COMPARISON OF ANTIBIOTIC ADMINISTRATION IN CONJUNCTION WITH SUPPORTIVE MEASURES VERSUS SUPPORTIVE MEASURES ALONE FOR TREATMENT OF DAIRY-COWS WITH CLINICAL MASTITIS
De. Morin et al., COMPARISON OF ANTIBIOTIC ADMINISTRATION IN CONJUNCTION WITH SUPPORTIVE MEASURES VERSUS SUPPORTIVE MEASURES ALONE FOR TREATMENT OF DAIRY-COWS WITH CLINICAL MASTITIS, Journal of the American Veterinary Medical Association, 213(5), 1998, pp. 676
Objective-To determine whether antibiotic and supportive treatment wou
ld improve outcome for dairy cows with naturally developing clinical m
astitis, compared with supportive treatment alone. Design-Randomized c
ontrolled trial. Animals-124 cows in one herd with 172 episodes of cli
nical mastitis. Procedure-Cows were examined at the onset of clinical
mastitis, assigned a severity score, and randomly assigned to receive
antibiotic (intramammary administration of cephapirin, IV administrati
on of oxytetracycline, or both) and supportive treatment (administrati
on of oxytocin, stripping of affected glands, and, in severely affecte
d cows, administration of flunixin meglumine or fluids) or supportive
treatment alone. Treatment was continued until 24 hours after signs of
clinical mastitis resolved (clinical cure). Milk samples from affecte
d glands were submitted for bacterial culture before initial treatment
and every 2 weeks thereafter until the causative organism was no long
er isolated (bacteriologic cure). Results-When mastitis was caused by
Streptococcus spp or coliform bacteria, clinical cure rate by the tent
h milking was significantly higher if antibiotics were used. Bacteriol
ogic cure rate at 14 days was significantly higher when antibiotics we
re used, particularly if mastitis was caused by Streptococcus spp. Cow
s receiving antibiotics developed fewer subsequent episodes of clinica
l mastitis during the 60 days after the initial episode of mastitis an
d had less severe clinical disease than cows that did not. Clinical im
plications-Results suggest that, in herds in which mastitis is often c
aused by environmental bacteria, antibiotic and supportive treatment m
ay result in a better outcome for cows with clinical mastitis than sup
portive treatment alone.