Cephalosporin Treatment for Mastitis
Cephalexin (a first-generation cephalosporin) is the primary oral cephalosporin used to treat mastitis, while cefazolin is the preferred parenteral first-generation option, with ceftiofur (third-generation) reserved for gram-negative infections. 1, 2, 3
First-Generation Cephalosporins as Primary Treatment
Cephalexin is widely recommended for skin and soft tissue infections including mastitis, serving as the standard oral first-generation cephalosporin option. 1
Cefazolin demonstrates superior efficacy among first-generation cephalosporins for treating Staphylococcus aureus mastitis, despite having higher MIC values in vitro compared to cefalonium and cefapirin—highlighting that laboratory susceptibility data does not always predict clinical outcomes. 3
The excipient used for intramammary application significantly influences antimicrobial efficacy; miglyol 812 improves cefazolin's effectiveness compared to mineral oil formulations. 3
Treatment Selection Based on Pathogen
For gram-positive mastitis pathogens (including S. aureus, coagulase-negative staphylococci, and streptococci): First-generation cephalosporins like cephapirin sodium or cephalexin achieve bacteriological cure rates of 90% or higher and demonstrate noninferiority to third-generation agents. 2, 4
For gram-negative mastitis (particularly E. coli and Klebsiella spp.): Third-generation cephalosporins like ceftiofur hydrochloride show significantly higher bacteriological cure rates compared to first-generation agents. 4
Cefoperazone (third-generation) is commonly used for bovine mastitis therapy when broader gram-negative coverage is required. 5
Combination Therapy Considerations
Cefalexin combined with kanamycin (1:1.5 ratio) provides rapid bacterial killing against major mastitis pathogens at concentrations achievable via intramammary infusion, with faster and greater kill than either drug alone. 6, 7
The combination demonstrates effectiveness against S. aureus, E. coli, Streptococcus agalactiae, S. dysgalactiae, and S. uberis at both tested concentration ratios. 7
Clinical Application Algorithm
For nonsevere clinical mastitis:
- Identify the likely pathogen based on clinical presentation and farm history
- If gram-positive infection suspected (most common): Use cephapirin sodium (2 treatments 12 hours apart) or cephalexin orally 4
- If gram-negative infection suspected or confirmed: Use ceftiofur hydrochloride (once daily for 5 days) 4
- Consider combination cefalexin/kanamycin for mixed or severe infections 6, 7
Important Caveats
Avoid cephalosporins in patients with history of anaphylaxis, angioedema, or urticaria to penicillins due to potential cross-reactivity. 1, 2
Cephalexin is inappropriate for severe or life-threatening infections requiring parenteral therapy during the acute phase. 2
Streptococcus dysgalactiae is the most commonly identified pathogen in mild to moderate clinical mastitis, followed by E. coli. 4