Inflammatory airway disease, nasal discharge and respiratory infections in young British racehorses.

Authors: Wood J L N, Newton J R, Chanter N, Mumford J A

Journal: Equine veterinary journal

DOI: 10.2746/0425164054530579 PubMed: 15892233Log in to save

Summary

# Inflammatory Airway Disease in Young British Racehorses: Prevalence, Incidence and Clinical Significance Respiratory disease significantly impacts the performance and welfare of young Thoroughbreds in training, yet previous characterisation of disease rates across different age groups and training establishments has been limited. Over a three-year period, researchers examined horses monthly across seven British flat racing yards, defining inflammatory airway disease (IAD) as increased tracheal mucus with elevated neutrophil proportions in tracheal wash samples, and recorded the prevalence and incidence of IAD, nasal discharge, and evidence of bacterial and viral infection. The study found IAD prevalence of 13.8% with an incidence of 8.9 cases per 100 horses per month, with rates varying significantly between training groups and declining markedly in older animals; nasal discharge occurred in 4.1% of cases, whilst bacterial isolations were more frequently detected than viral infections, and bacterial species prevalence similarly decreased with age. Given the high prevalence of IAD in two-year-olds, routine endoscopic examination warrants consideration as a practical diagnostic tool for early identification and targeted therapeutic intervention. The multifactorial nature of the disease—encompassing infection, stable management, individual genetic susceptibility and environmental factors—underscores the need for integrated approaches to disease prevention and highlights the importance of understanding pathogen transmission dynamics within and between training groups.

Read the full abstract on PubMed

Practical Takeaways

•Routine endoscopic examination of 2-year-old racehorses may enable early diagnosis and intervention for the common condition of IAD
•Environmental and management factors between training yards influence respiratory disease rates, suggesting that stable conditions and group dynamics warrant attention
•Younger horses are at higher risk of respiratory disease and associated bacterial/viral infections, requiring age-appropriate monitoring protocols

Key Findings

•IAD prevalence was 13.8% with incidence of 8.9 cases/100 horses/month in young British racehorses
•Nasal discharge prevalence was 4.1%, with both IAD and ND rates decreasing significantly with age
•Bacterial isolation was more common than viral infections, with bacterial species incidence declining with age
•Disease rates varied significantly between different training groups, consistent with infection playing a role in aetiology

Conditions Studied

inflammatory airway disease (iad)nasal dischargerespiratory infectionsbacterial infectionsviral infections

Related References

Descriptive results from a longitudinal study of airway inflammation in British National Hunt racehorses.

Cardwell J M, Wood J L N, Smith K C, Newton J R(2011)Equine veterinary journal

Lower respiratory tract disease in Thoroughbred racehorses: analysis of endoscopic data from a UK training yard.

Ramzan P H L, Parkin T D H, Shepherd M C(2008)Equine veterinary journal

Airway inflammation and mucus in two age groups of asymptomatic well-performing sport horses.

Gerber V, Robinson N E, Luethi S, Marti E, Wampfler B, Straub R(2003)Equine veterinary journal

What's in a name? Inflammatory airway disease in racehorses in training.

Cardwell J M, Christley R M, Gerber V, Malikides N, Wood J L N, Newton J R, Hodgson J L(2011)Equine veterinary journal

Equine Rhinitis A Virus Infection at a Standardbred Training Facility: Incidence, Clinical Signs, and Risk Factors for Clinical Disease.

Rossi Tanya M, Moore Alison, O'Sullivan Terri L, Greer Amy L(2019)Frontiers in veterinary science