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1.
J Vet Intern Med ; 37(1): 338-348, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36478588

RESUMO

BACKGROUND: Racehorses commonly develop evidence of mild asthma in response to dust exposure. Diets deficient in omega-3 polyunsaturated fatty acids (Ω-3) might exacerbate this response. HYPOTHESIS: To compare dust exposure, bronchoalveolar lavage fluid (BALF) cytology, and plasma Ω-3 and specialized pro-resolving mediators (SPM) concentrations amongst racehorses fed dry hay, steamed hay, and haylage. ANIMALS: Forty-three Thoroughbred racehorses. METHODS: Prospective clinical trial. Horses were randomly assigned to be fed dry hay, steamed hay, or haylage for 6 weeks. Measures of exposure to dust in the breathing zone were obtained twice. At baseline, week-3, and week-6, BALF cytology was examined. Plasma lipid profiles and plasma SPM concentrations were examined at baseline and week 6. Generalized linear mixed models examined the effect of forage upon dust exposure, BALF cytology, Ω-3, and SPM concentrations. RESULTS: Respirable dust was significantly higher for horses fed hay (least-square mean ± s.e.m. 0.081 ± 0.007 mg/m3 ) when compared with steamed hay (0.056 ± 0.005 mg/m3 , P = .01) or haylage (0.053 ± 0.005 mg/m3 , P < .01). At week 6, BALF neutrophil proportions in horses eating haylage (3.0% ± 0.6%) were significantly lower compared with baseline (5.1 ± 0.7, P = .04) and horses eating hay (6.3% ± 0.8%, P < .01). Plasma eicosapentaenoic acid to arachidonic acid ratios were higher in horses eating haylage for 6 weeks (0.51 ± 0.07) when compared with baseline (0.34 ± 0.05, P < .01) and horses eating steamed (0.24 ± 0.02, P < .01) or dry hay (0.25 ± 0.03, P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: Steamed hay and haylage reduce dust exposure compared with dry hay, but only haylage increased the ratio of anti-inflammatory to pro-inflammatory lipids while reducing BAL neutrophil proportions within 6 weeks.


Assuntos
Poeira , Doenças dos Cavalos , Cavalos , Animais , Estudos Prospectivos , Sistema Respiratório , Líquido da Lavagem Broncoalveolar , Dieta/veterinária
2.
Am J Vet Res ; 83(2): 153-161, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34843444

RESUMO

OBJECTIVE: To investigate the role of omega-3 polyunsaturated fatty acids (Ω-3)-derived proresolving lipid mediators (PRLM) in the resolution of mild airway inflammation in horses. ANIMALS: 20 horses with mild airway inflammation. PROCEDURES: Horses previously eating hay were fed hay pellets (low Ω-3 content; n = 10) or haylage (high Ω-3 content; 9) for 6 weeks. Dust exposure was measured in the breathing zone with a real-time particulate monitor. Bronchoalveolar lavage (BAL) was performed at baseline, week 3, and week 6. The effect of PRLM on neutrophil apoptosis and efferocytosis was examined in vitro. BAL fluid inflammatory cell proportions, apoptosis of circulating neutrophils, efferocytosis displayed by alveolar macrophages, and plasma lipid concentrations were compared between groups fed low and high amounts of Ω-3 by use of repeated measures of generalized linear models. RESULTS: Dust exposure was significantly higher with hay feeding, compared to haylage and pellets, and equivalent between haylage and pellets. BAL fluid neutrophil proportions decreased significantly in horses fed haylage (baseline, 11.8 ± 2.4%; week 6, 2.5 ± 1.1%) but not pellets (baseline, 12.1 ± 2.3%; week 6, 8.5% ± 1.7%). At week 6, horses eating haylage had significantly lower BAL neutrophil proportions than those eating pellets, and a significantly lower concentration of stearic acid than at baseline. PRLM treatments did not affect neutrophil apoptosis or efferocytosis. CLINICAL RELEVANCE: Despite similar reduction in dust exposure, horses fed haylage displayed greater resolution of airway inflammation than those fed pellets. This improvement was not associated with increased plasma Ω-3 concentrations. Feeding haylage improves airway inflammation beyond that due to reduced dust exposure, though the mechanism remains unclear.


Assuntos
Doenças dos Cavalos , Inflamação , Animais , Líquido da Lavagem Broncoalveolar , Poeira , Doenças dos Cavalos/etiologia , Cavalos , Inflamação/veterinária , Lipídeos , Neutrófilos
3.
Vet Immunol Immunopathol ; 237: 110266, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33991760

RESUMO

BACKGROUND: Immunological mechanisms involved in the pathogenesis of mild to moderate equine asthma (MEA) are not completely understood. There are limited data on bronchoalveolar lavage fluid (BALF) and blood inflammatory cytokine profiles in racehorses with MEA, and the effect of racing on inflammatory cytokines is unknown. HYPOTHESIS/OBJECTIVES: We hypothesized that inflammatory cytokine gene expression in BALF and resting blood would be higher in racehorses with lower airway inflammation compared to healthy controls, and that gene expression in blood collected immediately post-race would be increased compared to resting blood in racehorses with lower airway inflammation. ANIMALS: 38 racing Thoroughbreds (samples: 30 resting blood, 22 post-race BALF, 41 post-race blood). METHODS: Prospective observational study. Inflammatory cytokine gene expression was determined in resting blood, post-race BALF and post-race blood from racehorses with lower airway inflammation and controls. RESULTS: Lower airway inflammation was diagnosed in 79 % of racehorses (23 % neutrophilic, 67 % mastocytic, and 10 % mixed). There was no difference in gene expression in BALF or resting blood between racehorses with lower airway inflammation and controls. IL-8 gene expression was higher in post-race blood compared to resting peripheral blood, regardless of disease (p = 0052). BALF neutrophil proportions increased with increasing IL-1ß gene expression in all sample types (p = 0.0025). BALF mast cell proportions increased with increasing TNF-α gene expression in post-race blood (p = 0.015). CONCLUSIONS AND CLINICAL IMPORTANCE: Lower airway inflammation was common in a population of racehorses without respiratory signs or exercise intolerance. Exercise alone increased peripheral blood IL-8 gene expression. Inflammatory cytokine gene expression was not increased in BALF or resting blood in horses with subclinical lower airway inflammation, precluding its diagnostic utility in clinical practice.


