section name header

Basics ⬇

Outline

BASICS

Definition!!navigator!!

  • Infectious/noninfectious endometrial inflammation
  • Major cause of mare infertility
  • Multifactorial disease classified in 1 of 4 groups:
    • Infectious (acute, chronic, or subclinical) endometritis
    • PMIE
    • Endometritis due to a sexually transmitted disease
    • Degenerative endometritis due to aging (angiosis, periglandular fibrosis)
  • May involve more than 1 group/origin

Pathophysiology!!navigator!!

Infectious Endometritis

  • Uterus repeatedly exposed to contamination at breeding, parturition, and gynecologic examinations
  • Uterine defense mechanisms to clear contamination, combination of:
    • Anatomic (physical) barriers
    • Cellular phagocytosis
    • Physical evacuation of uterine contents

Chronic and Subacute Infectious Endometritis

  • When treatments are unsuccessful in eliminating infectious agents or byproducts of inflammation
  • Reinfection caused by persisting anatomic/functional defects
  • Failure to identify the microorganisms
  • Excess of endometrial mucus production or accumulation:
    • Precludes antibiotics for reaching therapeutic concentrations
  • Bacterial biofilm:
    • Acts as a reservoir for microorganisms and increases resistance to antibiotics

PMIE

  • Increased parity in aged mares and incomplete cervical dilation in old maiden mares predisposes to intrauterine fluid accumulation
  • Breeding induces a normal, transient, endometritis
  • Byproducts of inflammation normally are removed by uterine contractions through an open estrual cervix. Following ovulation, the cervix closes; fluids within the uterine lumen are cleared by the lymphatics (<12 h post mating)
  • Fluid accumulation and lymphatic stasis increases if the uterus is suspended below the pelvic brim, uterine contractions are incomplete, or negligible cervical dilation during estrus

Low Pregnancy Rate

  • Direct—interference with embryo survival
  • Indirect—by premature luteolysis

Sexually Transmitted (Venereal) Endometritis!!navigator!!

  • Coitus or AI with infected semen
  • Most common bacteria are Pseudomonas aeruginosa, Klebsiella pneumonia, and Streptococcus zooepidemicus
    • All opportunistic organisms on the penile surface

Systems Affected!!navigator!!

Reproductive

Genetics!!navigator!!

N/A

Incidence/Prevalence!!navigator!!

Frequent

Signalment!!navigator!!

Infectious Endometritis

Predisposition to contamination is caused by an inherent or acquired anatomic defect of the vulva, vestibular sphincter, or cervix.

PMIE

  • Pluriparous mares—usually >12–14 years with pendulous uterus
  • Nulliparous mares—young or old, having incomplete cervical dilation during estrus

Signs!!navigator!!

Historical Findings

  • Infertility
  • Accumulation of uterine fluid (luminal) before and/or after breeding
  • Failure to conceive after repeated breeding to a stallion of known fertility
  • Early embryonic loss
  • Hyperemia of the cervix/vagina
  • Vaginal discharge

Physical Examination Findings

  • Can be inconclusive
  • Guarded swab, uterine brush or LVL to obtain samples for endometrial cytology and uterine culture
  • Endometrial biopsy is indicated only in specific cases

Infectious Endometritis

  • Abnormal vulvar conformation
  • TRP often not diagnostic
  • US usually reveals accumulation of echogenic (Streptococcus) or nonechogenic (Klebsiella) fluid in the uterine lumen
  • Hyperemia of vaginal and cervical mucosa; discharge may be observed at the cervix
  • Endometrial cytology and uterine culture reveal neutrophils; positive cytology when ≥1 PMNs/HPF (LVL) to ≥5 PMNs/HPF (swab, cup, brush)
  • Usually isolate a pure bacterial growth, single organism
  • Fungal endometritis usually follows excessive antibiotic uterine therapy
  • Fungal or bacterial endometritis may be overshadowing another bacteria not detected until first microorganism is eradicated

PMIE

  • External genitalia often normal
  • TRP, US, cytology/culture results may be inconclusive in the spring, prior to onset of the breeding season
  • Signs of persistent inflammation usually appear post breeding
  • May be hyperemia of vaginal and cervical mucosa due to irritation, rarely infection
  • Pendulous, edematous uterus in older mares
  • Presence of >2 cm (height determined by US) intrauterine fluid during estrus is diagnostic/predictive of PMIE
  • Postbreeding US reveals luminal fluid that persists for >12–24 h without treatment
  • Endometrial cytology reveals significant inflammation (≥1–5 PMNs/HPF)
  • Bacterial culture—usually negative

Causes!!navigator!!

