2009: Antibiotics in mare reproduction Antibiotics in mare reproduction 1 J.J. Dascanio 2 Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Phase II, Duck 3 Pond Drive, Blacksburg, VA, USA 4 Abstract 5 Antibiotics are used to treat a variety of reproductive tract infections in the mare. The 6 results of an on-line survey of veterinarians concerning the use of antibiotics in mare 7 reproduction are presented. Listservs were used to acquire the data. Most veterinarians follow 8 the recommendations in the literature for treating mares with reproductive tract infections. 9 However, some veterinarians may mix antibiotics inappropriately, treat mares too soon after 10 breeding, use inappropriate mixed lavage solutions, or use antibiotics in cases that do not warrant 11 their use. 12 Keywords: Mare, antibiotic, reproduction, uterine, systemic, fungal 13 Introduction 14 Antibiotics are used in the mare to treat potential or realized reproductive tract infections 15 including vaginitis, cervicitis, endometritis, metritis, pyometra, and placentitis. Alternatively, 16 infections may be associated with or classified as sexually transmitted diseases, post-mating 17 induced endometritis, acute or chronic endometritis, abortion related, and/or bacterial and fungal 18 infections.1 Antibiotics are administered either through intravenous/intramuscular routes or 19 directly into the reproductive tract lumen. Antibiotics are naturally occurring or synthetic 20 substances that inhibit the growth of or kill microorganisms. The definition may be limited to 21 substances affecting bacteria or may also include fungi and protozoa. In this paper antifungals 22 will be considered part of the antibiotic class. 23 411 There are a few reviews of the use of antibiotics in mare reproduction.2-4 The choice of 24 antibiotic should be based on culture and sensitivity patterns when possible or based on the most 25 likely organism when not possible. The most common bacteria isolated from the mare’s 26 reproductive tract are Streptococcus equi subspecies zooepidemicus (Gram positive), Escherichia 27 coli (Gram negative), Klebsiella pneumonia (Gram negative), Pseudomonas aeruginosa (Gram 28 negative), Staphylococcus aureus (Gram positive), and Bacteroides (Gram negative, anaerobe).5-29 10 Streptococcus equi subspecies zooepidemicus and Escherichia coli are the number one and 30 two isolates in almost all reports. The most common fungi isolated from the mare’s reproductive 31 tract are Candida spp and Aspergillus spp.11 32 There are many factors that may affect antibiotic effectiveness/clearance such as 33 overwhelming microorganism numbers, presence of uterine fluid/debris, lack of uterine 34 contractility, use of ecbolics, normality of uterine mucocilliary clearance mechanisms, cervical 35 dilation, and dependency of the uterine horns.12-15 Disruptions of natural barriers to infection, 36 such as previous cervical trauma/scarring, vestibulovaginal fold incompetence (windsucker), and 37 poor vulvar conformation, may also contribute to continued bacterial/fungal contamination.16 38 Intrauterine antibiotic therapy appears to have decreased in use, most likely due to 39 concerns about inducing secondary fungal infections and/or antibiotic resistance and due to new 40 information on the effectiveness of uterine lavage and the use of ecbolics, such as oxytocin and 41 prostaglandin. Antibiotic therapies are now more targeted at specific organisms, are used with 42 more specific disease processes or are used in conjunction with methods to disrupt biofilms or 43 after decreasing bacterial numbers with lavage techniques. This manuscript will describe the 44 results of an on-line survey of veterinarians concerning antibiotic use in mare reproduction and 45 correlate the results to the literature. 46 412 Survey on antibiotic usage 47 Two surveys were conducted with regards to the use of antibiotics in equine 48 reproduction. The surveys were initiated to see what is commonly used in practice vs. what is 49 recommended in the literature. Both surveys were sent to the Equine Clinicians Network listserv 50 (ecn@listserv.vetmed.wsu.edu), the American Association of Equine Practitioner’s listserv 51 (aaep_discussion@list.aaep.org), the Equine Reproduction listserv (eqrepro-l@po.missouri.edu) 52 and the American College of Theriogenologists listserv (ACTList@lists.theriogenology.org). 53 The first was initiated in September 2008 (190 respondents) and the second was initiated in 54 March 2009 (109 respondents). The second survey was performed to augment the first survey 55 results. Sixty-one percent of participants in the second survey partook in the first survey. 