Volume 48 | Issue 1 Article 4

1986 in the Mare Mary A. Ebert Iowa State University

Richard L. Riese Iowa State University

Follow this and additional works at: https://lib.dr.iastate.edu/iowastate_veterinarian Part of the Female Urogenital Diseases and Pregnancy Complications Commons, and the Large or Food Animal and Equine Medicine Commons

Recommended Citation Ebert, Mary A. and Riese, Richard L. (1986) "Infertility in the Mare," Iowa State University Veterinarian: Vol. 48 : Iss. 1 , Article 4. Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol48/iss1/4

This Article is brought to you for free and open access by the Journals at Iowa State University Digital Repository. It has been accepted for inclusion in Iowa State University Veterinarian by an authorized editor of Iowa State University Digital Repository. For more information, please contact [email protected]. Infertility in the Mare

Mary A. Ebert, BS, DVM,* Richard L. Riese, DVM, DACT* *

INTRODUCTION uterine defense system, in addition to the leu­ Infertility in the mare results in a signifi­ kocyte function, includes ovarian hormones, cant loss of dollars in the horse industry every non-cellular bactericidal factors, and immune year. It is defined as the absence of the ability responses.28 Local synthesis of antibodies, to conceive. 13 There are many causes of infer­ mainly IgA, occurs in the secrectory epithe­ tility that are recognized, including infectious, lium, and a transport mechanism moves the inflammatory, a faulty uterine immune sys­ polymeric Ig across into the , , tem, trauma and scarring, hormonal, twin­ and .32 Six of the ten known equine ning, neoplasia, and congenital abnormali­ immunoglobulins have been found in uterine ties. flushings. Some investigators report that these are in higher concentrations in fertile mares, CAUSES OF INFERTILITY while others dispute these findings. 25 ,27 When Infectious is probably the bacteria penetrate the mucosal barrier, the number one cause of infertility in the mare, higher protein level stimulates the defense 6 25 and contributes significantly to fetal death. ,9 mechanism: ,27 Mares with a decreased re­ A large variety of organisms have been sistance to infection undergo rapid comple­ cultured in both the mare and stallion, but ment inactivation, possibly of enzymatic ori­ much disagreement exists as to the clinical gin. 1 A failure of the uterine defense significance of these positive cultures. 6 A large mechanism leads to a prolonged inflammation number of bacteria normally enter the uterus and an endometritis.3 at breeding when the cervix is relaxed.3,25 If Ovarian hormones greatly influence the in­ these are not eliminated by about five days flammatory and immune responses of the post-ovulation when the embryo descends to uterus. These defense systems have the the uterus, infertility may result.3 Mares can greatest ability at estrus when the vascular conceive while infected, but many will abort, system is the most permeable.32 28 resorb, or produce infected foals. 9 Pyometra inhibits the immune response. Many mares occasionally occurs, but does not show sys­ become anestrus after embryonic loss, delay­ temic manifestations as in the canine.20 ing the next estrus for a significant period of The mare has a highly efficient defense time.23 Infrequent, irregular estrus due to em­ mechanism that clears the uterus of bacterial bryonic loss and decreased ovarian activity is contamination, so inflammation is a normal common in the least productive mares. 21 Em­ response in fertile mares.3 This mechanism bryonic losses occur because of nutritional de­ involves phagocytosis by neutrophils, primar­ ficiencies, endometrial disease, stress, twin­ ily, which respond to a massive invasion of the ning' paternal influences, chromosomal uterine lumen by debris and bacteria within 6 aberrations, failure of maternal recognition of hours.1,27 Opsonins from the circulation are pregnancy, and several other causes. Mares vital for efficient phagocytosis, and comple­ may have lower conception rates when bred ment is a component of opsonization. 1 The on the foal heat.28 The highest percent of pregnancy loss occurs at days 15 - 20, when *Dr. Ebert is a 1985 graduate of the College of Veteri­ maternal recognition occurs, or at days 30­ nary Medicine at Iowa State University. **Dr. Riese is a professor of Veterinary Clinical 35, just prior to when the endometrial cups Sciences at Iowa State University. form. 23

