FIRST POTENTIAL CASE OF NOCARDIOFORM PLACENTITIS IN A MARE FROM ALABAMA S.M. Shrader 1 , J.C. Newton 1 , R.R. Wilborn 2 . 1 Department of Pathobiology and 2 Department of Clinical Sciences, Auburn University, Auburn, AL Clinical History A 14-year-old Warm Blood mare from Tallapoosa County, AL presented to the Auburn University Large Animal Teaching Hospital Theriogenology service in April 2012 for a breeding soundness examination. The horse had previously foaled twice. Examination indicated that she was a good candidate for breeding. On May 14 th , she was inseminated using a deep uterine horn insemination technique with the first dose of frozen semen, ovulat- ed overnight, and was administered the second dose of frozen semen the following morning. A follow-up exami- nation indicated that she was not pregnant. On June 4 th , she was artificially inseminated in the left uterine horn with fresh semen from one of the stallions at the AU Theriogenology center. Pregnancy was confirmed on July 9 th and the expected due date was May 31 st , 2013. The pregnancy was unenventful until she presented on Mar 26 th , 2013 for udder development (day 275 of gestation). At that time she lacked vaginal discharge and cervical dilation; however, treatment for suspected placentitis was initiated (consisting of trimethoprim sulfa, flunixin meglamine and altrenogest). Premature labor occurred on April 10 th (at 290 days gestation). The mare delivered a live foal (that was subsequently euthanized). Discussion The underlying eology of the chorionis in this case remains undetermined; however, the late-term aboron, well-demarcated avillous chorionic surface and intralesional branching filamentous Gram posive bacilli are consistent with previous reports of nocardioform placens[1]. Nocardioform pla- cens is the predominant cause of placens and reproducve loss in central Kentucky[2] and is as- sociated with species in the genus Amycolatopsis[3] and Crossiella equi[4]. This form of placens has also been confirmed in a mare and stallion in Florida and a mare and stallion in Virginia[1]. The pathogenesis of nocardioform placens connues to be debated. In general, there are two main routes of placental infecon: hematogenous spread or ascension of infecon from the cervix. Hema- togenous spread seems unlikely in this instance because in all reported cases, the nocardioform bac- teria result in a focal lesion. An ascending infecon does not seem likely either because the microvilli surrounding the cervical star are unaffected. Abstract A 14-year-old Warm Blood mare from Tallapoosa County, AL presented to the Auburn College of Veteri- nary Medicine at 275 days gestaon with premature udder development. Therapy, consisng of altreno- gest and trimethoprim/sulfamethoxazole, were iniated for suspected placens; however, premature la- bor occurred at 290 days gestaon. The mare delivered a live foal (that was subsequently euthanized) and the enre placenta was submied for gross and histopathological examinaon. On gross examina- on, the chorionic surface had a 30-cm x 40-cm, well-demarcated, pale pink-yellow area surrounded by hyperemia. In some areas, the line of demarcaon was associated with and obscured by yellowish plaques. On the allantoic side, adjacent to the umbilical cord-associated vasculature, were numerous, variably sized (up to 9-cm in diameter), ovoid to irregularly shaped, firm, moled red nodules (consistent with adenomatous hyperplasia). Histologically, the chorion had a focally extensive avillous area that was associated with a surface of degenerate epithelium. Along the periphery of this area, there were degen- erate and necroc trophoblasts with a mixed inflammatory infiltrate and numerous, variably sized, Gram posive bacilli, including some with filamentous branching. Aerobic bacterial cultures confirmed the pres- ence of numerous Gram posive bacilli. PCR was performed on a placental swab (submied to the Uni- versity of Kentucky Veterinary Diagnosc Laboratory) to test for the presence of Amycolatopsis spp. and Crossiella equi (nocardioforms known to cause placens in mares from Kentucky and Florida). Results were negave. Although neither of the previously reported nocardioforms was idenfied, based on the late gestaonal premature labor, gross findings, and histopathological observaon of placens with in- tralesional Gram posive filamentous bacteria, this case represents the first potenal occurrence of eq- uine nocardioform placens in Alabama. Diagnostics Bacteriology: A uterine culture, performed immediately following premature labor, revealed growth of unspeci- fied Bacillus spp. Frozen serum from the mare, placental and uterine swabs and placental exudate were also submitted to the University of Kentucky College of Agriculture Veterinary Diagnostics La- boratory. Their laboratory confirmed the presence