56 Approximately 69% of survey participants stated that the primary way that mares are 57 bred in their practice is by the use of fresh cooled semen, 27% are bred primarily by natural 58 cover, 3% primarily with frozen semen and 2% did not provide an answer. The number of years 59 in practice was: <5 years – 7%, 5 to 10 years – 20%, 11 to 15 years – 13%, 16 to 20 years – 18%, 60 >20 years – 39%, no answer – 2%. The percentage of their practice that was devoted to equine 61 reproduction was: <10% - 11%, 10 to 25% - 21%, 25 to 50% - 18%, 50 to 75% - 15%, >75% - 62 34%, no answer – 1%. The larger number of practitioners in the >75% category most likely 63 reflects the distribution of the survey to two predominately reproductively oriented listservs 64 (ACT and EqRepro). Veterinarians from 14 countries participated in the survey, with 70% of 65 respondents practicing in the United States. 66 When asked which bacterial and fungal organisms they encountered most frequently, the 67 overwhelming answers for bacterial isolates were Streptococcus zooepidemicus followed by 68 Escherichia coli. One practice stated that they had 80% beta-hemolytic Streptococcus isolated 69 413 from 1400 uterine cultures in their clinic. An antibiotic with both Gram positive and Gram 70 negative properties may be appropriate for the treatment of uterine infections in those cases 71 without culture. Fungal cultures, according to survey results, yielded primarily Candida spp 72 followed secondarily by Aspergillus spp. 73 Intrauterine usage of antibiotics. 74 Antibiotics may be placed into the uterus prior to or after breeding or in association with 75 treatment of suspected or known uterine infections. Dosages for antibiotics commonly used for 76 intrauterine infusion are presented in Table 1. Practitioners responding to the survey stated that 77 antibiotics administered prior to breeding were used for mares that were known to be problem 78 breeders, mares that were repeat breeders, mares with uterine fluid pre-breeding, mares with 79 excessive uterine edema, mares suspected of having an infection (awaiting culture/cytology 80 results), mares suspected of having an infection (owners decline culture/cytology) or strictly at 81 the owner’s request. 82 Survey participants stated that they used post-breeding antibiotics in situations where 83 they knew the mare had previous problems, in mares with uterine fluid, in those mares 84 susceptible to post-mating induced endometritis, in mares bred late in the breeding season, in 85 mares with previous pregnancy loss or as a routine procedure with a single dose of antibiotics, 86 especially in natural cover situations. A study by Pycock found that pregnancy rates were better 87 after a single dose of antibiotics (± oxytocin) post-breeding, especially in older mares (>12 88 years) and mares mated at the first estrus post-partum.17 Some Thoroughbred farms may 89 routinely use a single post-breeding antibiotic to limit bacterial contamination from natural 90 cover.18 91 414 When asked how many days mares were commonly treated with intrauterine antibiotics, 92 the responses were: one day (12%), two days (7%), three days (50%), four days (5%), five days 93 (7%), one week (1%), other (13%), and no answer (5%). Those answering “other” may treat for 94 1 to 3 days, 3 to 5 days, number of days would depend on bacteria isolated, number of days 95 would depend on presence of fluid, or would never treat a mare with intrauterine antibiotics. It 96 has been recommended, based on endometrial biopsy, that treatment for mild intrauterine 97 infections be performed for 3 days, moderate infections for 5 days, and severe infections for 7 98 days.12 The determination of how mares fit into these categories may not be clear in practice and 99 would need to be subjectively based on clinical signs and possible cytologic examination as 100 biopsy results may not be returned for a number of days. It has also been suggested that mares 101 not be treated for more than 2 or 3 days post-ovulation so as to decrease possible negative effects 102 on corpus luteum progesterone secretion from prostaglandin released in response to endometrial 103 irritation caused by the antibiotic or vehicle.12 Antibiotics should also not be used immediately 104 pre-breeding as high concentrations of antibiotics may negatively affect sperm function.12 105 Forty-three percent of practitioners would increase the volume of antibiotic solution 106 infused to between 50 to 100 ml prior to infusion. Eight percent used the antibiotic without 107 dilution; 19% added extra volume, but kept the total less than 50 ml; 11% added extra liquid so 108 that the final volume was >100 ml; 7% added the antibiotic to the lavage solution; 6% did not 109 