12 Iowa State University Veterinarian There are a variety of anatomical and con­ DIAGNOSING INFERTILITY genital conditions in mares that contribute to A diagnosis of infertility and its underlying infertility. Pneumovaginitis, and subsequently etiology is based on a complete and careful pneumo-uterus, result from poor conforma­ evaluation that may require several clinical tion which allows an inadequate vulvo-vesti­ and laboratory procedures. Uterine cultures, bular closure and urine pooling.20,28 Occa­ uterine cytology, endometrial biopsies, sero­ sionally' maiden mares have a persistant logy, endoscopy, , and rectal palpa­ hymen.2o Chromosomal abnormalities may tion are common techniques available to the be related to bilaterally small, smooth, soft or practitioner.20 firm, ovaries with no palpable structures.8 A general physical appraisal should be the Pathologic cystic follicles, like those in , first procedure when evaluating the reproduc­ have not been documented in mares.8 Cervi­ tive status of a mare.26 The overall condition cal lesions prevent conceptions in some of the mare in terms of her body fat can have mares, and are frequently a result of trauma a direct effect on her reproductive efficiency. from breeding or foaling. 20 Mares are most fertile when they are lean and Ovarian neoplasm can cause infertility. gaining weight.7 Any masculinity should be Three recognized categories of tumors are sex noted. cord-stromal tumors (granulosa cell tumors), The reproductive exam should begin with a primary eptithelial tumors (cystadenomas), visual appraisal of the , vagina and cer­ and germ cell tumors (teratomas and dysger­ vix. 26 Conformational and traumatic defects minoma). Of these, the granulosa cell tumors are common. Recto-vaginal tears, pneumova­ are the most common.8,24 The embryologic gina (windsucking), cervical lacerations, mus­ origin is uncertain. They produce hormones cle separation, abscesses, diverticulae, and and cause anestrous, intermittant or frequent abnormal dilatation ofthe cervix can be found estrus, nymphomania, stallion-like behavior by visual inspection with a speculum or digi­ or masculine physical characteristics in mares tally.7 A rectal exam is the most important because of the increased testosterone concen­ step in reproductive evaluations. The uterus tration.24 can be palpated to determine its tone, size, and texture. The ventral wall at the junction The serous cystadenoma is rare. Mares will of the horns is the most frequent location for cycle normally, and can become pregnant due grossly palpable uterine pathology7. Atrophy to the normal function of the opposite ovary. of , mucosal atrophy, endome- The multiple cysts eventually destroy the af­ fected ovary.20 They do not secrete hormone.

Teratomas are relatively rare and are non­ TABLE 1. Differential Diagnosis of Ovarian Enlargement8 hormone secreting. They can be quite large Granulosa Cell Persistant Follicular Ovarian Tumor Structures (Functional) Hematoma and contain bone, cartilage, hair, teeth and Age Breeding Age Usually Breeding Age Us. Br. Age nerves. They are usually unilateral and the Site Unilateral Us. Unilateral Us. Unilat. opposite ovary will cycle and pregnancy is Season All Year Breeding Season Peak Br. Sn. possible.20 Estrous Anestrus, Anestrus, Normal, Cycle Irregular Nymphomania, Fertile. Dysgerminomas are rare but are the one Charact. Cycles, Infertility. Nymphomania, malignant form of ovarian neoplasms. They Infertile. metastasize to the and thorax and Behavior Normal to Abnormal- can cause colic or rapid weight loss. 20 Virilistic, Viscious.