of an unclassified Gram positive bacillus (consistent with Bacillus spp). Additionally, PCR was performed for the detection of Amycolatopsis and Crossiella equi (nocardioforms previously isolated from cases of equine placentitis); however, neither pathogen was detected. She was subsequently re-cultured on May 3 rd and was found to be negative for bacterial growth. Gross Placental Examination: The entire placenta was received for examination. On the allantoic side of the chorioallantois, adja- cent to umbilical cord-associated vasculature, were numerous, variably sized (up to 9-cm in diame- ter), ovoid to irregularly shaped, firm nodules with pale to dark red mottling. On cut surface, similar mottling is observed and there were numerous microcavities that contained flocculent yellowish- brown liquid. The chorionic surface of the placenta had a roughly 30-cm x 40-cm, well-demarcated, pale-pink to yellow area that was surrounded by hyperemic chorion that was variably covered by thick dark brown mucous. In some areas, the line of demarcation was associated with and focally obscured by yellowish plaques. The amnion and umbilical cord were grossly unremarkable. Figure 1: Gross image of the placenta. On the allantoic side of the chorioallantois, adjacent to umbilical cord-associated vasculature, are numerous, variably sized (up to 9-cm in diameter), ovoid to irregularly shaped, firm nodules with pale to dark red moling (adenomatous hyperplasia). The amnion and umbilical cord are grossly unremarkable. Figure 2: The chorionic surface of the placenta has a roughly 30-cm x 40-cm, well-demarcated, pale-pink to yellow area that is surrounded by hyperemic chorion that is variably covered by thick dark brown mucous. In some areas, the line of demarcation is associated with and focally obscured by yellowish plaques. Figure 3 (left, 2x, H&E): Junction of the villous and avillous chorion. The avillous area is composed of edematous and de- generate trophoblastic epithelium with few villi that are blunted and fused. Adjacent intact villi are markedly congested. Figure 4 (right, 100x oil, Gram): Gram positive filamentous branching bacilli. Figure 5 (left, 20x, H&E): Edematous and degenerate trophoblastic epithelium with villus edema, necrosis, mixed inflammatory cell infiltrates and Gram positive bacteria that include filamentous branching bacilli. Diagnostics Histopathologic Examination: Chorion: There was a focally extensive avillous area that was associated with a surface of trophoblastic epithelium that was mildly edematous with variably degenerate epithelial cells. Multifocally, and more prominent at the demarcation with the villous portion of the chorion, was villus edema, variable necrosis and sloughing, and islands of degenerate trophoblasts that were variably associated with necrotic cellular material, infiltrating neutrophils, and congested vasculature. Along the periphery of these islands, and more concentrated within areas of dense necrotic cellular debris, were variable numbers of a mixed Gram positive bacterial population that consisted of small to medium length bacilli and scattered filamen- tous branching bacilli. Villi that remained intact were multifocally blunted and fused with stromal infiltra- tion by lymphocytes, plasma cells, and neutrophils. Allantoic nodules: The nodules were composed of numerous, variably sized, multifocal to coalescing cyst- ic glandular structures that were filled with variable amounts of lightly eosinophilic proteinaceous fluid, necrotic cellular material, degenerate neutrophils, and variably sized dark purple globules. These pseudo- glands were lined by plump, sometimes vacuolated, cuboidal to squamous epithelial cells that were typi- cally 1-3 cell layers thick. The glandular structures were surrounded by a mildly edematous and congested stroma. Morphologic Diagnoses: Chorion: Chorionis, lymphoplasmacyc and neutrophilic, focally extensive, chronic-acve with tropho- blasc degeneraon and necrosis and a mixed populaon of intralesional Gram posive bacilli (including branching filamentous forms) Allantoic nodules: Adenomatous hyperplasia, mulfocal to coalescing, mild to marked, chronic-acve References 1. Christensen, B.W., et al., Nocardioform placens with isolaon of Amycolatopsis spp in a Florida-bred mare. JAVMA, 2006. 228(8): p. 1234-1239. 2. Donahue, J. and N. Williams, Emergent causes of placens and aboron. Vet Clin North Am Equine Pract, 2000. 16: p. 443-456. 3. Labeda, D., J. Donahue, and N. Williams, Amycolatopsis kentuckyensis sp. nov., Amycolatopsis lexingtonensis sp. nov. and Amycolatopsis pretoriensis sp. nov., isolated from equine placentas. Int J Syst Evol Microbiol, 2003. 53: p. 1601-1605. 4. Donahue, J., N. Williams, and S. Sells, Crossiella equi sp. nov., isolated from equine placentas. Int J Syst Evol Microbiol, 2002. 52(2169-2173).