answer the question; and 8% provided an alternative answer of “other” which included leaving 110 some lavage solution in the uterus and adding the antibiotic to that fluid, using a 250 ml bottle of 111 fluid for infusion with antibiotics added, or using a 10 ml or 20 ml total volume. The literature 112 has suggested intrauterine infusion volumes ranging from 30 to 200 ml to achieve distribution 113 throughout the uterine lumen.2 Six grams of ticarcillin, for instance, has a higher intrauterine 114 415 concentration over time when a 250 ml volume is infused rather than a 60 ml volume.19 With 115 large volumes, however, reflux of fluid back through the cervix could occur, diminishing the 116 overall dose. A more appropriate recommendation may be to maximize the volume of an 117 antibiotic solution while considering the relative size and position of the uterus. Multiparous 118 mares would naturally require a larger volume, while nulliparous mares should require less. 119 With a dependant uterus, infused fluids tend to pool in the base of the uterine horns making it 120 difficult to achieve uniform coverage of the endometrium; consequently, systemic antimicrobials 121 may be a good choice in these mares. 122 The most common antibiotic used for intrauterine treatment prior to receiving 123 culture/antibiotic sensitivity results by veterinarians who participated in the survey was ceftiofur 124 (21%), followed by gentamicin (19%), ticarcillin with clavulanic acid (13%), ampicillin (12%), 125 other (12%), procaine penicillin (5%), amikacin (5%), potassium penicillin (3%), and ticarcillin 126 (3%). Nine percent of survey participants did not answer this question. The category “other” 127 included combination of penicillin and gentamicin (2%), penicillin and neomycin (2%), 128 ampicillin and gentamicin (1%), oxytetracycline, framomycin, framycetin, cefquinome, 129 cefazolin, or chloramphenicol. Interestingly, procaine penicillin was used even though there are 130 no dosages reported in most published reviews. Some practitioners had concern about residues 131 that may be left within the uterus with the use of the procaine penicillin suspension. 132 Enrofloxacin has been administered by intrauterine infusion without causing more than a 133 moderate inflammatory response,20 but there are other reports that the basic pH of enrofloxacin is 134 very irritating to the endometrium.12 Differences among reports may be due to the formulation 135 studied in various countries and dosage, thus caution should be exerted when considering 136 intrauterine enrofloxacin or, alternatively, enrofloxacin should be used systemically. 137 416 If we examine some of the more common antibiotics used in practice, one study found 138 that 19% of beta-hemolytic Streptococcus isolates (includes Streptococcus zooepidemicus) were 139 susceptible to gentamicin, whereas 96% of Escherichia coli isolates were susceptible.10 In that 140 study, 100% of the beta-hemolytic Streptococcal isolates were susceptible to ampicillin and 141 penicillin G, whereas 86% of Escherichia coli isolates were susceptible to ampicillin. Another 142 study evaluated intrauterine ceftiofur in mares and found that the drug had good antimicrobial 143 activity and caused no increase in uterine inflammation when compared to controls.21 Ticarcillin 144 with clavulanic acid has been evaluated for intrauterine use and it was found that adequate 145 intrauterine concentrations of the clavulanic acid portion are not maintained. Thus, this 146 formulation may be questionable for intrauterine use.22 These authors also reported that 147 concentrations of ticarcillin declined rapidly after intrauterine administration, and multiple daily 148 doses would be required. 149 Aminoglycosides have an acid pH that will irritate the endometrium.3 It is suggested that 150 aminoglycosides be buffered to a neutral pH with an equal volume of 7.5% sodium bicarbonate. 151 Forty-three percent of practitioners added sodium bicarbonate, while 38% increased the volume 152 of infusion as a means to moderate the acidic effects, and 10% did not add anything to the 153 aminoglycoside. If saline is used to increase the volume of infusion to reduce the effect of low 154 pH, it should be noted that saline has a pH of ≈5.5. A more suitable diluent may be lactated 155 Ringer’s solution which has a neutral pH. 156 Aminoglycosides should not be mixed with beta-lactam antibiotics. Precipitates may 157 form when they are combined or, more importantly, aminoglycosides may cause a nucleophilic 158 opening of the beta-lactam ring which then combines with an amino group from the 159 aminoglycoside, resulting in a biologically inactive amide.23,24 While the two drugs