Use of Antimicrobials in the Treatment of Reproductive Diseases in Cattle and Horses

Abstract

Use of antimicrobials for veterinary indications related to reproduction in cattle and horses is reviewed. Antimicrobial compounds are widely used to treat and prevent infections of reproductive organs. Total amounts of antimicrobials for such purposes, estimated by weight, are low compared with major uses in food animals. The most common reproduction-related indication in cattle is mastitis. The number of intramammary products available for treatment of mastitis in the European Union is high. Metritis and endometritis also require antimicrobial treatment of cattle and specific products for intrauterine administration are available. The traditions and practices associated with the use of these products vary considerably among different countries. Parenteral antimicrobial treatment is used to treat acute clinical mastitis and puerperal metritis. Pharmacological characteristics of the antimicrobial administered parenterally are critical to achieve and maintain therapeutic concentrations in the target organs. In mares, the most common indications associated with reproduction are endometritis, retained placenta and placentitis. The number of authorized antimicrobial products for horses is limited. Horses are treated individually and off-label use of antimicrobials is very common. In veterinary indications related to reproduction, treatment practices exist that cannot be considered to be evidence-based or responsible use of antimicrobials. Not all products for local treatment have proven efficacy data. Examples of unnecessary uses are routine treatment of cows with retained placenta and use of post-breeding antibiotic treatments in mares.

Characterization of Staphylococcus spp. strains in milk from buffaloes with mastitis in Brazil: the need to identify to species level to avoid misidentification

“…Additionally, only the S. aureus isolates were resistant to penicillin, ampicillin, and intermediate levels of erythromycin. This finding is not surprising as these antimicrobials are commonly used to treat mastitis (Pyörälä et al, 2014) and thus may contribute for the selection of these resistant strains. Even though, in this work, the mecA gene was not detected in any of the strains, using the protocol of Santos et al, (1999); methicillinresistant staphylococci have already been reported as bovine mastitis agents (Seixas et al, 2014) and attention should be paid to monitor the presence of this antimicrobial resistance gene.…”

“…The disease is classified as moderate or severe, and might be caused by different bacterial species, but mainly Staphyococcus strains (Pyörälä and Taponen, 2009 Coagulase-negative staphylococci (CNS) have been considered pathogens of lesser importance, while Staphylococcus aureus has been considered a more important pathogen due its ability to form biofilm (Lee et al, 2014). However, more recent studies have shown that CNS are emerging pathogens associated with the occurrence of mastitis and persistence of intramammary infection in dairy cattle (Fry et al, 2014).…”

Update on endometritis therapy

“…More antibiotics are available for systemic use, but the pharmacokinetic properties are not always suited for uterine infections. In general, high lipid solubility, low protein binding and a high degree of nonionization favor distribution throughout the body (Pyörälä et al 2014).…”

“…Tetracyclines have moderate lipidsolubility and can yield therapeutic concentrations in reproductive organs. However, because of their side-effects tetracyclines are not commonly used in horses (Pyörälä et al 2014). In a Swedish study, enrofloxacin was the only of 10 tested antibiotics for which no E. coli isolate was resistant but 15 % of E. coli isolates were resistant to trimethoprim/sulphamethoxazole, 22 % to streptomycin, 11% to ampicillin and 4 % to gentamicin (Albihn et al 2003).…”

“…Their penetration into cells and tissues is generally poor via systemic route (Hagget and Wilson 2008), but gentamicin has been shown to be transferred to the placenta (Pyörälä et al 2014). Aminoglycocide activity is predominantly limited to aerobic Gram-negative bacteria and they have good activity also against Pseudomonas spp.…”