INFLAMMATION, INFECTION, OR BOTH? ROOT CAUSES OF ENDOMETRITIS
inflammatory mediators. The dose of firocoxib used in this studywas 0.2mg/kg as compared to themore com- monly used dose of 0.1mg/kg, once daily (after a single loading dose of 0.3mg/kg).28 Bacterial cell wall extracts have been investi-
gated regarding their effects on uterine immune system and enhancement of pregnancy rates. While the majority of work is focused on clearance and treatment of infectious endometritis, a study in 2012 evaluatedtheimmuneresponsetosperma- tozoa. Mares were treated with 1.5mg Settle IVa 24hours prior to insemination. Overall, a downreg- ulation of IL-1 messenger RNA was found in this population of susceptible mares 6hours after AI.22 Large-scale clinical trials showing alterations in pregnancy rates using bacterial cell wall extracts are limited in the treatment ofPMIE.
Mucolytics and Chemical Curettage
Not uncommonly, the lavage effluent from mares with PMIE contains excessive quantities of mucus.29 Chronic uterine inflammation often results in produc- tion of exuberant production ofmucus,whichmanifests as a thick mucus layer overlying the endometrium. Mucolytic agents such as N-acetylcysteine, or other agents focusing on stoppingmucous production, includ- ing dimethyl sulfoxide or kerosene, can be used with beneficial effects in some mares. N-acetylcysteine dis- rupts disulfide bonds in mucus, making it less viscous. Infusion of 3.3%N-acetylcysteine (30mL of a 20% solu- tion diluted in 150mL saline solution) has been associ- ated with an increase in pregnancy rates inmares that have excessivemucus accumulation.30 Infusion of a 30%solution of dimethyl sulfoxide into
the uterus results in improvement of biopsy grade, and treated mares tend to have an increased preg- nancy rate.31 Although intrauterine infusion of kero- sene is associated with a severe endometritis and necrosis of the luminal epithelium, 50% of treated mares with a category II or III biopsy score became pregnant on the subsequent cycle and carried foals to term.32 It is thought that the severe inflammation and necrosis results in removal of mucus and exudate from the uterine epithelium.32 Kerosene treatment typically consists of infusion of 50 to 500 mL of kero- sene undiluted into the uterus. Typically, lower vol- umes are used during diestrus and larger volumes during estrus to account for an open vs closed cervix. Uterine lavage and ecbolics are used 12 to 18hours later to remove residual kerosene and debris from the uterus.
3. Platelet-Rich Plasma
Platelet-rich plasma (PRP) is a filtrate of whole blood plasma with a high concentration of platelets. PRP contains various growth factors and cytokines that act in an anti-inflammatory manner throughout the body. This therapy has become common to reduce PMIE inflammation and fluid accumulation post- breeding.33–38 Common time points to use PRP are
48 and 24hours prior to breeding and 6 and 24hours postbreeding.
4. Summary
Multiple treatments have been utilized to treat PMIE in the horse. The clinician is faced with the challenge of how to select these treatment options in clinical practice. Overall, as the severity of PMIE increases, the treatments required to manage fluid retention and uterine inflammation are increased. The best approach to treating mares with PMIE is to obtain a thorough history, perform serial examinations, and optimize the treatment regimen for each, individual mare.
Acknowledgments
Declaration of Ethics The Author has adhered to the Principles of VeterinaryMedical Ethics of the AVMA.
Conflict of Interest The Author has no conflicts of interest.
References and Footnote
1. Traub-Dargatz JL, Salman MD, Voss JL. Medical problems of adult horses, as ranked by equine practitioners. J Am Vet Med Assoc 1991;198:1745–1747.
2. Troedsson MH, Loset K, Alghamdi AM, et al. Interaction between equine semen and the endometrium: The inflam- matory response to semen. Anim Reprod Sci 2001;68:273– 278.
4. Causey RC. Making sense of equine uterine infections: The many faces of physical clearance. Vet J 2006;172:405–421.
5. Samper J. Uterine edema in the mare. In: Samper J, ed. Equine Breeding Management and Artificial Insemination. St Louis, MO: Elsevier; 2009;133–138.
6. Betteridge K, Eaglesome M, Mitchell D, et al. Development of horse embryos up to twenty two days after ovulation: Observations on fresh specimens. J Anat 1982;135:191–209.
7. Neely DP, Kindahl H, Stabenfeldt GH, et al. Prostaglandin release patterns in the mare: Physiological, pathophysio- logical, and therapeutic responses. J Reprod Fert Supp 1979;27:181–189.
8. Scoggin CF. Not just a number: Effect of age on fertility, pregnancy and offspring vigour in Thoroughbred brood- mares. Reprod Fertil Dev 2015;27:872–879.
9. Woodward EM, Christoffersen M, Campos J, et al. Susceptibility to persistent breeding-induced endometri- tis in the mare: Relationship to endometrial biopsy score and age, and variations between seasons. Theriogenology 2012;78:495–501.
10. Canisso IF, Segabinazzi LGTM, Fedorka CE. Persistent breeding-induced endometritis in mares—a multifaceted challenge: From clinical aspects to immunopathogenesis and pathobiology. Int J Mol Sci 2020;21:1432.
11. Cadario ME, Thatcher WW, Klapstein E, et al. Dynamics of prostaglandin secretion, intrauterine fluid and uterine clear- ance in reproductively normal mares and mares with delayed uterine clearance. Theriogenology 1999;52:1181–1192.