are 160 417 synergistic in controlling Gram positive (beta-lactams) and Gram negative (aminoglycosides) 161 infections when given systemically, it is not completely understood how effective they are when 162 placed together into the uterine lumen. In addition, penicillin G (potassium or procaine) is 163 inactivated by acids, so if penicillin and an aminoglycoside are used together in an unbuffered 164 form, the penicillin may be less effective because of the low pH environment caused by the 165 aminoglycoside. From survey results it appears that quite a few practitioners (34%) mix the two 166 classes of drugs together either in the same syringe (20%) or the drugs are infused into the uterus 167 at the same time (14%). For maximum effectiveness, mixing these drugs within the uterus 168 should be discontinued and the drugs should be given either systemically or their administration 169 separated in time by an unknown number of hours if given by intrauterine infusion. It is also not 170 recommended to mix the two classes of drugs in lavage solutions. Interestingly, there are many 171 semen extenders that combine potassium penicillin and amikacin. This practice may diminish 172 the effectiveness of the antibiotics. Conversely, gentamicin has a high rate of inactivation when 173 mixed with certain beta-lactams, while amikacin is only slightly inactivated.25 174 When asked about which antifungal intrauterine drug they used prior to receiving culture 175 results, the majority of practitioners (32%) would not use an antifungal drug, but instead opted 176 for either a povidone-iodine solution lavage, lufenuron or, less commonly, a dilute vinegar 177 lavage. If an antifungal drug were used, then the most common responses included clotrimazole 178 (17%), nystatin (11%), miconazole (10%), fluconazole (8%) and amphotericin B (3%). No 179 answer was provided by 19% of the respondents. Only 53% of practitioners submitted fungal 180 cultures for sensitivity assay. Lack of antibiotic sensitivity patterns to determine the most 181 appropriate therapy may explain, in part, why fungal uterine infections are difficult to treat. The 182 reasons stated for not submitting fungal cultures for a sensitivity are: length of time to receive 183 418 results; had success with povidone-iodine lavage; all seem sensitive to amphotericin B; inability 184 to obtain fungal sensitivities from the laboratory; the relative infrequency with which fungal 185 infections were encountered precluded sensitivity testing; just treated Candida infection with 186 nystatin; or treating seems to work just fine. There are a number of laboratories that offer fungal 187 sensitivity patterns including the laboratory at Cornell University. There was also concern from 188 practitioners that in vitro sensitivity patterns may not correlate with in vivo effectiveness. It 189 would appear that within the group of polyene antifungal antibiotics, amphotericin B (96% 190 susceptibility of all fungal organisms) and nystatin (100% susceptibility) are good choices, 191 where as clotrimazole (80% susceptibility) or ketoconazole (81% susceptibility) are good 192 choices when using azole antifungal antibiotics. (personal communication, Marco Coutinho da 193 Silva, Cornell University) Polyene antibiotics are generally considered fungicidal, whereas azole 194 antibiotics are fungistatic, except at higher doses. Some practitioners try to avoid intrauterine 195 antifungal treatments with the concern that repeated intrauterine treatment may make the mare 196 more susceptible to re-infection or prolonged inflammation. An alternative would be oral 197 antifungal drugs which may be expensive. 198 Lufenuron is a chitin inhibitor which has been used in an extra-label manner for treatment 199 of fungal uterine infections.26 It should be noted that lufenuron affects the wall of growing fungi 200 and may not be appropriate for treatment of mature infections. A better approach may be to treat 201 with an antifungal antibiotic and then at the end of treatment, place lufenuron in the uterus to 202 prevent new growth. The effectiveness of lufenuron still remains in question.27,28 203 Uterine lavage with either iodine or vinegar is a component of therapy for many 204 veterinarians when treating fungal infections. Forty percent of veterinarians used a dilute iodine 205 solution for lavage (24% added iodine to saline, 16% added iodine to lactated Ringer’s solution). 206 419 The percent iodine in lavage solutions in the survey range from 0.02% (2 ml of 10% iodine per 207 liter) to 0.5% (50 ml of 10% iodine per liter). A 0.2% solution of iodine infused into the uterus 208 has been associated with endometrial inflammation and fibrosis.29 A 0.01% to 0.05% solution of 209 iodine maintains antimicrobial activity30 without causing inflammation and fibrosis.31 210 Practitioners should be cautious of the higher concentrations of iodine in intrauterine infusions. 