Assuntos
Asma Induzida por Exercício/veterinária , Asma/veterinária , Líquido da Lavagem Broncoalveolar/imunologia , Citocinas/genética , Doenças dos Cavalos/genética , Inflamação/veterinária , Animais , Asma/genética , Asma/imunologia , Asma/metabolismo , Asma Induzida por Exercício/genética , Asma Induzida por Exercício/imunologia , Líquido da Lavagem Broncoalveolar/citologia , Expressão Gênica , Doenças dos Cavalos/metabolismo , Cavalos , Inflamação/genética , Inflamação/imunologia , Mastócitos/imunologia , Neutrófilos/imunologia , Esforço Físico/imunologia , Esportes
4.
J Vet Intern Med ; 32(5): 1754-1762, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30222207

RESUMO

BACKGROUND: Mild equine asthma is presumed to arise in response to environmental exposures but the relative impact of differing inflammatory phenotypes upon performance are largely unexplored. HYPOTHESES: Airway inflammation negatively affects performance and cytological phenotype varies with environmental exposure. ANIMALS: Thoroughbred racehorses in active training and racing. METHODS: Thoroughbreds were recruited 24-48 hours before racing. Each horse was eligible for re-enrollment with each race entry. Within one hour of race completion, physical examination, respiratory endoscopy, and BAL were performed. Respirable and inhalable dust, respirable endotoxin, and respirable ß-glucan exposures were measured at the breathing zone within one week after racing. Controlling for age, trainer, and pulmonary hemorrhage, the relationship between performance, bronchoalveolar lavage fluid (BALF) cytology, and measures of exposure were modeled. RESULTS: Performance and BALF data were collected on 64 individual horses from 8 stables for a total of 98 race performances and 79 dust exposure assessments. Evidence of mild equine asthma was found in 80% (78/98) of BALF samples from 52/64 horses. For each percent increase in BALF mast cell and neutrophil proportions, speed figures were reduced by 2.9 (P = .012) and 1.4 (P = .046) points, respectively. Respirable dust concentration was associated with BALF neutrophil proportions (P = .015). Bronchoalveolar lavage fluid mast cell proportions were only associated with respirable ß-glucan exposures (P = .030). CONCLUSIONS AND CLINICAL IMPORTANCE: Mild equine asthma is common in racing horses and negatively impacts performance. The data support that respirable, rather than inhalable, dust exposure measures are pertinent to equine airway health.


Assuntos
Doenças dos Cavalos/patologia , Sistema Respiratório/citologia , Doenças Respiratórias/veterinária , Envelhecimento , Animais , Líquido da Lavagem Broncoalveolar/citologia , Exposição Ambiental , Cavalos , Estudos Prospectivos , Doenças Respiratórias/patologia , Corrida , Esportes
5.
Am J Vet Res ; 67(9): 1519-26, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16948595

RESUMO

OBJECTIVE: To determine synovial fluid gentamicin concentrations and evaluate adverse effects on the synovial membrane and articular cartilage of tarsocrural joints after implantation of a gentamicin-impregnated collagen sponge. ANIMALS: 6 healthy adult mares. PROCEDURES: A purified bovine type I collagen sponge impregnated with 130 mg of gentamicin was implanted in the plantarolateral pouch of 1 tarsocrural joint of each horse, with the contralateral joint used as a sham-operated control joint. Gentamicin concentrations in synovial fluid and serum were determined for 120 hours after implantation by use of a fluorescence polarization immunoassay. Synovial membrane and cartilage specimens were collected 120 hours after implantation and evaluated histologically. RESULTS: Median peak synovial fluid gentamicin concentration of 168.9 microg/mL (range, 115.6 to 332 microg/mL) was achieved 3 hours after implantation. Synovial fluid gentamicin concentrations were < 4 microg/mL by 48 hours. Major histologic differences were not observed in the synovial membrane between control joints and joints implanted with gentamicin-impregnated sponges. Safranin-O fast green stain was not reduced in cartilage specimens obtained from treated joints, compared with those from control joints. CONCLUSIONS AND CLINICAL RELEVANCE: Implantation of a gentamicin-impregnated collagen sponge in the tarsocrural joint of horses resulted in rapid release of gentamicin, with peak concentrations > 20 times the minimum inhibitory concentration reported for common pathogens that infect horses. A rapid decrease in synovial fluid gentamicin concentrations was detected. The purified bovine type I collagen sponges did not elicit substantial inflammation in the synovial membrane or cause mechanical trauma to the articular cartilage.


Assuntos
Antibacterianos/farmacocinética , Artrite Infecciosa/veterinária , Gentamicinas/farmacocinética , Doenças dos Cavalos/metabolismo , Líquido Sinovial/metabolismo , Animais , Antibacterianos/administração & dosagem , Antibacterianos/sangue , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/metabolismo , Cartilagem Articular/patologia , Colágeno Tipo I/farmacologia , Feminino , Gentamicinas/administração & dosagem , Gentamicinas/sangue , Histocitoquímica/veterinária , Doenças dos Cavalos/sangue , Doenças dos Cavalos/tratamento farmacológico , Cavalos , Estatísticas não Paramétricas
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