Endometrial cysts develop from obstructed Ovarian Varying size, Large cystic struct. Large cystic Charact. Solid, cystic, Fossa palpable. structure. lymphatics in the reproductive tract. These Indistinct Cyst fluid serous. Architecture Fossa. destroyed. cysts, if large enough, make the endometrial Serous Fluid. Bloody fld.

lining unsuitable for implantation.20 Response to Infertility can be recognized by anestrus be­ Hormones Fair havior during the breeding season in unbred Treatment Hemi-ovar- Hemi-ovariectomy. Hemi-ovar- iectomy Ovariocentesis. iectomy. mares, continuous or intermittant estrus, ag­ LH/HCG, Progesterone. Recovery.

gressive behavior, uterine discharges, or a his­ Prognosis Good Good Good tory of unproductiveness.8,24 Wk-months Days to weeks A few days

Vol. 48) No. 1 13 trial cysts, and lymphatic lacunae can be de­ there is evidence of infection visually or tected, as can atrophy of endometrial folds. biopsy indicates active inflammation.7 Dis­ Oviducts cannot be consistently palpated. charges should be noted, although only conta­ The ovaries should be examined for hypo- or gious equine metritis can be diagnoised by the hyperplasia. The normal size is 6-7.5 cm in type of discharge (grey).9 Pure cultures on length, but vary greatly in size due to the sea­ successive days are more meaningful.7 Signif­ son.7 Their consistency, and a comparison icant bacterial infections include colonies of with the opposite ovary are important to note. Streptococcus spp., E. coli, Klebsiella spp., Staphy­ An enlargement ofone ovary can indicate one lococcus spp., Proteus vulgaris, Pseudomonas aeru­ of several disease conditions. Differentials to ginosa, Corynebacterium pyogenes, Shigella equuli, consider include tumors, hematoma, or an Bacillus subtilis, Acinetobacter spp., Citrobacter enlarged lobulated ovary of older mares de­ spp., and Enterobacter spp. 26 Aspergillus spp. and veloping at the beginning of the transition pe­ Candida spp. are the primary fungal and yeast 20 riod. S Granulosa cell tumors produce hor­ organisms encountered. The incidence of mones that can be detected in the serum and endometritis increases with age and affected may be used for differentiation (See Table 1).8 mares have an increasing difficulty in carrying Ovarian hypoplasia is caused by several a pregnancy to term. 11 conditions. Seasonal anestrous causes a re­ Endometrial biopsies are used to evaluate gression ofovarian size, as does severe malnu­ inflammatory changes in the en~ometrium, trition' stress, or obesity. Chromosomal ab­ but do not necessarily identify the etiology. 6 normalities are seen occasionally and 63,XO The correlation between finding bacteria and (Turner's Syndrome) is the most common. inflammatory changes is not high, usually be­ Reproductive endocrinopathies can cause hy­ cause of a failure to recover bacteria.2 ,9 With poplasia, and can be detected by injecting ex­ an increase in endometrial fibrosis, the foaling ogenous GnRH.7 If the mare shows normal percentage drops because of a high percentage estrus behavior, forms a corpus luteum, and of embryonic death (3 -4 times normal). 12 returns to estrus 15 days after the last day of Four categories have been established as indi­ the previous estrus, it is reasonable to assume cators of periglandular fibrosis in biopsy sam­ that the endocrine system is functioning ade­ pIes. Expected foaling percentages are related quately.7 to the severity of periglandular fibrosis (See Before any contaminating intra-uterine Table 2).20 Seasonal changes influence the procedures are done, a uterine culture should be collected for identification and TABLE 2. The Relationship Between Foaling Rates and Endometrial sensitivity of uterine organisms. It is no Degeneration2O longer applicable to culture the cervix. The Degree of Percentage of Expected Neely Doig Periglandular Glandular Foaling significance of positive cultures is not always Categories Categories Fibrosis Degeneration Rate 7 clear. Healthy mares harbor bacteria in their I A Absent <10% 70-90% II high B Mild 10-35% 50-70% reproductive tracts, and these organisms «2 layers) 28 II low C Moderate 35-60% 10-50% make the recognition of disease difficult. Up (2-4 layers) III D Severe >60% <10% to 80 % of mares culture positive 72 hours af­ (>4 layers) ter breeding and from one to thirty days after foaling. 7 Generally, only mares with a ques­ tionable breeding record should have a cul­ quantitative assessment of fibrosis, and the ture performed. The sample should be taken changes may not be uniform throughout the from the uterus during mid-estrus.9 Cytology uterus. 1S Biopsies are indicated when: should be done to evaluate the uterine re­ - mares have abnormalities of the genital sponse to any bacterial contamination. Bacte­ tract. ria associated with a significant inflammatory - pyometra or mucometra is present. reaction (neutrophilia) indicate a positive cul­ - barren mares are bred 3 or more times 7 ture. ,9 Sometimes positive cultures are not with good sperm at 48 hours pre-ovula­ associated with significant histopathologic evi­ tion. dence of endometritis. 12 A positive bacterial - there is evidence of early embryonic or culture without inflammation is not signifi­ fetal death. cant, and are not needed. 10 A - non-pregnant mares are anestrus during single positive culture is insignificant unless the breeding season.

