Equine astma: huidige kennis van zaken

Equine astma is de overkoepelende term voor een inflammatoir proces ter hoogte van de diepere luchtwegen. Deze aandoening wordt verder onderverdeeld in lichte tot matige astma, beter bekend als “inflammatory airway disease” (IAD), en ernstige astma, beter bekend als “recurrent airway obstruction” (RAO). RAO veroorzaakt inflammatie en obstructie van de diepe luchtwegen, wat leidt tot chronische hoest, verhoogde ademhalingsinspanning in rust en inspanningsintolerantie, meestal bij paarden ouder dan zeven jaar. IAD daarentegen kan op elke leeftijd voorkomen en de klinische tekenen zijn vaak veel subtieler, namelijk verminderd presteren en occasioneel hoesten. Equine astma wordt voornamelijk getriggerd door een hoge concentratie aan stof en schimmelsporen in de stalomgeving of pollen tijdens de zomermaanden in het geval van “summer pasture associated” RAO (SPARAO). De gouden standaard om equine astma te diagnosticeren is het uitvoeren van een endoscopie, gevolgd door een broncho-alveolaire lavage (BAL). Het aanpassen van de omgeving is en blijft de belangrijkste behandelingsmethode, vaak in combinatie met het tijdelijk toedienen van corticosteroïden en bronchodilatatoren.

Equine astma: huidige kennis van zaken

Equine astma is de overkoepelende term voor een inflammatoir proces ter hoogte van de diepere luchtwegen. Deze aandoening wordt verder onderverdeeld in lichte tot matige astma, beter bekend als “inflammatory airway disease” (IAD), en ernstige astma, beter bekend als “recurrent airway obstruction” (RAO). RAO veroorzaakt inflammatie en obstructie van de diepe luchtwegen, wat leidt tot chronische hoest, verhoogde ademhalingsinspanning in rust en inspanningsintolerantie, meestal bij paarden ouder dan zeven jaar. IAD daarentegen kan op elke leeftijd voorkomen en de klinische tekenen zijn vaak veel subtieler, namelijk verminderd presteren en occasioneel hoesten. Equine astma wordt voornamelijk getriggerd door een hoge concentratie aan stof en schimmelsporen in de stalomgeving of pollen tijdens de zomermaanden in het geval van “summer pasture associated” RAO (SPARAO). De gouden standaard om equine astma te diagnosticeren is het uitvoeren van een endoscopie, gevolgd door een broncho-alveolaire lavage (BAL). Het aanpassen van de omgeving is en blijft de belangrijkste behandelingsmethode, vaak in combinatie met het tijdelijk toedienen van corticosteroïden en bronchodilatatoren.

Equine asthma: managing the environment

Equine asthma is an umbrella term defined by nonseptic lower airway inflammation. Currently there are two broad categories, namely mild to moderate equine asthma (formerly known as inflammatory airway disease) and severe equine asthma (formerly known as recurrent airway obstruction or heaves). Environmental challenge is involved in the aetiopathogenesis of both these subcategories. Much of this challenge, and the part that we can control, is provided by the organic dust associated with the stabling of horses. This article reviews the available evidence relating to the environmental management of equine asthma and tries to relate this to practical options for providing a low-dust environment.

Assessment of serum allergen-specific IgE levels in horses with seasonal allergic dermatitis and recurrent airway obstruction in Spain

