluation of plasma 4ß-OH-cholesterol:cholesterol ratios. RESULTS: The distribution volume of rifampicin administered i.v. was ~0.85 L/kg. Terminal elimination half-life was ~11 h. Orally given rifampicin was slowly absorbed (Tmax , range: 2.5-8.0 h) and eliminated with apparent half-lives of ~6-8 h. Trough concentrations in ELF and BALC were 1.01 ± 0.20 µg/mL and 1.25 ± 0.29 µg/mL, respectively, after 10 mg/kg bwt rifampicin and 2.71 ± 1.25 µg/mL and 3.09 ± 1.63 µg/mL, respectively, after 20 mg/kg bwt rifampicin. The average ratios of area under the plasma concentration time curve during an administration interval of 24 h (AUC0-24 h ) to minimum inhibitory concentration (MIC) were 145 and 322 h, respectively, for less susceptible strains of R. equi (MIC90 : 0.5 µg/mL). MAIN LIMITATIONS: The clearance and bioavailability of rifampicin after repeated oral dosing were not evaluated. CONCLUSIONS: Treatment with rifampicin at 10 mg/kg bwt administered once per day is suitable to generate drug concentrations above the MIC90 in the ELF and BALC of foals. Future clinical studies with rifampicin in combination with macrolide antibiotics with low drug interaction potential are required to translate the PK/PD indices into protocols for the treatment of R. equi lung infections.


Subject(s)
Anti-Bacterial Agents/pharmacokinetics , Lung/metabolism , Rifampin/pharmacokinetics , Administration, Oral , Animals , Area Under Curve , Half-Life , Horses , Random Allocation
9.
Equine Vet J ; 49(2): 149-154, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27037614

ABSTRACT

REASONS FOR PERFORMING STUDY: Failure of transfer of passive immunity (FTPI) in foals is associated with a risk of infection and death. The current diagnostic gold standard is quantification of immunoglobulins using radial immunodiffusion (IgG-RID). Routine diagnosis is often performed using semi-quantitative tests. Concentrations of serum electrophoretic gamma globulins (EGG) and total globulins may be useful to assess FTPI, but few studies have investigated their use. OBJECTIVES: To assess agreement between IgG-RID and EGG and evaluate the accuracy of total globulin concentration to diagnose FTPI based on both IgG-RID and EGG. STUDY DESIGN: Prospective study. METHODS: A total of 360 serum samples were harvested at 6-24 h post natum from 60 German Warmblood foals. Concentrations of EGG, IgG-RID and total globulin (calculated from total proteins and albumin) were measured. Agreement between EGG and IgG-RID was assessed using Bland-Altman plots and Passing-Bablok regression. The accuracy of total globulin concentration was assessed using rank correlation and ROC curve analysis. RESULTS: Good agreement was found with slightly lower EGG than IgG-RID concentrations (Bland-Altman systemic bias -1.9 g/l) which was more pronounced at higher concentrations (regression equation: IgG-RID = -0.78 + 1.28 × EGG). Correlations between total globulin concentration and EGG and total globulin concentration and IgG-RID were 0.93 and 0.79, respectively. The area under the curve was 0.982 and 0.952 for EGG <4 and <8 g/l and 0.953 and 0.899 for IgG-RID <4 and <8 g/l. Sensitivities and specificities of total globulin concentration in the diagnosis of FTPI were comparable to those of commonly used screening tests, but cut-offs could be selected to achieve sensitivities of >95% with 71.2% (IgG-RID) and 90.5% (EGG) specificity for <4 g/l and >90% with 66.0% (IgG-RID) and 87.9% (EGG) specificity for <8 g/l. CONCLUSIONS: There is good agreement between EGG and IgG-RID, with slightly more conservative estimates of immunoglobulins obtained using EGG. Total globulins may be a useful and economic quantitative screening test with cut-offs achieving high sensitivities, but analyser-specific cut-offs may be necessary.