14 Iowa State University Veterinarian - genital surgery is required. tility in the mare is based on a sound knowl­ - examining for a fertilty evaluation. edge of the seasonal variations and estrous cy­ - mares are barren due to unknown cle in the mare, and its effects on the physical causes. 18,20 changes at the gross, histological, and endo­ The results are used to predict the future re­ crine levels. productive performance of the mare. 7 An internal exam of the reproductive tract THERAPY FOR INFERTILITY is accomplished by endoscopy using a fiberop­ The choice of therapy for uterine disease tic scope. This instrument is useful in visual­ depends on the diagnosed etiology, the uterine izing various abnormalities such as size and tone, the character of the endome­ transluminal adhesions, atrophy or endome­ trium, the duration of the problem, econom­ trial folds , lymphatic cysts and foreign ics, and how available the animal is for treat­ bodies. 7 Many conditions are visualized that ment. Uterine disease is categorized into a cannot be detected by palpation. Small flat non-infectious inflammation, pyometra, me­ embedded fibroses, synechiae, mucus mem­ tritis, and endometritis.26 Irrigation and infu­ branes, septa, polyps, sacculations, ulcera­ sion of the uterus is used extensively since it tions, and cysts fall into this category.29,31 En- assists in controlling infection, debriding ne­ doscopy allows the clinician to observe the crotic tissue, regulating estrous cycles, and in­ entire uterine cavity, including the horns, and ducing estrus. 11 Pressure infusion can be used thus increases the accuracy of diagnosis. 30 to introduce antibiotics, correct a pneumo­ Biopsies should be done concurrently. Endos­ uterus associated with prolonged estrus, in­ copy is indicated in the following situations. crease uterine tone, induce estrus, and is of­ 1. When evacuating abnormal discharges ten used with chronically affected mares.28 from postpartum mares. Non-infectious inflammation is generally 2. In infertile mares with a history of abor- treated by physical or chemical curettage, es­ tion or resorption. pecially in animals with normal estrus/ova­ 3. In severe purulent endometritis. ries, and with early abortion. 26 ,33 4. When there is uterine pathology. Pyometra therapy must initiate estrous. To 5. During tubal cannulation. accomplish this, the uterus is flushed with a 6. When there is a suspected foreign body. dilute antiseptic (1 % Lugol's) by infusing and 7. For direct cultures. siphoning 500-2000 mls at a time. This stim­ 8. For direct biopsy. 29 ulates the release of luteolytic factor and CL Ultrasound, as a tool in the diagnosis of regression. Prostaglandin can also be used ex­ reproductive conditions, is a fairly new devel­ ogenously. The uterus decreases in size and opment. The interpretation of readings re­ increases in tone. Two to four treatments are quires that one's knowledge of anatomy be usually required. Once the uterus has re­ adapted to cross-sectional readouts. Ultra­ turned to a more normal size, antibiotics are sonic anatomy of the uterus is influenced by infused. 26 Cervical adhesions are often a com­ the stage of the and is dependent plication of pyometra, and even with rigor­ on prevailing circulating levels of ovarian ste­ ous, conscientious therapy, the prognosis re­ roids. 14 Ultrasound is most frequently used mains poor for future reproductive for early pregnancy diagnosis, and is highly capabilities. accurate at 15 days, although best at 20-24 Metritis therapy is similar to treatment for days.34 False negatives are rare and no false pyometra except that prostaglandins are used positives are observed.23 It is useful for the to evacuate the uterus and shorten the cycle. detection of twins, false pregnancies, and Antibiotics and/or antiseptics are then used.26 open mares.34 Alternative therapy includes plus Serology can be used for pregnancy detec­ oxytocin in place of the prostaglandins. tion by detecting PMSG (EgCG). It appears Endometritis therapy is aimed at eliminat­ in the blood on day 35-40, peaks between ing any predisposing factors, employing local days 65 - 75, and disappears around day and systemic antibiotics, and utilizing chemi­ 120.22 Two tests are commercially available cal antiseptics, plasma or colostrum, and hor­ for the practitioner, D-Tec* MP and MIP­ mones.20 ,26 Chemical curettage is employed in Test®.35,36 non-infected endometritis.26 Treatment of in­ Adequate diagnosis and treatment of infer- fectious endometritis is aimed at a specific