211 Twenty-two percent of veterinarians used a dilute vinegar solution (15% of practitioners added 212 vinegar to saline, 7% added it to lactated Ringer’s solution). When using vinegar, saline would 213 be a more appropriate lavage solution, if the desire is to lavage with a lower pH solution. 214 Addition of 20 ml of white vinegar to 1000 ml of saline (2% v:v solution) will reduce the pH 215 from ≈5.5 to ≈3, whereas it has little effect on the pH of lactated Ringer’s solution. 216 Intrauterine antibiotics and lavage should be avoided within 4 hours of breeding12 so that 217 spermatozoa are not negatively affected by the drugs or the vehicles in which they are delivered. 218 After 4 hours post-insemination, spermatozoa are located in the oviduct and intrauterine 219 treatment at this time does not have a negative effect on fertility.32 Most practitioners who 220 participated in the survey appeared to be aware of this, with only 16% of them infusing 221 antibiotics within 4 hours post-insemination. Most practitioners (37%) withheld treatment for 222 more 4 hours post-breeding, because the next examination, and thus treatment of the mare, did 223 not occur until the day following insemination. 224 Systemic antibiotics 225 The decision to use systemic antibiotics either in combination with intrauterine infusion, 226 after intrauterine infusion or instead of intrauterine infusion of antibiotics may be due to personal 227 preference, a desire to prolong the treatment period, because the organism is not susceptible to 228 non-irritating drugs, or to avoid manual manipulation of the reproductive tract. Results of the 229 420 on-line survey indicated that systemic antibiotics are chosen when intrauterine treatments extend 230 beyond 3 to 5 days, when treating mares with metritis, when treating mares with contaminated 231 caudal reproductive tracts, when treating mares with anatomical defects of the caudal 232 reproductive tract or occasionally when treating mares with fungal infections. Respondents felt 233 that systemic antibiotics negate the need to invade the uterus, possibly avoiding the chances of 234 iatrogenically placed bacteria or fungi. The disadvantages of using systemic antibiotics are 235 increased costs and inconvenience from having to dose at the animal’s full body weight and 236 possibly the need to treat multiple times per day. A very small number of practitioners felt that it 237 was not good veterinary practice to place antibiotics directly into the uterus, since systemic 238 antibiotics work well, do not cause endometrial irritation, and do not lead to further 239 contamination. 240 Dosages for antibiotics commonly used systemically are presented in Table 2. 241 Trimethoprim sulfadiazine, ceftiofur, and a combination of penicillin and gentamicin were the 242 most common antibiotics administered by practitioners who participate in the survey. 243 Trimethoprim sulfamethoxazole (30 mg/kg, per os, q12h) was found to provide adequate 244 antibiotic concentrations in fetal tissues in mares with placentitis.33 In a separate study, ceftiofur 245 dosed at 2 mg/kg q12h intramuscularly, did not result in adequate endometrial tissue levels;34 246 however, it has been suggested as a potential treatment for mares with placentitis.35 Higher 247 dosage concentrations (recommended up to 4.4 mg/kg) and/or intravenous treatment could 248 perhaps result in adequate endometrial levels. In cattle, minimal inhibitory concentrations of 249 ceftiofur are achieved in endometrial tissue after subcutaneous administration.36 A study by 250 Murchie, et al., found that intravenous administration of penicillin G potassium and gentamicin 251 sulfate resulted in adequate allantoic fluid concentrations in pregnant pony mares.37 252 421 Enrofloxacin has also been used in mares with more resistant bacteria.20,38,39 Enrofloxacin 253 should not be used in pregnant mares due to its effects on developing cartilage.40 Doxycycline 254 has also been demonstrated to reach endometrial concentrations above the minimum inhibitory 255 concentration for Streptococcus equi subspecies zooepidemicus.41 256 Antifungal antibiotics may be administered systemically. Amphotericin B is fairly 257 caustic due to a low pH and needs to be given via nasogastric intubation or diluted and given 258 slowly intravenously. Oral fluconazole has been recommended for treatment of Candida spp. 259 while oral itraconazole has been suggested for treatment of Aspergillus spp. (personal 260 communication, Marco Coutinho da Silva, Cornell University). 