Subject(s)
Electrophoresis/veterinary , Horses/blood , Immunodiffusion/veterinary , Immunoglobulin G/blood , Animals , Animals, Newborn , Electrophoresis/methods , Female , Immunodiffusion/methods , Male , Prospective Studies
10.
J Vet Intern Med ; 29(1): 333-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25619521

ABSTRACT

BACKGROUND: Gamithromycin is active in vitro against the bacterial agents most commonly associated with bronchopneumonia in older foals. However, the clinical efficacy and safety of this drug have not been investigated. HYPOTHESIS: Gamithromycin is effective for the treatment of bronchopneumonia in foals. ANIMALS: One hundred and twenty-one foals on a farm endemic for infections caused by Rhodococcus equi. METHODS: In a controlled, randomized, and double blinded clinical trial, foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-20 cm) were randomly allocated in 3 treatment groups: (1) gamithromycin IM q7 days (n = 40); (2) azithromycin with rifampin, PO q24h (n = 40); or (3) no antimicrobial treatment (controls; n = 41). Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals that worsened were removed from the study. RESULTS: The proportion of foals that recovered without the need to be removed from the study was significantly higher for foals treated with gamithromycin (38 of 40) or azithromycin with rifampin (39 of 40) than for controls (32 of 41). Treatment with gamithromycin or with azithromycin-rifampin resulted in a significantly faster decrease in the clinical score and abscess score compared to the controls. Adverse reactions characterized by colic (n = 18) and hind limb lameness (n = 14) were observed only in foals treated with gamithromycin. CONCLUSION AND CLINICAL IMPORTANCE: Gamithromycin was noninferior to azithromycin with rifampin for the treatment of bronchopneumonia in the study population but had a higher frequency of adverse reactions.


Subject(s)
Actinomycetales Infections/veterinary , Anti-Bacterial Agents/therapeutic use , Bronchopneumonia/veterinary , Horse Diseases/microbiology , Macrolides/therapeutic use , Abscess/microbiology , Abscess/veterinary , Animals , Azithromycin/administration & dosage , Azithromycin/therapeutic use , Bronchopneumonia/drug therapy , Double-Blind Method , Drug Therapy, Combination , Female , Horse Diseases/drug therapy , Horses , Male , Rhodococcus equi , Rifampin/administration & dosage , Rifampin/therapeutic use
11.
Vet Rec ; 173(16): 397, 2013 Oct 26.
Article in English | MEDLINE | ID: mdl-24106244

ABSTRACT

The objectives of the present study were to determine the relative efficacy of tulathromycin, azithromycin, or azithromycin with rifampin for the treatment of pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi. Foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-15 cm; n=120) were randomly allocated in four equal treatment groups: (1) tulathromycin intramuscularly; (2) azithromycin monotherapy, orally; (3) azithromycin with rifampin, orally; (4) saline intramuscularly as a placebo. Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals that worsened were removed from the study. The proportion of foals that recovered without the need for a change in therapy was significantly higher for foals treated with azithromycin (29 of 30) or azithromycin with rifampin (28 of 30) than for foals treated with a placebo (20 of 30). Additionally, azithromycin or azithromycin with rifampin resulted in a significantly faster decrease in the number of abscesses and abscess score compared with a placebo. The proportion of foals treated with tulathromycin that recovered (27 of 30) was not significantly different from that of foals treated with a placebo. Azithromycin alone or in combination with rifampin was beneficial in the study population.


Subject(s)
Actinomycetales Infections/veterinary , Anti-Bacterial Agents/therapeutic use , Azithromycin/therapeutic use , Disaccharides/therapeutic use , Endemic Diseases/veterinary , Heterocyclic Compounds/therapeutic use , Horse Diseases/drug therapy , Lung Abscess/veterinary , Pneumonia, Bacterial/veterinary , Rifampin/therapeutic use , Actinomycetales Infections/drug therapy , Actinomycetales Infections/epidemiology , Animals , Double-Blind Method , Drug Therapy, Combination/veterinary , Germany/epidemiology , Horse Diseases/epidemiology , Horses , Lung Abscess/drug therapy , Pneumonia, Bacterial/drug therapy , Pneumonia, Bacterial/microbiology , Rhodococcus equi , Severity of Illness Index , Treatment Outcome
13.
J Vet Intern Med ; 27(1): 171-6, 2013.
Article in English | MEDLINE | ID: mdl-23278131