Vol. 48) No. 1 15 spectrum of bacteria or fungi according to the TABLE :3. Guidelines for the Administration of Intrauterine Drug~20 culture sensitivity (CIS) results. In the ab­ Drug Dosage Comments Penicillin K + 5 X 106 U Very effective for Strept. Economical. sence of CIS, a broad spectrum antibiotic Commonly used. Gentamicin S04 500-1000mg Very effective, non-irritating when should be used. Systemic dosage rates and fre­ diluted. quencies are used as guidelines for infusing Ampicillin 1-3 g Irritating if not diluted. the medication. 7 The antibiotic is diluted in at Carbenicillin 2-5 g Used for persistant Pseudomonas. Slightly irritating. least 120 mls of water or saline, and repeated Ticarcillin 1-3 g U sed for Pseudomonas. Do not use for daily for 3-5 days, up to 14 days. An indwell­ Klebsiella. S04 2 g U sed for persistant Pseudomonas, ing catheter is helpful when prolonged Klebsiella, and persistant gram negative therapy is indicated. 7 Intra-uterine infusions organisms. of the mare's own plasma (collected at estrus) Kanamycin S04 1 g Toxic to sperm. Polymyxin B 1 X 106 U U sed for Pseudomonas. help to bring about a clinical improvement of Neomycin S04 3-4 g U sed for sensitive E. coli. endometritis, due to serum-derived opsonins Chloramphenicol 2-3 g Irritating, especially orally. (complement) that enhance the phagocytic Nitrofurazones 50-60ml Questionable effectiveness.

