• Penicillin (Na+ or K+ Salt)  (K-Penn)
  5 million units
  Very effective for streptococci; economical and commonly used
• Ampicillin
  1-3 g
  Use at high dilutions because it can be irritating; NA+ salt leaves precipitate on endometrium that remains in uterus for prolonged period
• Carbenicillin
  2-5 g
  Reserved for persistent Pseudomonas (synergistic efficacy with amino-glycosides); usually given on alternate days with amino-glycosides; slightly irritating
  
   

Antibiotics for Gram Negative Bacteria

• Gentamicin Sulfate
  500-1000 mg
  Highly effective; generally nonirritating when mixed with an equal volume of NaHCO3 and diluted in saline
   
• Amikacin Sulfate
  2 g
  Use for Pseudomonas, Klebsiella, and persistent gram-negative organisms
   
• Kanamycin Sulfate
  1 g
  Toxic to spermatozoa; do not use close to breeding
• Polymyxin B
  1 million units
  Gram-negative infections, particularly Pseudomonas
• Neomycin Sulfate
  3-4 g
  Use for sensitive E. Coli; can be irritating; post breeding use of oral preparations containing neomycin mixed with other antimicrobials has lowered pregnancy rates in mares
• Nitrofurazones
  50-60 ml
  Highly questionable effectiveness
  
   

Antibiotics for Gram Positive & Negative Bacteria

• Cephazolin Sodium
  1 g
  First-generation cephalosporin; has been used empirically once daily intramuscularly for 2-3 weeks; broad spectrum effectiveness against Gram-positive and Gram-negative bacteria
• Ticarcillin
  1-3 g
  Use for Pseudomonas; do not use for Klebsiella
• Naxcel (Ceftiofur Sodium)
  1 g
  Third-generation cephalosporin; has been used empirically once daily either intramuscularly or by intrauterine infusion; broad-spectrum effectiveness against Gram-positive and Gram-negative bacteria
• Povidone-Iodine
  (1%-4% of stock solution of Betadine, which is 0.5% Povidone iodine)
  1 liter (lavage solution)
  If solutions are too concentrated (e.g., >5% Betadine v/v), severe endometritis results and/or neutrophil function is impaired; in vitro bactericidal activity is maintained at concentrations as low as 0.01%-0.005%; indicated for lavage of uteri with nonspecific inflammation or fungal/yeast infections; should not be left in uterus
   

Yeast Specific Drugs

• Nystatin
  500,000 units
  Primarily for yeast (e.g., Candida albicans) in the growing phase; dilute in 100 t0 250 ml sterile water--makes an insoluble suspension that must be vigorously mixed immediately prior to infusion
• Amphotericin B
  200 mg
  For infections with Aspergillus, Candida, Mucor, or Histoplasma; dilute in 100 to 250 ml sterile water--makes a relatively insoluble suspension
• Clotrimazole
  700 mg
  For yeast infections (Candida spp.); available as cream, tablets, or suppositories; preferable treatment is with tablets crushed and mixed with 40 ml sterile water; generally infused after uterine lavage
• Miconazole
  200 mg
  Most efficacious for yeast infections (Candida spp.), but has been used by some practitioners for resistant fungal infections in mares by infusing once daily for up to 10 days; dilute in 40-6- ml sterile saline prior to infusion
   

Drugs for Aggressive Reproductive Management

• Dimethylsulfoxide  (DMSO)
  (5% of stock solution)
  50-100 ml
  Used as penetrating agent to carry drugs; effectiveness and safety unknown
   
• EDTA-TRIS (1.2 g NaEDTA + 6.05 g TRIS/L of H20, titrated to pH 8.0 with glacial acetic acid)
  250 ml, then infuse antibiotic 3 hours later
  EDTA theoretically binds Ca++ in bacterial cell walls, making cell wall permeable to antibiotic and thus more susceptible; use confined to persistent Pseudomonas infections