See Pathophysiology.

Risk Factors!!navigator!!

See Pathophysiology.

Diagnosis ⬆ ⬇

Outline

DIAGNOSIS

Differential Diagnosis!!navigator!!

For Vaginal Discharge

  • Pneumovagina
  • Bacterial vaginitis secondary to pneumovagina
  • Treatment-induced vaginitis and/or necrosis
  • Necrotizing vaginitis secondary to excessive manipulation or inadequate lubrication, or contamination during the delivery of a necrotic fetus
  • Urine pooling
  • Varicosities in the region of the vaginovestibular sphincter
  • Lochia
  • Postpartum metritis
  • Pyometra
  • During pregnancy, may be a sign of placentitis
  • Ascending, infectious placentitis
  • Serosanguineous cervical discharge with a negative bacterial swab indicates premature placental separation

CBC/Biochemistry/Urinalysis!!navigator!!

N/A

Other Laboratory Tests!!navigator!!

Microbiology

Aerobes

  • Most common isolates—S. zooepidemicus and Escherichia coli
  • An endometrial sample of the surface (swab), contents (swab, LVL) or a biopsy is obtained
  • Contact (pressure with swab) the endometrial surface with a guarded swab for culture and identification of microorganism

Anaerobes

  • Bacteroides fragilis
  • May be recovered in some cases of postpartum metritis

Yeasts

  • Candida spp., Aspergillus spp.

Cytology

  • Sample is of endometrial cells and intraluminal content
  • Contact (pressure with swab) endometrial surface with the swab tip or cap (if using a Kalayjian swab); gently roll the sample onto a slide; stain with Diff-Quik
  • Presence of endometrial cells is necessary to be considered a valid/reliable cytology
  • Presence and number of PMNs is diagnostic and indicates the severity of uterine irritation
  • Microorganisms can be seen around cells or inside PMNs—branching and/or round structures are pathognomonic of fungal infection. Actinomyces cytology is also characterized by branching

Interpretation

  • Persistent, positive cytology without bacterial growth most often suggests a recurrent, noninfectious cause
  • Subclinical, chronic endometritis usually results from the inability to identify the microorganism due to focal location or difficult access deeper in a pendulous uterus
  • Positive culture with positive cytology—diagnostic for uterine infection
  • Positive culture with negative cytology—indicates contamination during uterine sampling in most cases
  • Negative cytology results in 30% of subsequently confirmed endometritis, due to inability to reach the PMNs in the pendulous areas of the uterus or E. coli or P. aeruginosa infections characterized by poor neutrophilic influx

Imaging!!navigator!!

US

  • Mares with DUC often have luminal fluid present before breeding and always retain fluid for 12–24 h post breeding
  • Persistent edema during and after ovulation—only occurs post breeding due to lymphatic stasis or endometritis

Other Diagnostic Procedures!!navigator!!

Low-Volume Uterine Lavage

  • Recommended for identification of chronic or subclinical endometritis
  • Twice as sensitive as endometrial swabbing and nearly as efficient (90%) as endometrial biopsy
  • In estrus or diestrus infuse the uterus with 60–150 mL of sterile saline or LRS, recover the effluent into a sterile container
  • The effluent is evaluated for cloudiness and amount of mucus. Both parameters are highly associated with the isolation of microorganism (70% of cases)
  • The sample settles for 30–60 min or is centrifuged at 400 g for 10 min. The pellet is sampled for culture and cytology
  • Can identify the presence of bacteria in cases with otherwise poor clinical presentation, e.g. weak influx of PMNs and decreased uterine fluid production
  • The cytologic evaluation includes the presence of PMNs (1 PMN/×40 field is indicative of inflammation), epithelial cells, bacteria, and debris to be considered an appropriate sample and to rule out false-positive cultures due to contamination

Endometrial Biopsy

  • Best method to determine the presence of endometritis when clinical and bacteriologic findings are inconclusive
  • Bacteriologic and cytologic results obtained by endometrial biopsy are considered the “gold standard” in the diagnosis of endometritis
  • Inflammatory cells (neutrophils) indicate active endometritis
  • Low numbers of lymphocytes and plasma cells (indicative of chronic endometritis) are not always associated with infertility
  • Lymphatic stasis is common in mares with a pendulous uterus and DUC

Endoscopy

  • When other modalities fail to define the cause of infertility
  • Better method to visualize intrauterine adhesions affecting uterine drainage, luminal tumors, or uterine abscess (rare)

Pathologic Findings!!navigator!!