Povodone-12 250ml Good irrigation for nonspecific rate of bacteria.3,4 Colostrum can also be used (1-2% of stock) inflammation, and for yeast. Irritating if for intra-uterine therapy. Colostral contact >10%. Chlorhexidine 250ml Irrigation for nonspecific inflammation. with the uterus favorably influences the hor­ Irritating if > 5 % or in suspension form. monal control of the estrous cycle. Mare col­ Nystatin 500,000 U For yeast. Dilute in 100-250ml water. ostrum contains 6g/dl of IgG, which can com­ Amphotericin B 200mg For fungi. Dilute in 100-250ml water. Dimethylsulfoxide 50-100ml Penetrating agent to carry drugs. pensate for a deficiency of IgA at the uterine (5 % of stock) Effectiveness and safety unknown. secretory surface. The effects of colostral EDTA-TRIS 250 ml, Theory: EDTA binds Ca + + in (1.2g NaEDTA+ 3 hours bacterial cell walls, making more treatment persist through one estrous cycle to 6.05g TRIS/L later use permeable to antibiotic. 11 water, to pH 8 IU anti- early pregnancy or even 10nger. It has been glacial acetic biotic recommended that 120 ml of mare's colostrum acid) in 380 mls of saline be infused during mating estrus. 11 However, the uterine size should be determined by rectal palpation to avoid over­ absorption. 16 It is active against Strep. spp. infusion of the uterus and to insure an ade­ which is involved in 50-65% of infections. quate dosage. An undistended maiden mare's Chloramphenicol is bacteriostatic against uterus has a capacity of about 35 mIs, while Staph. spp.) Strep. spp.) E. coli) Proteus spp.) and an older mare may hold 60-150 mls. 20 The Klebsiella spp. It is rapidly absorbed after in­ mare should be cultured 30 days after treat­ trauterine infusion, blood levels peak in less ment. 7 than 1 hour, and it lasts 12 hours. 16 Oxytetra­ When considering therapy, it is important cycline is useful in only a limited number of to remember that a genital infection is rarely infections, and it is poorly absorbed from the localized only to the uterine cavity, but usu­ uterus to the bloodstream. 16 Gentamycin is an ally affects other associated tissues such as expensive drug, but causes no uterine inflam­ myometrium, serosa, vagina, cervix, ovi­ mation and is effective against Staph. spp.) ducts, etc. 16 The pharmacological agents used Pseudomonas spp.) Klebsiella spp.) Proteus spp.) E. in the therapy of uterine dis~ase ar-e antisep­ coli) Step. spp. and Hemophilus equigenitalis tics, antibiotics, and antimycotics (See Table (CEM). Ampicillin is similar in action to 3).26 A popular antiseptic is Lugol's 1-2%. It penicillin. Intravenous administration (7 -10 is vital that it be diluted or severe damage to mg/kg) is effective for treatment of B-hemo­ the uterus, cervix, and vagina may result. lyzing streptococci. 16 Dihydrostreptomycin is Clinical signs of chemical damage look like not effective against any organisms found in colic: straining, increased heart and respira­ the uterus. Nitrofurazone is effective towards tory rate, sweating and trembling.26 some uterine pathogens, as is amikacin. A number of antibiotics are available for When a fungal infection is suspected, anti­ use. Ofthese, penicillin K, 2 million units, for biotic treatment should be stopped, and any 3 days is perhaps the most effective. It is read­ other underlying causes corrected (e. g. ily absorbed from the uterus, but its duration pneumovagina). Antimycotic agents such as of action is only a few hours. The mare's hor­ iodine or nystatin may result in successful monal status does not influence the plasma treatment.26 Iodine 1-4 % solution is the levels of penicillin, but mechanical irritation cheapest and mostly widely used treatment, of the uterus before infusion results in greater but is not always satisfactory. Nystatin