12. Madill S, Troedsson MHT, Santschi EM, et al. Dose response effect of intramuscular oxytocin treatment on
AAEP PROCEEDINGS / Vol. 68 / 2022 39
3. Allen WE, Pycock JF. Cyclical accumulation of uterine fluid in mares with lowered resistance to endometritis. Vet Rec 1988;122:489–490.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191 |
Page 192 |
Page 193 |
Page 194 |
Page 195 |
Page 196 |
Page 197 |
Page 198 |
Page 199 |
Page 200 |
Page 201 |
Page 202 |
Page 203 |
Page 204 |
Page 205 |
Page 206 |
Page 207 |
Page 208 |
Page 209 |
Page 210 |
Page 211 |
Page 212 |
Page 213 |
Page 214 |
Page 215 |
Page 216 |
Page 217 |
Page 218 |
Page 219 |
Page 220 |
Page 221 |
Page 222 |
Page 223 |
Page 224 |
Page 225 |
Page 226 |
Page 227 |
Page 228 |
Page 229 |
Page 230 |
Page 231 |
Page 232 |
Page 233 |
Page 234 |
Page 235 |
Page 236 |
Page 237 |
Page 238 |
Page 239 |
Page 240 |
Page 241 |
Page 242 |
Page 243 |
Page 244 |
Page 245 |
Page 246 |
Page 247 |
Page 248 |
Page 249 |
Page 250 |
Page 251 |
Page 252 |
Page 253 |
Page 254 |
Page 255 |
Page 256 |
Page 257 |
Page 258 |
Page 259 |
Page 260 |
Page 261 |
Page 262 |
Page 263 |
Page 264 |
Page 265 |
Page 266 |
Page 267 |
Page 268 |
Page 269 |
Page 270 |
Page 271 |
Page 272 |
Page 273 |
Page 274 |
Page 275 |
Page 276 |
Page 277 |
Page 278 |
Page 279 |
Page 280 |
Page 281 |
Page 282 |
Page 283 |
Page 284 |
Page 285 |
Page 286 |
Page 287 |
Page 288 |
Page 289 |
Page 290 |
Page 291 |
Page 292 |
Page 293 |
Page 294 |
Page 295 |
Page 296 |
Page 297 |
Page 298 |
Page 299 |
Page 300 |
Page 301 |
Page 302 |
Page 303 |
Page 304 |
Page 305 |
Page 306 |
Page 307 |
Page 308 |
Page 309 |
Page 310 |
Page 311 |
Page 312 |
Page 313 |
Page 314 |
Page 315 |
Page 316 |
Page 317 |
Page 318 |
Page 319 |
Page 320 |
Page 321 |
Page 322 |
Page 323 |
Page 324 |
Page 325 |
Page 326 |
Page 327 |
Page 328 |
Page 329 |
Page 330 |
Page 331 |
Page 332 |
Page 333 |
Page 334 |
Page 335 |
Page 336 |
Page 337 |
Page 338 |
Page 339 |
Page 340 |
Page 341 |
Page 342 |
Page 343 |
Page 344 |
Page 345 |
Page 346 |
Page 347 |
Page 348 |
Page 349 |
Page 350 |
Page 351 |
Page 352 |
Page 353 |
Page 354 |
Page 355 |
Page 356 |
Page 357 |
Page 358 |
Page 359 |
Page 360 |
Page 361 |
Page 362 |
Page 363 |
Page 364 |
Page 365 |
Page 366 |
Page 367 |
Page 368 |
Page 369 |
Page 370 |
Page 371 |
Page 372 |
Page 373 |
Page 374 |
Page 375 |
Page 376 |
Page 377 |
Page 378 |
Page 379 |
Page 380 |
Page 381 |
Page 382 |
Page 383 |
Page 384 |
Page 385 |
Page 386 |
Page 387 |
Page 388 |
Page 389 |
Page 390 |
Page 391 |
Page 392 |
Page 393 |
Page 394 |
Page 395 |
Page 396 |
Page 397 |
Page 398 |
Page 399 |
Page 400 |
Page 401 |
Page 402 |
Page 403 |
Page 404 |
Page 405 |
Page 406 |
Page 407 |
Page 408 |
Page 409 |
Page 410 |
Page 411 |
Page 412 |
Page 413 |
Page 414 |
Page 415 |
Page 416 |
Page 417 |
Page 418 |
Page 419 |
Page 420 |
Page 421 |
Page 422 |
Page 423 |
Page 424 |
Page 425 |
Page 426 |
Page 427 |
Page 428 |
Page 429 |
Page 430 |
Page 431 |
Page 432 |
Page 433 |
Page 434 |
Page 435 |
Page 436 |
Page 437 |
Page 438 |
Page 439 |
Page 440 |
Page 441 |
Page 442 |
Page 443 |
Page 444 |
Page 445 |
Page 446 |
Page 447 |
Page 448 |
Page 449 |
Page 450 |
Page 451 |
Page 452 |
Page 453 |
Page 454 |
Page 455 |
Page 456 |
Page 457 |
Page 458 |
Page 459 |
Page 460 |
Page 461 |
Page 462 |
Page 463 |
Page 464 |
Page 465 |
Page 466 |
Page 467 |
Page 468 |
Page 469 |
Page 470 |
Page 471 |
Page 472 |
Page 473 |
Page 474 |
Page 475 |
Page 476 |
Page 477 |
Page 478 |
Page 479 |
Page 480 |
Page 481 |
Page 482 |
Page 483 |
Page 484 |
Page 485 |
Page 486 |
Page 487 |
Page 488 |
Page 489 |
Page 490 |
Page 491 |
Page 492 |
Page 493 |
Page 494 |
Page 495 |
Page 496 |
Page 497 |
Page 498 |
Page 499 |
Page 500 |
Page 501 |
Page 502 |
Page 503 |
Page 504 |
Page 505 |
Page 506 |
Page 507 |
Page 508 |
Page 509 |
Page 510 |
Page 511 |
Page 512