Endometritis

  • Cannot predict a mare's endometrial biopsy category, ranges from IIA to III (rarely)
  • Category relates to the length of sexual rest, conformational abnormalities, and age
  • Histopathology associated with endometritis—mild, diffuse lymphocytic or neutrophilic infiltration; focally moderate fibrosis (1–4 nests); lymphangiectasia, presence of bacteria (if infectious), excess mucus if recurrent irritation

PMIE

  • Biopsy score at the beginning of the breeding season is not diagnostic
  • Category may be IIA or IIB, with mild inflammation and moderate fibrosis
  • After breeding, interstitial edema; lymphatic stasis; diffuse/acute/or subacute inflammation (PMNs) usually develop
  • Serial sampling may be useful

Treatment ⬆ ⬇

Outline

TREATMENT

Appropriate Health Care!!navigator!!

Minimize contamination during breeding:

  • Wash mare's perineum and stallion's penis with clean water; dry the stallion's penis prior to mating or semen collection for AI
  • Limit to 1 breeding (live cover or AI) per estrus
  • Breed as close to ovulation as possible
  • In mares predisposed to infectious endometritis, immediately prior to natural breeding (live cover) infuse semen extender (60–120 mL) with nonspermicidal antibiotic (antibiotic concentration compatible with sperm viability); minimum contamination technique

Nursing Care!!navigator!!

N/A

Activity!!navigator!!

N/A

Diet!!navigator!!

N/A

Client Education!!navigator!!

N/A

Surgical Considerations!!navigator!!

  • Consider feasibility of surgical correction of predisposing causes before treating a uterine infection—Caslick's vulvoplasty (pneumovagina); vaginoplasty; urethral extension (urine pooling); repair of cervical tears
  • Rectovaginal fistula and extensive cervical tears (foaling trauma—prudent to wait for results of endometrial biopsy before surgery if the broodmare has been barren for >1 year). Chronic endometritis may have seriously worsened the mare's biopsy category

Medications ⬆ ⬇

Outline

MEDICATIONS

Drug(s) of Choice!!navigator!!

General Principles

  • Administer treatments during estrus, although this is controversial
  • For infectious endometritis, organism is eliminated chemically (local antibiotics, antiseptics), and mechanically (uterine lavage, ecbolic drugs)
  • Systemic treatment when 2 organisms with different sensitivity are isolated—local antibiotic for one microorganism and systemic for the other. Also, when access to the mare is limited, e.g. unsafe or unsanitary conditions, or when avoiding further uterine contamination
  • Subclinical and chronic endometritis—unsuccessful in eliminating microorganism due to reinfection; failure to isolate microorganism due to method used; excessive mucus production, bacterial biofilm
  • New methods for treatment include mucolytic drugs, buffered chelating agents, solvents, CSA and immune modulators in addition to uterine lavage, oxytocin, and the antibiotic of choice
  • Uterine lavage is recommended for DUC and to evacuate debris from the uterus before antibiotic instillation, if necessary:
    • Uterine lavage with LRS (without oxytocin) can be performed 1 h prior to insemination if there is intrauterine fluid, e.g. rebreeding or multiple inseminations in a 24 h period
    • If oxytocin is used during/after the lavage, it is advisable to wait 4 h before inseminating the mare

Infectious Endometritis

Acute Endometritis

  • Uterine lavage without oxytocin (daily or when intrauterine fluid ≥2 cm) followed by intrauterine infusion of chosen antibiotics for 3–7 days. Oxytocin is administered 8–12 h later to stimulate uterine evacuation without interfering with the antibiotic's action
  • Antibiotics based on culture and sensitivity; should be diluted in 60–120 mL of sterile saline (maximum volume infused)

Chronic Inflammation

Do not breed mare until 45–60 days after treatment.

Chronic Infectious Endometritis

Surgical correction of defective anatomic barriers before intrauterine treatment.