16 Iowa State University Veterinarian (500,000 IV, 4-5 days), amphotericin B, and Several disadvantages result from uterine clotrimazole (400-600 mg every third day for antibiotic therapy. The estrous cycle may be 3-4 treatments) may be the best treatments lengthened or shortened. Fungal infections available. Clotrimazole is a human drug used may develop. A low dose or the incorrect anti­ as a suppository. 17 biotic may cause resistance. Systemic effects Hormones can be used in combination with can result from absorption. Some antibiotics antibiotics or alone to treat several disease are irritating and can cause endometrial dam­ conditions. A sensitive antibiotic + age. A post-breeding infusion may decrease in solution (e.g. ethinyl estradiol + nitro­ the foaling rate. 26 furathiazide) stimulates the expulsion of ex­ udate from the uterus. 10 Prostaglandins cause CONCLUSIONS a longer follicular phase. Prostaglandin F2a, The causes of infertility in the mare are 10-15 mg, once subcutaneously, is used, many and varied, and result in considerable when a mare is having a prolonged luteal economic loss for the breeder. The more com­ function, to cause ovulation. The mare will mon factors contributing to reproductive not always respond to teasing, even if ovula­ losses, and methods available to the practi­ tion occurs.7 This same drug can be used to tioner for their diagnosis and treatment have shorten the estrous cycle. Commonly it is been outlined here. given 5-6 days after the ovulation of the first foal heat, after which the mare will have a new heat in 2-5 days. This is useful for late REFERENCES foalers whose conception rate on the foal heat 1. Asbury, AC: Practical Application of Intrauterine would be 10-15 % lower. Progesterone has Plasma as a Treatment for Equine Endometritis. been advocated for chronic aborters, although January 1984 (Personal communication) 2. Asbury, AC: Some Observations on the Relationship its effectiveness is not documented, nor has of Histologic Inflammation in the of the loss of pregnancy due to a true proges­ Mares to Fertility. Proceedings of the 28th Annual Con­ vention ofAAEP December 1982. terone deficiency been established. If used, a 3. Asbury, AC; Gorman, NT; Foster, GW: "Uterine dosage of 150 mg in oil daily or 2000 mg repo­ Defense Mechanisms in the Mare: Serum Opsonins sitory weekly is recommended, for the first Affecting Phagocytosis of Streptococcus zooepidemi­ cus by Equine Neutrophils." Theriogenology 21(2) 375­ 100 days of pregnancy until the placenta takes 385, Feb. 1984. over the production of this horn10ne from the 4. Asbury, AC: Uterine Defense Mechanisms in the CL of the ovary. 7,20 Mare; The Use of Intrauterine Plasma in the Management of Endometritis. Theriogenology 21 (2) Environmental factors can cause infertility 387 -393, Feb 1984. in mares, one of which is seasonal day length. 5. Bergeron, Helene; Crouch, GM; Bowen, JM: For mares that will be bred early in the sea­ Granulosa Theca Cell Tumor in a Mare The Compen­ dium on Continuing Education 5(3) S141-S144, Mar son, artificial lighting can help to improve the 1983. pregnancy rate. Fifteen to 16 hours per day 6. Blanchard, TL; Garcia, MC; Hurtgen, JP; Kenney, RM: Comparison of Two Techniques for Obtaining by the onset of the breeding season, and al­ Endometrial Bacteriologic Cultures in the Mare. lowing 6 weeks to respond, starting in Decem­ Theriogenology 16(1) 85-93, July 1981. ber, is necessary.7 7. Blanchard, TL; Woods, GL: Reproductive Manage­ ment ofthe Barren Mare. The Compendium on Continu­ Surgery is the treatment of choice for ovar­ ing Education (9) S141-S147, Sept 1980. ian neoplasms. Normal behavior patterns 8. Bosu, WTK; Van Camp, SC; Miller, RB; Owen, R usually return in a few days.5,8,24 Caslicks pro- ap R: Ovarian Disorders: Clinical and Morphologi­ cal Observations in 30 Mares. Canadian Jleterinary cedure is done on mares that are windsuckers Journal 23: 6-14, 1982. as soon as possible after foaling. 7 Surgeries 9. Brook, Derek: The Diagnosis of Equine Bacterial Endometritis. The Compendium on Continuing Education can also be performed for cervical lacerations, 6(5) S300-S307, May 1984. urine pooling, and rectovaginal fistulas. 7,10 10. deGannes, RVG: Old and New Uterine Treatments Treatment failures stem from many factors. for Broodmares. Proceedings of the 28th Annual Conven­ tion ofAAEP December 1982. The use of an incorrect antibiotic (resistance), 11. Dewes, HF: Preliminary Observations on the Use of or the use of antibiotics where there is no in­ Colostrum as an Uterine Infusion in Thoroughbred Mares. New Zealand Jleterinary Journal 28: 7-8. fection is common. Antibiotics in combina­ 12. Doig, PA; McKnight, JD; Miller, RB: The Use of tion with another incompatible antibiotic or Endometrial Biopsy in the Infertile Mare. Canadian drug causes unsatisfactory results. Treatment Veterinary Journal 22: 72 -76, 1981. 13. Dorland's Illustrated Medical Dictionary, 24th edition, after permanent severe degenerative changes W.B. Saunders Co., Philadelphia and London, also is useless.26 1965.