ABSTRACT

BACKGROUND: Mass antimicrobial treatment of foals with small subclinical ultrasonographic pulmonary lesions is empirical practice on many farms with endemic disease caused by Rhodococcus equi. HYPOTHESIS: Mass antimicrobial treatment of foals with subclinical ultrasonographic pulmonary lesions is unnecessary. ANIMALS: One hundred and eight foals on a farm endemic for infections caused by R. equi. METHODS: Controlled, randomized, and double-blinded prospective study. Foals with ultrasonographic evidence of pulmonary abscesses 5.0-10 cm in diameter (n = 108) were randomly allocated in 5 treatment groups: (1) tulathromycin IM; (2) doxycycline monotherapy PO; (3) doxycycline with rifampin PO; (4) azithromycin with rifampin PO, and (5) saline IM as a placebo. Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals with evidence of disease progression were removed from the study and treated with azithromycin-rifampin. RESULTS: Overall, 22/25 (88%) foals in the placebo group recovered without the need for treatment. The proportion of foals that had evidence of disease progression did not differ significantly between the treatment groups (P > .05). Although the median duration of treatment was significantly (P < .05) shorter in foals treated with azithromycin-rifampin (46 days) compared with foals treated with the placebo (73 days), the time frame of ultrasonographic lesion resolution did not differ significantly between the treatment groups. CONCLUSIONS AND CLINICAL IMPORTANCE: The majority of foals with subclinical pulmonary abscesses <10 cm in diameter recover without antimicrobial treatment and treatment of affected foals does not provide a clear benefit over administration of a placebo.


Subject(s)
Actinomycetales Infections/veterinary , Anti-Bacterial Agents/therapeutic use , Horse Diseases/drug therapy , Lung Abscess/veterinary , Rhodococcus equi , Actinomycetales Infections/drug therapy , Animals , Double-Blind Method , Female , Horse Diseases/microbiology , Horses , Lung Abscess/drug therapy , Male , Treatment Outcome
14.
J Comp Pathol ; 143(2-3): 203-8, 2010.
Article in English | MEDLINE | ID: mdl-20153871

ABSTRACT

Borna disease (BD) was diagnosed in a 2-year-old male alpaca with a history of chronic suppressed sexual desire and acute stretching convulsions. Microscopical examination of the central nervous system revealed non-purulent meningoencephalitis with mononuclear perivascular cuffing. The diagnosis was confirmed by immunohistochemistry, in-situ hybridization, polymerase chain reaction (PCR) and sequencing of PCR products and alignment with known Borna disease virus sequences. Serological screening of the herd was performed. This is the first detailed report of naturally occurring BD in alpacas.


Subject(s)
Borna Disease/diagnosis , Borna disease virus/isolation & purification , Camelids, New World/virology , Animals , Borna Disease/pathology , Borna disease virus/genetics , Borna disease virus/immunology , Brain/pathology , Brain/virology , Fatal Outcome , Germany , Male , Meningoencephalitis/pathology , RNA, Viral/genetics , Sequence Analysis, RNA
15.
Proc Biol Sci ; 275(1630): 77-82, 2008 Jan 07.
Article in English | MEDLINE | ID: mdl-17956845

ABSTRACT

Sexual selection theory traditionally considers choosiness for mates to be negatively related to intra-sexual competition. Males were classically considered to be the competing, but not the choosy, sex. However, evidence of male choosiness is now accumulating. Male choosiness is expected to increase with an individual's competitive ability, and to decrease as intra-sexual competition increases. However, such predictions have never been tested in field conditions. Here, we explore male mate choice in a spider by studying size-assortative pairing in two natural sites that strongly differ in the level of male-male competition. Unexpectedly, our results demonstrate that mate choice shifts from opportunism to high selectivity as competition between males increases. Males experiencing weak competition did not exhibit size-related mating preferences. By contrast, when competition was intense we found strong size-assortative pairing due to male choice: while larger, more competitive males preferentially paired with larger, more fecund females, smaller males chose smaller females. Thus, we show that mating preferences of males vary with their competitive ability. The distinct preferences exhibited by males of different sizes seem to be an adaptive response to the lower reproductive opportunities arising from increased competition between males.