Subclinical Endometritis

Positive or negative cytology, no bacteria identified but clinical signs and subfertility/infertility present:

  • Uterine lavage if intrauterine fluid is present, the antibiotic(s) of choice should be infused by diluting in LRS alone or in combination with mucolytic drugs if excessive mucus; buffer chelators to increase bacterial permeability; and/or nonantibiotics, anti-infectious agents (CSA)
  • If history warrants, consider postbreeding treatment

Yeast Infection

  • Correct anatomic defects; culture and treat uterus and reservoirs of infection, e.g. vagina and clitoral fossa
  • Uterine lavage since fluid is frequently present. The antifungal of choice (nystatin, clotrimazole, etc.) should be infused by diluting in LRS alone or in combination with buffer chelators (Tris-EDTA, Tricide®) to increase microorganism permeability to the drug
  • Alternatively, uterine lavage with diluted 0.01–0.05% povidone–iodine solution (to the approximate color of light iced tea), acetic acid/vinegar (2%), or peroxide (3% v/v = 30 mL H2O2 in 1 L of 0.9% saline) for 7–10 days
  • Repeat culture and cytology in the following estrus (uterus, vagina, and clitoral fossa)

PMIE

  • Manual cervical dilation before breeding with systemic (cloprostenol) or local application (misoprostol) may help intrauterine semen deposition and uterine clearance
  • Foaling, at least once, is highly recommended to improve cervical relaxation and drainage in old maiden mares
  • Promote uterine clearance by lavage and ecbolic drugs (oxytocin, carbetocin, cloprostenol)
  • Control intrauterine fluid production and excessive edema by modulating inflammation and immune response (glucocorticoids) of mares with history of acute and persistent inflammation post breeding
  • Mare with no history or characteristics of DUC:
    • Begin evaluation and treatment, if necessary, 12 h post breeding to let the normal mechanisms of clearance occur
  • If the mare has been diagnosed with PMIE:
    • 4–8 h post breeding promote uterine clearance by uterine lavage with LRS or saline, followed by the administration of an ecbolic drug
    • 4 h interval ensures spermatozoa are in the oviduct, 8 h interval that bacteria have not yet adhered or multiplied in the uterus
  • Oxytocin during or immediately after lavage stimulates strong uterine contractions, clears the remaining uterine contents, and promotes lymphatic drainage
  • Administer oxytocin every 3–4 h in refractory cases, e.g. older maiden mares
  • PGF2α (Lutalyse®) and analogs (cloprostenol):
    • Sustains smoother uterine contractions longer than oxytocin (4–5 h vs. 45–60 min)
    • Reduce persistent uterine edema by stimulating lymphatic drainage
  • Administration of glucocorticoids at the time of breeding (before, during, and/or after) increases pregnancy rate

US

  • 4–8 h post AI or breeding (not ovulation)—check for uterine fluid:
    • If >2 cm free fluid, lavage uterus with 1–3 L of sterile saline or LRS
    • Administer oxytocin during or after lavage
    • If only a small amount of free fluid, administer only oxytocin
  • If possible, 12 h after breeding—use cloprostenol if history includes dilated uterine lymphatics and poor drainage. Use dexamethasone if excessive edema
  • 24 h after breeding—if mare has free intraluminal fluid, lavage and oxytocin
    • If free fluid and persistent edema in the walls—lavage the uterus/oxytocin and add a regimen of IV/IM oxytocin alternating with IM cloprostenol every 4–6 h
    • If only edema is present, cloprostenol every 4–12 h, up to 36 h post ovulation. Dexamethasone 20 mg IV once daily is also a good option before and after 36 h
  • 48 h post breeding—if the mare has not ovulated, rebreed; oxytocin/cloprostenol sequence begins anew. Prebreeding uterine lavage may be indicated
  • Treatment should continue, if necessary, no more than 3–4 days post ovulation:
    • Embryo enters the uterus day 5 + 20 h; allows treatment-induced uterine inflammatory response to subside

Drugs and Fluids

Intrauterine Antibiotics Most Frequently Used

  • Amikacin (0.5–2 g)—Gram negative; Pseudomonas and Klebsiella spp. An intrauterine infusion of Tris-EDTA increases the permeability of the Pseudomonas capsule to the antibiotic
  • Ampicillin (1–3 g)—Gram positive; streptococci
  • Carbenicillin (2–6 g)—broad spectrum; persistent Pseudomonas spp.
  • Gentamicin (0.5–2 g)—primarily Gram negative; streptococci
  • K-penicillin (5 × 106 U)—Gram positive; streptococci
  • Ticarcillin/Timentin® (3–6 g)—broad spectrum
  • Ceftiofur sodium/Naxcel® (1 g)—broad spectrum
  • Aminoglycosides must be buffered before infusion. Mix the antibiotic with an equal volume of sodium bicarbonate, then dilute in sterile saline