VOL. 48) No. 1 17 14. Ginther, OJ and Pierson, RA: Ultrasonic Anatomy logical Changes and Endocrinological Secretory Pat­ and Pathology of the Equine Uterus. Theriogenology terns in Mares With Ovarian Tumors. j. Reproduction 21(3) 505 -516, Mar 1984. and Fertility) Suppl. 27: 277-285, 1979. 15. Gross, TL and LeBlanc, MM: Seasonal Variation of 25. Strzemienski, PJ; Kenney, RM: Effect of Stage of Histomorphologic Features ofEquine Endometrium. Cycle, Sampling Frequency, and Recovery of Micro­ jAVMA 184(11) 1379-1382, June 1,1984. organisms on Total Protein Content of Mare Uterine 16. Gustafsson, BK: New Aspects on Antibiotic Treat­ Flushings. j. Reproduction and Fertility 70(1) 327-332, ment of Genital Infections. Proceedings oj the Annual 1984. Meflting oj the Society jor Theriogen 0 logy. pp. 219-224, 26. Threlfall, WR: Broodmare Uterine Therapy. The 1980. Compendium on Continuing Education 2(11) S246, 1980. 17. Hurtgen, JP; Cummings, MR: Diagnosis and Treat­ 27. Williamson, P; Dunning, A; O'Connor, J; Penhale, ment of Fungal Endometritis in Mares. Proceedings oj WJ: Immunoglobulin Levels, Protein Concentra­ the Annual Meeting oj the Society jor Theriogenology) pp. tions and Alkaline Phosphatase Activity in Uterine 18-22, 1982. Flushings From Mares With Endometritis. The­ 18. Kenney, RM: Cyclic and Pathologic Changes of the riogenology 19(3) 441-448, Mar 1983. Mare Endometrium as Detected by Biopsy, With a 28. Wilson, GL: A Modified Treatment of the Equine Note on Early Embryonic Death. jAVMA 172(3) Uterus. VMISAC 76: 493-502, Apr 1981. 241-262, Feb 1,1978. 29. Wilson, GL: Equine Hysteroscopy: A Window to the 19. Maher, JM; Squires, EL; Voss, JL; Shideler, RK: Tract. VM/SAC 78(4) 568-578, 1983. Effect of Anabolic Steroids on Reproductive Func­ 30. Wilson, GL: Equine Hysteroscopy: Normal In­ tion of Young Mares. jAVMA 183(Sept 1, 1983)5: trauterine Anatomy. VMISAC pp. 1388-1393, Nov 519-524. 1984. 20. Neely, DP; Liu, IKM; Hillman, RB: Equine Repro­ 31. Wilson, GL: Laparoscopic Examination of Mares. dUdion. Veterinary Learning Systems Co., Inc. 1983. VMISAC 78(10) 1629-1633, Oct 1983. 21. Sulomon, WJ; Schultz, RH; Fahning, ML: A Study 32. Winter, AJ: Microbial Immunity in the Reproduc­ of Chronic Infertility in the Mare Utilizing Uterine tive Tract. jAVMA 181(10) 1069-1073, Nov 15, Biopsy, Cytology and Cultural Methods. Proceedings 1982. oj the 18th Annual Convention oj the AAEP 1972. 33. Witherspoon, DM: Technique and Evaluation of 22. Squires, EL; Voss, JL; Villahoz, MD: Immunologi­ Uterine Curettage. Proceedings oj the Annual Convention cal Methods for Pregnancy Detection in Mares. Pro­ oj the AAEP.' pp. 51-53, 1972. ceedings oj the 29th Annual Convention oj the AAEP De­ 34. Zent, WW: Use of Ultrasound in Broodmare Prac­ cember 1983. tice. Proceedings oj the 29th Annual Convention oj the 23. Squires, EL; Voss, JL; Villahoz, MD; Shideler, RK: AAEP December 1983. Use of Ultrasound in Broodmare Reproduction. Pro­ 35. D-Tec* MP, Pitman-Moore, Inc. Washington Cross­ ceedings oj the 29th Annual Convention oj the AAEP. De­ ing, NJ 08560. cember 1983. 36. MIP-Test®, Diamond Laboratories, Inc. Des 24. Stabenfeldt, GH; Hughes, JP; Kennedy, PC; Moines, IA 50304. Meagher, DM; Neely, DP: Clinical Findings, Patho-

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18 Iowa State University Veterinarian