Subject(s)
Mating Preference, Animal/physiology , Spiders/physiology , Animals , Body Size/physiology , Competitive Behavior/physiology , Female , Fertility/physiology , France , Male , Sex Ratio , Spiders/anatomy & histology
16.
Res Vet Sci ; 83(3): 311-7, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17360011

ABSTRACT

Pulsotypes of VapA positive Rhodococcus equi isolated from foals and soil on a farm in Germany were characterized on the basis of nasal and tracheal samples simultaneously collected in 2003 from 217 foals with sonographic evidence of pneumonia or pulmonary abscesses. Of the 217 double samples, R. equi was isolated in 118 (54%) of the tracheal samples and in 52 of the nasal swab samples (24%) (P<0.001). Furthermore, 37 and 55 isolates were also randomly selected from nasal swabs and the tracheal samples, respectively, and further processed to determine the presence of VapA by colony blot enzyme-linked immunosorbent assay. This method showed that 26 (68%) of the nasal swabs and 40 (73%) of the tracheal samples were VapA-positive. R. equi was isolated from 56 (87%) of the 64 soil samples taken from the paddocks and stables in March and from 17 (68%) of the 25 samples taken in July of 2003. Three (21%) of these randomly selected 14 isolates from March and 13 (81%) of the 16 from July were VapA-positive. The VapA positive isolates from foals and soil were genotyped by plasmid profiling, restriction fragment length polymorphism analysis and pulsed-field gel electrophoresis. Of the 83 isolates, 80 contained an 85-kb type I plasmid and three contained an 87-kb type I plasmid. Pulsed-field gel electrophoresis yielded four distinct VspI profiles dividing 83 isolates into three major (A1, 51; D, 14; and 11 isolates) and three minor (C, 4; A3, 2; and A2, 1 isolates) groups. These results suggest that the majority of foals were exposed to and infected with three pulsotypes of VapA positive R. equi containing an 85-kb type I plasmid.


Subject(s)
Actinomycetales Infections/veterinary , Horse Diseases/microbiology , Lung Abscess/veterinary , Pneumonia/veterinary , Rhodococcus equi/genetics , Soil Microbiology , Actinomycetales Infections/microbiology , Animals , Breeding , Genotype , Germany , Horses , Lung Abscess/microbiology , Pneumonia/microbiology , Virulence Factors/genetics
17.
Dtsch Tierarztl Wochenschr ; 114(12): 470-2, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18181362

ABSTRACT

A ventral meningomyelocele was found in a five week old, male German warmblood foal which exhibited central nervous symptoms. This rare malformation in horses may be caused by absent or defective fusion of vertebral bodies leading to herniation of the spinal cord and meninges with subsequent degenerative alterations of the spinal cord.


Subject(s)
Hernia/veterinary , Horse Diseases/diagnosis , Meningomyelocele/veterinary , Animals , Fatal Outcome , Hernia/diagnosis , Hernia/pathology , Horse Diseases/pathology , Horses , Immunohistochemistry/veterinary , Male , Meningomyelocele/diagnosis , Meningomyelocele/pathology
18.
J Vet Intern Med ; 20(4): 968-73, 2006.
Article in English | MEDLINE | ID: mdl-16955824

ABSTRACT

The aim of the study reported here was to compare complications of lung biopsy in horses and the quality of the lung specimens after biopsy using the manual Tru-Cut biopsy needle (TC) and an automated biopsy needle (ABN). For experiment 1, lung biopsy was performed in 50 horses with one instrument on one side of the thorax, and then with the other instrument on the other side. Postmortem examination was performed in 20 of the 50 horses. Coughing was detected in 10 of 50 horses and epistaxis was observed in 6 of the 50 horses. Endoscopy revealed bleeding into the airways in 16 of 49 horses and in 5 of 49 horses after biopsy with the TC or the ABN, respectively. Use of the ABN induced a significantly smaller amount of bleeding. Pneumothorax was detected by radiography in 1 of 50 horses. Hematoma diameter determined in 7 of 20 horses at postmortem examination, was significantly larger after biopsy with the TC than with the ABN. The quality of the lung specimen was good. In experiment 2, complications after repeated and multiple lung biopsies in 6 horses were evaluated. Moderate epistaxis was observed on 13 of 104 occasions. Bleeding into the airways was detected at endoscopy on 41 of 104 occasions, and pneumothorax was detected during 4 of 104 occasions. Complications such as hematoma at the biopsy site and bleeding into the airways were greater after biopsy with the TC than after use of the ABN. Lung biopsy specimens obtained with the ABN were fairly safe for the animal.