261 Uterine Cytology 262 Uterine cytology was performed in conjunction with 67% of uterine cultures. This is a 263 relatively easy procedure to perform and interpret.42 Sixty-four percent of practitioners either 264 read their own (56%) or had someone in their practice (8%) read cytologies. By performing this 265 examination “in-house” results may be interpreted and therapy instituted without the delay of 266 sending the slides to an outside laboratory. Only 9% of practitioners, however, used Gram stain 267 to distinguish Gram negative from Gram positive bacteria in order to institute appropriate 268 antimicrobial therapy. 269 Treatments to augment antimicrobial therapy 270 Uterine lavage is recommended to remove uterine debris, bacteria and fungi and to 271 enhance uterine contractility. DMSO lavages may be useful to augment tissue penetration and to 272 disrupt microbial biofilms.43 Acetylcysteine and kerosene have also been suggested as possible 273 mucolytic agents. Biofilms are aggregates of bacteria and/or fungi encased in an adherent 274 polymeric matrix which may inhibit antibiotic penetration.44-46 Biofilms have been known to 275 422 form with Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebsiella 276 pneumonia, and Candida spp.47 277 Tris-EDTA has been demonstrated to act synergistically with antimicrobials by 278 increasing the membrane permeability of bacteria to these drugs.48 Uterine lavage with tris-279 EDTA, either alone or in combination with antibiotics, should be considered with resilient 280 infections or in cases with antibiotic-resistant organisms. 281 New intrauterine therapies 282 Intrauterine foam (Fatroximin®; Fatro, Bologna, Italy) containing the antibiotic 283 rifaximin, a synthetic derivative of rifamycin, has been developed for use in cattle and horses.49 284 It has a spectrum of activity that includes Gram negative, Gram positive and anaerobic bacteria. 285 The drug, in the foam vehicle, has a 72+ hour residual effect and expands to cover the entire 286 uterine lumen. A single treatment is recommended for treatment of endometritis or the product 287 may be administered for two consecutive days for treatment of vulvovaginitis. This drug is 288 currently available in Europe. 289 Conclusions. 290 Veterinarians should base antibiotic therapy on sensitivity tests. Consideration should be 291 given to antibiotic therapy alternatives such as proper breeding management, use of uterine 292 lavage and oxytocin or prostaglandin treatment. Biofilm formation should be appropriately 293 treated to enable antibiotics to access bacteria and fungi. With a plan, antibiotic usage can be 294 minimized and treatment success optimized. The main issues of concern identified from the on-295 line survey of veterinarians are: mixing beta-lactam and aminoglycoside antibiotics for 296 intrauterine infusion, intrauterine infusion of high concentrations of iodine solutions, use of 297 423 lactated Ringer’s solution with vinegar for uterine lavage, and treatment of mares less than 4 298 hours post-breeding with intrauterine antibiotics. 299 300 Table 1. Intrauterine antibiotic dosages. 301 302 Intrauterine antibiotics Antibacterial antibiotics Antibiotic Dosage Comments Major bacterial susceptibility Amikacin 1 to 2 grams Buffer with sodium bicarbonate or 150 to 200 ml solution Gram negative Ampicillin 1 to 3 grams Use soluble product, may be irritating when concentrated Gram positive and E.coli Ceftiofur sodium 1 gram Gram positive and Gram negative Chloramphenicol 2 to 3 grams Can be irritating Gram positive and Gram negative Gentamicin 1 to 3 grams Acidic – need to dilute and/or buffer Gram negative Neomycin 2 to 4 grams Gram negative Potassium penicillin 5 million Gram positive 424 international units Procaine penicillin 4.5 to 6 million international units Concern about residue left in uterus Gram positive Ticarcillin 3 to 6 grams Infuse with 150-200 ml solution Gram positive, Pseudomonas Ticarcillin with clavulanic acid 3 to 6 grams Beta-lactamase inhibitor, infuse with 150-200 ml solution Same as ticarcillin plus more Gram positive (Staph, Bacillus, Enterobacter) Antifungal antibiotics q24h for 7 days Drug Dosage Comment Amphotericin B 100-200 mg Polyene, dilute in >100 ml solution, mix well Clotrimazole 400 to 700 mg Azole, tablets usually crushed and mixed with solution Fluconazole 100 mg Azole, may need to adjust pH to avoid acidic nature Miconazole 500-700 mg Azole Nystatin 0.5 to 2.5 million international units Polyene, Dilute in sterile water, not saline to avoid precipitates, mix well 303 304 425 Table 2. Systemic antibiotic dosages. (IV-intravenous, IM-intramuscular, PO-per