Systemic Antibiotics

  • Ceftiofur in crystalline form—Excede®; very effective at treating endometritis due to S. zooepidemicus. Full therapy—2 doses (6.6 mg/kg) IM 4 days apart
  • Trimethoprim–sulfamethoxazole
  • Trimethoprim-sulfadiazine Equisul® (24 mg/Kg BID) provides drug concentrations above the MIC90 for at least 98% of the dosing interval
  • K-penicillin
  • Procaine penicillin G
  • Gentamicin
  • Amikacin
  • Ampicillin

Antimycotics

  • Nystatin (0.5–2.5 × 106 U)—Candida spp.
  • Clotrimazole (500–700 mg)—Candida spp.
  • Amphotericin B (100–200 mg)—Aspergillus, Candida, and Mucor spp.; tablets must be crushed and well suspended in 60–120 mL of sterile saline for intrauterine infusion

Others

New Methods

  • Mucolytic agents (NAC), buffered chelating agents (Tris-EDTA), and solvents (DMSO) have been added to the uterine lavage treatment to dissolve exudates, mucus, or bacterial biofilm
  • NAC—infuse a 3.3% solution of NAC (30 mL of a 20% solution in 150 mL of saline or LRS) on day 1 of the treatment followed by uterine lavage 24 h later. In vitro studies showed that mixing NAC with antibiotics in the same syringe, reduces the antibiotic efficacy. The removal of debris, secretions, exudate, mucus and the potential disruption of the bacterial biofilm may:
    • Expose otherwise inaccessible microorganisms, so culture of lavage effluent is recommended
    • Increase the level of antibiotic locally available
  • Buffered chelating solutions or agents—Tris-EDTA in cases of failure of antimicrobial therapy in infectious endometritis due to the presence of biofilm produced by Gram-negative bacteria or fungi that confer microbial resistance
    • Biofilm-producing pathogens are P. aeruginosa, Staphylococcus epidermis, E. coli, Enterobacter cloacae, and some fungi
    • The initial volume of infusion should be sufficient to fill the uterine lumen (250–1000 mL, based on horn size) so that microorganisms are reached within minutes. The treatment-induced accumulation of bacterial/cellular debris should be cleared from the uterus by uterine lavage within 24 h
    • The recommended protocol consists of uterine lavage (LRS) followed by uterine infusion with 250–1000 mL of the buffered chelating solution. Advisable to repeat lavage 12–24 h later to remove cellular debris and dead bacteria
    • Mix the appropriate antibiotic with 30–40 ml of buffered chelating solution to a final volume of 60–80 ml in the days following the first treatment or from the first day (if bacteria have already been identified). This treatment can be repeated on subsequent days of the same estrus
  • DMSO 30% (33 mL of DMSO at 90% in 64 mL of saline solution)
  • CSA (Ceragyn®)—nonantibiotic, broad-spectrum antibacterial, antifungal, and antiviral agent. Good option when antibiotic resistance is present
    • Used for uterine infusion (60 mL vial) or for uterine lavage (mix 60 mL vial with LRS and flush the uterus 4 h before or 6–48 h after breeding)

Uterotonic/Ecbolic Drugs

  • Oxytocin (10 IU or 20 IU IV or IM)
  • Carbetocin (175 µg IV or IM), synthetic analog of oxytocin; its half-life is 2.5 times longer than oxytocin. Unavailable in the USA
    • Recommended for mares that accumulate intrauterine fluid before and after breeding and respond poorly to conventional dose and frequency of oxytocin
    • Useful when access to the mare is limited
  • Cloprostenol (250–500 µg IM/500 kg mare, Estrumate®), a synthetic analog of PGF2α which has uterotonic properties
    • Used to expel intrauterine fluid through a poorly dilated or inefficient cervix, i.e. older maiden mares, and to reduce edema due to dilated lymphatics by sustained uterine contractions of smooth muscle
    • Its effect lasts longer than oxytocin (4 h vs. 45–60 min) with fewer adverse effects

Cervical Dilation

  • Synthetic prostaglandin E1 (misoprostol 200 µg/3 mL ointment) is used for cervical relaxation
    • Applied onto cervical mucosa 2–4 h before breeding; achieves cervical relaxation for 8 h, favors not only breeding but also drainage post breeding
    • Buscopan® solution, a smooth muscle relaxant (3 ml mixed with sterile lube) is empirically used for cervical relaxation