Subject(s)
Horse Diseases/diagnosis , Lung Diseases, Interstitial/veterinary , Lung/pathology , Animals , Biopsy, Needle/instrumentation , Biopsy, Needle/veterinary , Female , Horses , Lung Diseases, Interstitial/diagnosis , Male
19.
J Comp Pathol ; 131(2-3): 186-98, 2004.
Article in English | MEDLINE | ID: mdl-15276858

ABSTRACT

Interstitial lung disease with chronic fibrosis is a frequent cause of reduced performance in horses. The aim of this study was to establish a model of acute alveolar damage and interstitial lung disease in horses that could be used to monitor the histopathological lesions and changes in expression levels of genes relevant to pulmonary fibrosis. Six adult horses were given a single intravenous injection (6 mg per kg body weight) of perilla mint ketone (PMK). Transthoracic lung biopsy samples (1 x 0.2 x 0.2 cm) were collected before and after (days 1, 4, 8, 11, 15, 18, 22, 25 and 29) the administration of PMK. Light and electron microscopy revealed severe acute alveolar damage (days 1 to 4), proliferation of type II pneumocytes (days 4 to 11) and finally complete healing at about day 18. However, unexpectedly severe clinical signs necessitated euthanasia in two horses on days 9 and 11. The expression levels of the collagen genes COL1AI and COL3AI as well as transforming growth factor (TGF)-beta were examined in the biopsy samples by reverse transcription-real time quantitative polymerase chain reaction. COL1AI and COL3AI gene expressions were upregulated (3- and 17-fold, respectively) between days 1 and 29 in all six horses, whereas TGF-beta was upregulated in two horses (2- and 4-fold, respectively), between days 4 and 18. Although the gene expression analyses indicated a strong activation of the pro-fibrotic pathway, no interstitial fibrosis was seen in any horse. A complete necropsy performed on day 60 revealed complete recovery of the lungs of the four surviving horses, with no evidence of fibrosis. Unidentified compensatory mechanisms may have prevented pulmonary fibrosis, despite strong upregulation of pro-fibrotic genes.


Subject(s)
Lung Diseases, Interstitial/physiopathology , Monoterpenes/adverse effects , Procollagen/biosynthesis , Pulmonary Fibrosis/physiopathology , Animals , Disease Models, Animal , Female , Gene Expression , Horses , Immunohistochemistry , Lung Diseases, Interstitial/chemically induced , Lung Diseases, Interstitial/genetics , Male , Microscopy, Electron, Transmission , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/genetics , Reverse Transcriptase Polymerase Chain Reaction , Transforming Growth Factor beta/biosynthesis
20.
Dtsch Tierarztl Wochenschr ; 107(12): 472-6, 2000 Dec.
Article in German | MEDLINE | ID: mdl-11155515

ABSTRACT

In 10 horses, which were referred to the clinic with the suspicion of disorders of the gastrointestinal tract, gastroscopy revealed a gastric tumour. In ten cases the diagnosis of a squamous cell carcinoma was made on the basis of histology of biopsies or autopsy. The tumour always derived from the non-glandulary mucosa. The horses showed various clinical symptoms. All patients had a hypoalbuminemia and a hyperglobulinemia in the serum electrophoresis. This suggests that a gastric tumour can be suspected intra-vitam even without gastroscopy of the patient.


Subject(s)
Horse Diseases/diagnosis , Stomach Neoplasms/veterinary , Animals , Autopsy , Female , Gastric Mucosa/pathology , Horse Diseases/pathology , Horses , Male , Stomach Neoplasms/diagnosis , Stomach Neoplasms/pathology
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