os, q-every, h-305 hour, IU-international units, kg-kilogram) 306 Systemic Antibiotics Antibacterial antibiotics Drug Dosage Route, Comment Amikacin 10 mg/kg q24h IV or IM Ampicillin 29 mg/kg q12-24h IV or IM Ceftiofur 2 to 4 mg/kg q12h IV or IM Doxycyline 10 mg/kg q12h PO Enrofloxacin 5.5 mg/kg q24h IV 7.5 mg/kg q24h Per os 4.0 mg/kg q12h Per os Gentamicin 6.6 mg/kg q24h IV or IM Metronidazole 15 to 25 mg/kg PO Oxytetracycline 6.6 mg/kg q12h IV, dilute and give slowly Potassium Penicillin 22,000 IU/kg q6h IV Procaine Penicillin 22,000 IU/kg q12h IM, only 10 ml per injection site Trimethoprim Sulfa 30 mg/kg q12h PO Antifungal antibiotics Drug Dosage Route Comments Amphotericin B 0.3 to 0.9 mg/kg q24-48h IV Polyene, dilute and give slowly Fluconazole 14 mg/kg loading, IV or per os Azole 426 then 5mg/kg q24h; alternatively, 2 grams q24h Itraconazole 5 mg/kg q12-24h IV or per os Azole, oral suspension more bioavailable than capsules Ketoconazole 20 mg/kg q12h in 0.2 N HCl Per nasogastric intubation Azole, irritant if given per os due to low pH – need to place into stomach 307 References 308 309 1. Tibary A, Fite DL: Reproductive tract infections. In: Sellon DC, Long MT, editors. 310 Equine infectious diseases. St. Louis: Saunders Elsevier; 2007. p. 84-96. 311 2. Perkins NR: Equine reproductive pharmacology. Vet Clin North Am Equine Pract 312 1999;15:687-704. 313 3. LeBlanc MM: The current status of antibiotic use in equine reproduction. Theriogenology 314 2009;21:156-167. 315 4. Lu KG, Morresey PR: Reproductive tract infections in horses. Vet Clin North Am Equine 316 Pract 2006;22:519-552. 317 5. Frontoso R, De Carlo E, Pasolini MP, et al: Retrospective study of bacterial isolates and 318 their antimicrobial susceptibilities in equine uteri during fertility problems. Res Vet Sci 319 2008;84:1-6. 320 427 6. Riddle WT, Leblanc MM, Pierce SW, et al. Relationships between pregnancy rates, 321 uterine cytology, and culture results in a Thoroughbred practice in central Kentucky. Proc 322 Annu Conv Am Assoc Equine Pract 2005; p. 198-201. 323 7. Brook D: Uterine culture in mares. Mod Vet Pract 1984;65:A3-8. 324 8. Nielsen JM: Endometritis in the mare: a diagnostic study comparing cultures from swab 325 and biopsy. Theriogenology 2005;64:510-518. 326 9. Ricketts SW, Mackintosh ME: Role of anaerobic bacteria in equine endometritis. J 327 Reprod Fertil 1987;35(Suppl):343-351. 328 10. Albihn A, Baverud V, Magnusson U: Uterine microbiology and antimicrobial 329 susceptibility in isolated bacteria from mares with fertility problems. Acta Vet Scand 330 2003;44:121-129. 331 11. Dascanio JJ: Treatment of fungal endometritis. In: Samper JC, Pycock J,McKinnon AO, 332 editors. Current therapy in equine reproduction. Philadelphia: Saunders, 2007. p. 116-333 120. 334 12. Blanchard TL, Varner DD, Schumacher J, et al: Endometritis. Manual of equine 335 reproduciton. 2nd ed. St. Louis: Mosby; 2003. p. 59-68. 336 13. Udekwu KI, Parrish N, Ankomah P, et al: Functional relationship between bacterial cell 337 density and the efficacy of antibiotics. J Antimicrob Chemother 2009;63:745-757. 338 14. Troedsson MH: Uterine clearance and resistance to persistent endometritis in the mare. 339 Theriogenology 1999;52:461-471. 340 15. Causey RC: Mucus and the mare: how little we know. Theriogenology 2007;68:386-394. 341 16. Easley J: External perineal conformation In: McKinnon AO,Voss JL, editors. Equine 342 reproduction. Hoboken: Wiley-Blackwell; 1993. p. 20-24. 343 428 17. Pycock J: Assessment of oxytocin and intrauterine antibiotics on intrauterine fluid and 344 pregnancy rates in mares. Proc Annu Conv Am Assoc Equine Pract 1994; p. 19-20. 345 18. Zent WW, Troedsson MH, Xue J: Postbreeding uterine fluid accumulation in a normal 346 population of Thoroughbred mares: a field study. Proc Annu Conv Am Assoc Equine 347 Pract 1998; p. 64-65. 348 19. Spensley MS, Baggot JD, Wilson WD, et al: Pharmacokinetics and endometrial tissue 349 concentrations of ticarcillin given to the horse by intravenous and intrauterine routes. Am 350 J Vet Res 1986;47:2587-2590. 351 20. Fumuso E, Checura C, Losinno L, et al: Endometrial tissue concentrations of 352 enrofloxacin after intrauterine administration to mares. Vet Res Commun 2002;26:371-353 380. 354 21. Bermudez L, Sifontes N, Navarro N, et al: Effects of intrauterine infusion of sodium 355 ceftiofur on the endometrium of mares. Proc Annu Conv Am Assoc Equine Pract 1995; 356 p. 261-263. 357 22. Van Camp SD, Papich MG, Whitacre MD: Administration of ticarcillin in combination 358 with clavulanic acid intravenously and intrauterinely to clinically normal oestrous mares. 359 J Vet Pharmacol Ther 2000;23:373-378. 