Retrospective study of the relationships between age, inflammation and the isolation of bacteria from the lower respiratory tract of thoroughbred horses.
A total of 1235 tracheal aspirates taken from 724 thoroughbreds in race training, aged from two to 10 years, were examined cytologically and bacteriologically. An inflammation scoring system on a scale of 0 to 9 was devised to allow the severity of lower airway disease to be assessed from the cytological results. The inflammation scores were closely related to the isolation of bacteria (P<0.001), and the most common bacterial isolates were Streptococcus zooepidemicus, Streptococcus pneumoniae and Pasteurella/Actinobacillus-like species. Lower airway disease was less common in older horses (P = 0.031), and the groups at highest risk were the two- and four-year-olds. Lower airway inflammation was more common in the four-year-olds at National Hunt yards than in the four-year-olds at flat racing yards (P = 0.040, odds ratio = 3.80).
Chapman
P S
PS
Department of Farm Animal and Equine Medicine and Surgery, Royal Veterinary College, North Mymms, Hertfordshire.
Green
C
C
Main
J P
JP
Taylor
P M
PM
Cunningham
F M
FM
Cook
A J
AJ
Marr
C M
CM
D000188:Actinobacillus / Q000302:isolation & purification; D000189:Actinobacillus Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary; D000367:Age Factors; D000818:Animals; D005260:Female; D006734:Horse Diseases / Q000382:microbiology* / Q000473:pathology; D006736:Horses; D007249:Inflammation; D008297:Male; D010325:Pasteurella / Q000302:isolation & purification; D010326:Pasteurella Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D012189:Retrospective Studies; D013290:Streptococcal Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D018502:Streptococcus equi / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000302:isolation & purification