Immunomodulators

  • Glucocorticoids and immunomodulators—administered around the time of breeding, in combination with traditional postbreeding treatments; increase pregnancy rates
    • Prednisolone acetate (0.1 mg/kg every 12 h) beginning 48 h before breeding and continuing until ovulation
    • Single dose of dexamethasone (50 mg IV) administered 1 h after breeding
    • Common practice—dexamethasone (20 mg every 24 h) beginning 24 h before breeding and continuing until ovulation or up to 24–48 h after. Clinically may be some benefit to continue its use up to 72 h if edema persists or a small amount of fluid remains (refractory to oxytocin administration)
  • Cell-mediated immunomodulators—mycobacterial cell wall extract, e.g. Settle® and EqStim®, believed to induce and increase cell-mediated immunity
    • Settle is effective to clear S. zooepidemicus-induced endometritis
    • Mares with persistent endometritis treated with EqStim had higher pregnancy rates than mares treated with conventional treatment

Contraindications!!navigator!!

  • Do not administer prostaglandin or its analogs >36 h post ovulation; affects progesterone production by the CL; may result in EED
  • Intrauterine infusion of enrofloxacin (Baytril®) is contraindicated; not labeled for horses; highly irritating for endometrium
  • Glucocorticoids are only recommended in mares with a negative bacterial culture
  • Do not mix NAC and antibiotics in the same syringe since reduces antibiotic activity

Precautions!!navigator!!

Adverse reactions may occur with natural or synthetic prostaglandin—transient sweating, ataxia, increased gastrointestinal motility.

Follow-up ⬆ ⬇

Outline

FOLLOW-UP

Patient Monitoring!!navigator!!

  • Complete the gynecologic evaluation with special attention to uterine culture/cytology on day 1 or 2 of the estrus after treatment
  • If no conception after several attempts, repeat the complete evaluation

Possible Complications!!navigator!!

  • Pyometra
  • Secondary bacterial/yeast overgrowth due to excessive use of antibiotics
  • Uterine adhesions

Miscellaneous ⬆ ⬇

Outline

MISCELLANEOUS

Age-Related Factors!!navigator!!

See Risk Factors.

Abbreviations!!navigator!!

  • AI = artificial insemination
  • CL = corpus luteum
  • CSA = cationic steroid antimicrobial
  • DMSO = dimethylsulfoxide
  • DUC = delayed uterine clearance
  • EED = early embryonic death
  • HPF = high-powered field (microscopy)
  • LRS = lactated Ringer's solution
  • LVL = low-volume uterine lavage
  • NAC = N-acetylcysteine
  • PGF2α = prostaglandin F2α
  • PMIE = persistent mating-induced endometritis
  • PMN = polymorphonuclear cell
  • TRP = transrectal palpation
  • US = ultrasonography, ultrasound

Suggested Reading ⬆ ⬇

Asbury AC, Lyle SK. Infectious causes of infertility. In: McKinnon AO, Voss JL, eds. Equine Reproduction. Philadelphia, PA: Lea & Febiger, 1993:381–391.

Blanchard TL, Varner DD, Schumacher J. Uterine defense mechanisms in the mare. In: Manual of Equine Reproduction. St. Louis, MO: Mosby, 1998:47–58.

Brinsko S, Rigby SL, Varner DD, Blanchard TL. A practical method for recognizing mares susceptible to post-breeding endometritis. Proc Am Assoc Equine Pract 2003;49:363–365.

Bucca S, Carli A, Buckley T, et al. The use of dexamethasone administered to mares at breeding time in the modulation of persistent mating induced endometritis. Theriogenology2008;70:1093–1100.

Hess MB, Parker NA, Purswell BJ, Dascanio JD. Use of Lufenuron as a treatment for fungal endometritis in four mares. J Am Vet Med Assoc 2002;221:266–267.

LeBlanc MM. How to perform and interpret findings from a low volume uterine flush. Proc Am Assoc Equine Pract 2011;57:32–36.

Lyle SK. Incorporating non-antibiotic anti-infective agents into the treatment of equine endometritis. Clin Theriogenol 2012;4(3):386–390.

Nielsen JM, Troedsson MHT, Pedersen MR, et al. Diagnosis of endometritis in the mare based on bacteriological and cytological examinations of the endometrium: comparison of results obtained by swabs and biopsies. J Equine Vet Sci 2010;30:27–30.

Vanderwall DK, Woods GL. Effect on fertility of uterine lavage performed immediately prior to insemination in mares. J Am Vet Med Assoc 2003;222:1108–1110.

Author(s) ⬆

Author: Maria E. Cadario

Consulting Editor: Carla L. Carleton