360 23. Glew RH, Pavuk RA: Stability of gentamicin, tobramycin, and amikacin in combination 361 with four beta-lactam antibiotics. Antimicrob Agents Chemother 1983;24:474-477. 362 24. Holt HA, Broughall JM, McCarthy M, et al: Interactions between aminoglycoside 363 antibiotics and carbenicillin or ticarillin. Infection 1976;4:107-109. 364 429 25. Pickering LK, Gearhart P: Effect of time and concentration upon interaction between 365 gentamicin, tobramycin, Netilmicin, or amikacin and carbenicillin or ticarcillin. 366 Antimicrob Agents Chemother 1979;15:592-596. 367 26. Hess MB, Parker NA, Purswell BJ, et al: Use of lufenuron as a treatment for fungal 368 endometritis in four mares. J Am Vet Med Assoc 2002;221:266-267, 240. 369 27. Mancianti F, Dabizzi S, Nardoni S: A lufenuron pre-treatment may enhance the effects of 370 enilconazole or griseofulvin in feline dermatophytosis? J Feline Med Surg 2009;11:91-371 95. 372 28. Hector RF, Davidson AP, Johnson SM: Comparison of susceptibility of fungal isolates to 373 lufenuron and nikkomycin Z alone or in combination with itraconazole. Am J Vet Res 374 2005;66:1090-1093. 375 29. van Dyk E, Lange AL: [The detrimental effect of iodine as an intra-uterine instillation in 376 mares]. J S Afr Vet Assoc 1986;57:205-210. 377 30. Berkelman RL, Holland BW, Anderson RL: Increased bactericidal activity of dilute 378 preparations of povidone-iodine solutions. J Clin Microbiol 1982;15:635-639. 379 31. Brinsko SP, Varner DD, Blanchard TL, et al: The effect of postbreeding uterine lavage 380 on pregnancy rate in mares. Theriogenology 1990;33:465-475. 381 32. Brinsko SP, Varner DD, Blanchard TL: The effect of uterine lavage performed four hours 382 post insemination on pregnancy rate in mares. Theriogenology 1991;35:1111-1119. 383 33. Graczyk J, Macpherson ML, Pozor MA, et al: Treatment efficacy of trimethoprim 384 sulfamethoxazole and pentoxifylline in equine placentitis. Anim Repro Sci 2006;94:434-385 435. 386 430 34. Cervantes CC, Brown MP, Gronwall R, et al: Pharmacokinetics and concentrations of 387 ceftiofur sodium in body fluids and endometrium after repeated intramuscular injections 388 in mares. Am J Vet Res 1993;54:573-575. 389 35. Macpherson M: Treatment strategies for mares with placentitis. Theriogenology 390 2005;64:528-534. 391 36. Okker H, Schmitt EJ, Vos PL, et al: Pharmacokinetics of ceftiofur in plasma and uterine 392 secretions and tissues after subcutaneous postpartum administration in lactating dairy 393 cows. J Vet Pharmacol Ther 2002;25:33-38. 394 37. Murchie TA, Macpherson ML, LeBlanc MM, et al: Continuous monitoring of penicillin 395 G and gentamicin in allantoic fluid of pregnant pony mares by in vivo microdialysis. 396 Equine Vet J 2006;38:520-525. 397 38. Papich MG, Van Camp SD, Cole JA, et al: Pharmacokinetics and endometrial tissue 398 concentrations of enrofloxacin and the metabolite ciprofloxacin after i.v. administration 399 of enrofloxacin to mares. J Vet Pharmacol Ther 2002;25:343-350. 400 39. Giguere S, Sweeney RW, Belanger M: Pharmacokinetics of enrofloxacin in adult horses 401 and concentration of the drug in serum, body fluids, and endometrial tissues after 402 repeated intragastrically administered doses. Am J Vet Res 1996;57:1025-1030. 403 40. Egerbacher M, Edinger J, Tschulenk W: Effects of enrofloxacin and ciprofloxacin 404 hydrochloride on canine and equine chondrocytes in culture. Am J Vet Res 2001;62:704-405 708. 406 41. Bryant JE, Brown MP, Gronwall RR, et al: Study of intragastric administration of 407 doxycycline: pharmacokinetics including body fluid, endometrial and minimum 408 inhibitory concentrations. Equine Vet J 2000;32:233-238. 409 431 42. Dascanio JJ, Ley WB, Bowen JM: How to perform and interpret uterine cytology. Proc 410 Annu Conv Am Assoc Equine Pract 1997; p. 182-186. 411 43. Leblanc MM: When to refer an infertile mare to a theriogenologist. Theriogenology 412 2008;70:421-429. 413 44. Baillie GS, Douglas LJ: Matrix polymers of Candida biofilms and their possible role in 414 biofilm resistance to antifungal agents. J Antimicrob Chemother 2000;46:397-403. 415 45. Donlan RM, Costerton JW: Biofilms: survival mechanisms of clinically relevant 416 microorganisms. Clin Microbiol Rev 2002;15:167-193. 417 46. Gilbert P, Das J, Foley I: Biofilm susceptibility to antimicrobials. Adv Dent Res 418 1997;11:160-167. 419 47. Lynch AS, Robertson GT: Bacterial and fungal biofilm infections. Annu Rev Med 420 2008;59:415-428. 421 48. Farca AM, Nebbia P, Robino P, et al: Effects of the combination antibiotic--EDTA-Tris 422 in the treatment of chronic bovine endometritis caused by antimicrobial-resistant bacteria. 423 Pharmacol Res 1997;36:35-39. 424 49. Fatro-International. 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