Effects of a single dose of enrofloxacin on body temperature and tracheobronchial neutrophil count in healthy Thoroughbreds premedicated with interferon-α and undergoing long-distance transportation.
OBJECTIVE
To evaluate effects of a single dose of enrofloxacin (5 mg/kg, IV) on body temperature and tracheobronchial neutrophil count in healthy Thoroughbreds premedicated with interferon-α and undergoing long-distance transportation.


METHODS
32 healthy Thoroughbreds.


METHODS
All horses received interferon-α (0.5 U/kg, sublingually, q 24 h) as an immunologic stimulant for 2 days before transportation and on the day of transportation. Horses were randomly assigned to receive enrofloxacin (5 mg/kg, IV, once; enrofloxacin group) or saline (0.9% NaCl) solution (50 mL, IV, once; control group) ≤ 1 hour before being transported 1,210 km via commercial vans (duration, approx 26 hours). Before and after transportation, clinical examination, measurement of temperature per rectum, and hematologic analysis were performed for all horses; a tracheobronchial aspirate was collected for neutrophil quantification in 12 horses (6/group). Horses received antimicrobial treatment after transportation if deemed necessary by the attending clinician.


RESULTS
No adverse effects were associated with treatment. After transportation, WBC count and serum amyloid A concentration in peripheral blood samples and neutrophil counts in tracheobronchial aspirates were significantly lower in horses of the enrofloxacin group than in untreated control horses. Fever (rectal temperature, ≥ 38.5°C) after transportation was detected in 3 of 16 enrofloxacin group horses and 9 of 16 control horses; additional antimicrobial treatment was required in 2 horses in the enrofloxacin group and 7 horses in the control group.


CONCLUSIONS
In horses premedicated with interferon-α, enrofloxacin appeared to provide better protection against fever and lower respiratory tract inflammation than did saline solution.
Hidaka Training and Research Center, Japan Racing Association, 535-13, Nishicha, Urakawa-chou, Urakawa-gun, Hokkaido 057-0171, Japan. gagner.prix.de.l.arc.de.triomphe@gmail.com
Takeru
T
Tsuchiya
Seiji
S
Hobo
Yoshiro
Y
Endo
Shoichi
S
Narita
Koji
K
Sakamoto
D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D001831:Body Temperature / Q000187:drug effects; D000077422:Enrofloxacin; D005260:Female; D024841:Fluoroquinolones / Q000008:administration & dosage*; D006736:Horses / Q000097:blood / Q000502:physiology*; D016898:Interferon-alpha / Q000008:administration & dosage*; D007958:Leukocyte Count / Q000662:veterinary; D008297:Male; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects*; D012137:Respiratory System / Q000166:cytology / Q000187:drug effects*; D000685:Serum Amyloid A Protein / Q000378:metabolism; D014186:Transportation
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D016898:Interferon-alpha; D000685:Serum Amyloid A Protein; D000077422:Enrofloxacin