Allergic conditions are prevalent equine diseases that can be diagnosed by clinical examination alone, but definitive diagnosis is more likely with laboratory testing. The ELISA Allercept© test was used to analyse the serum samples of 73 horses with allergic diseases. Sixty-one horses (83.5%) had allergen-specific IgE levels ≥ 150 ELISA Units (EU), the cut-off defined by the assay. Fifty-four horses had allergic dermatitis (AD) with high IgE levels to Tyrophagus putrescentiae (51.9%), Rumex crispus (48.1%), Tabanus (46.3%) and Dermatophagoides farinae/ D. pteronyssinus (40.7%). Seven horses with recurrent airway obstruction (RAO) had a high prevalence of T. putrescentiae (85.7%), followed by that of Acarus siro (57.1%) and D. farinae/D. pteronyssinus (57.1%). Horses affected with RAO had more positive reactions to mites (2.22 ± 0.84) than did horses with AD (1.51 ± 0.61, P < 0.05). A strong correlation of serum allergen-specific IgE level was found between Culex tarsalis and Stomoxys (r = 0.943) and between Dactylis glomerata and both Secale cereale (r = 0.79) and R. crispus (r = 0.696). These results indicate that among horses with allergic diseases in Spain, ELISA tests demonstrated a high prevalence of serum allergen-specific IgE in response to mites. Our study emphasises the importance of laboratory testing and updating allergy panels to improve the likelihood of a definitive diagnosis and the identification of allergens that should be included in allergic disease treatment.

Lung lesions of slaughtered horses in southern Brazil

ABSTRACT: Respiratory diseases cause significant veterinary costs, reduce performance and require withdrawal of horses. Yet, studies of the causes of pneumonia in horses are scant. This study aimed to describe the pathological and microbiological features of lung lesions in slaughtered horses in southern Brazil. In this study, 84 samples of lungs were examined, and a conclusive diagnosis was obtained in 74 cases. These were composed of bronchopneumonia in 50 cases, followed by granulomatous eosinophilic pneumonia (9/74), recurrent airway obstruction (7/74), lung fibrosis (4/74), lung hemorrhage (3/74) and pulmonary pythiosis (1/74). Bronchopneumonia had grossly firm focally extensive yellow to dark-red areas, which consisted microscopically of multifocal to coalescing infiltrate of degenerate neutrophils. Streptococcus equi subsp. zooepidemicus was identified in 21 of the 50 cases. Granulomatous eosinophilic pneumonia had multifocal pinpoint firm-hard yellow areas, which microscopically were composed of granulomas with a mineralized center surrounded by collagen fibers and severe infiltrate of eosinophils. Recurrent airway obstruction had mild multifocal pinpoint firm white areas that consisted microscopically of large amounts of mucus inside bronchi and bronchiole. Lung fibrosis had two patterns: focally extensive areas of consolidation and firm nodular areas. Microscopically, the first pattern had interstitial to peribronchial fibrosis, while the second had, in addition to the interstitial fibrosis, a severe pneumocyte hyperplasia and an alveolar infiltrate of neutrophils and macrophages with rare intranuclear inclusion bodies (equine herpesvirus 5, EHV-5). Pulmonary pythiosis presented a focal firm nodular area, with multiple kunkers observed in the cut surface, which corresponded microscopically to areas of necrosis surrounded by a mixed inflammatory infiltrate. At the periphery of the necrotic areas, multiple negatively stained hyphae were observed, which were evidenced through Grocott’s stain and immunohistochemistry anti-Pythium insidiosum.

In an Adult Horse With Severe Asthma (Previously Recurrent Airway Obstruction) Does Using Inhaled Corticosteroids Result in an Equal Improvement in Clinical Signs When Compared to Systemic Corticosteroids?

<strong>PICO question</strong><br /><p>In an adult horse with severe asthma (previously recurrent airway obstruction (RAO)) does using inhaled corticosteroids result in an equal improvement in clinical signs when compared to systemic corticosteroids?</p><strong>Clinical bottom line</strong><br /><p>The level of confidence in the outcomes from the body of evidence in the 4 papers identified is high. This suggests inhaled corticosteroids (fluticasone and beclomethasone) when used at an appropriate dose can have equivalent effects on severe equine asthma as systemic intravenous dexamethasone. Inhaled corticosteroids can take longer to have the desired effects. </p><br /> <img src="https://www.veterinaryevidence.org/rcvskmod/icons/oa-icon.jpg" alt="Open Access" /> <img src="https://www.veterinaryevidence.org/rcvskmod/icons/pr-icon.jpg" alt="Peer Reviewed" />