Placentite em éguas: Uma revisão

Placentitis is one of the main causes of abortion, stillbirth, perinatal loss and difficulty in conceiving in the subsequent reproductive season. The objective of this work is to review aspects related to etiology, clinical signs, diagnostic methods and treatment of placentitis in mares. The equine placenta is attached to the endometrium through micro-cotyledons, with the exception of the cervical star, and the region is most affected by the condition. The main etiological agent of placentitis is bacteria, followed by fungi, viruses and protozoa. The uterine contamination due to failure of the anatomic barriers is the fundamental predisposing factor. The main clinical signs are early lactation, vaginal discharge, fetal death and miscarriage. One of the forms of diagnosis is made through ultrasonography, evaluating the placenta, uterine fluid and the concept. There is no definite treatment, but the goal is to combat infection, reduce inflammation and control myometrial activity. The prognosis for both mare and foal is variable, depending on the time of gestation, degree of infection and efficacy of the treatment. It is important to monitor the final third of gestation of the mares, favoring the early diagnosis to be successful with the treatment and birth of a healthy foal.A placentite é uma das principais causas de abortamentos, natimortos, perda perinatal e dificuldade em conceber na temporada reprodutiva subsequente. O objetivo deste trabalho e revisar os aspectos relacionados com a etiologia, sinais clínicos, métodos diagnósticos e tratamento da placentite em éguas. A placenta equina é fixada ao endométrio através de microcotilédones, com exceção da estrela cervical, sendo a região mais afetada pela afecção. O principal agente etiológico da placentite são as bactérias, seguidas dos fungos, vírus e protozoários. A contaminação uterina decorrente de falha das barreiras anatômicas é o fator predisponente fundamental. Os principais sinais clínicos são lactação precoce, corrimento vaginal, morte fetal e abortamento. Uma das formas de diagnostico e feita através da ultrassonografia, avaliando a placenta, fluido uterino e o concepto. Não há tratamento definido, mas o objetivo é combater a infecção, reduzir a inflamação e controlar a atividade do miométrio. O prognóstico tanto para a égua quanto para o potro é variável, dependendo do tempo de gestação, grau de infeção e eficácia do tratamento. É importante monitorar o terço final de gestação das éguas, favorecendo o diagnóstico precoce para obter sucesso com o tratamento e nascimento de um potro saudável

Effect of fixative type and fixation time on the morphology of equine preantral ovarian follicles

O objetivo deste estudo foi investigar a eficácia dos fixadores teciduais Bouin, Carnoy ou Formol 10% em fragmentos ovarianos equinos. Ovários (n=4) de éguas, sem raça definida, foram obtidos de abatedouro local e transportados em recipiente térmico a 20 ºC. Imediatamente após a coleta, os ovários foram lavados com solução de PBS modificado (Cultilab®, Campinas-SP, Brasil), e divididos em nove fragmentos com aproximadamente 5x5x1 mm, retirados do parênquima de cada ovário. Em seguida, os fragmentos ovarianos foram imersos em um dos três diferentes fixadores, Bouin (B), Carnoy (C) ou Formol 10% (F), por 6, 12 ou 24 horas. Cada fragmento foi acondicionado individualmente em um frasco contendo aproximadamente 20 vezes o volume da solução fixadora. Após este período, foram mantidos em álcool 70% por 24 horas. Para cada fixador e tempo foram realizadas quatro réplicas. No processamento histológico, os fragmentos foram desidratados em concentrações crescentes de álcool, diafanizados em xilol e incluídos em parafina. Em seguida, foram feitos cortes seriados de 5 ?m em micrótomo rotativo (Leica®, Wetzlar-Alemanha), seguidos da montagem de lâminas e coloração com ácido periódico de Schiff (PAS) e hematoxilina. Foram avaliadas 540 lâminas com 1.620 cortes histológicos, contendo 465 folículos pré-antrais que foram classificados como íntegros ou degenerados. A degeneração foi detectada pela presença de pelo menos um dos seguintes aspectos: retração do citoplasma, núcleo picnótico, vacúolos citoplasmáticos, deslocamento das células da granulosa e/ou rompimento da membrana basal. Um teste de regressão logística foi utilizado para a análise estatística, e as diferenças foram consideradas significativas quando P<0,05. O fixador Carnoy utilizado por 24 horas proporcionou as melhores condições de integridade morfológica (53,3%; 32/60) em relação aos demais, sendo Boiun por 24 h o tratamento menos eficaz (19,1%; 9/47). Os demais tratamentos apresentaram os resultados a seguir: C12h 50% (30/60), C6h 40% (24/60), F24h 37,8% (17/45), F12h 35,1% (13/37), F6h 32% (16/50), B12h 30,5% (18/59) e B6h 24,4% (11/45). Portanto, sugerimos que a fixação de tecido ovariano equino com Carnoy por 24 horas é o mais indicado para preservação morfológica de folículos pré-antrais.The aim of this study was to investigate the efficacy of the tissue fixatives Bouin, Carnoy and 10% Formaldehyde in equine ovarian fragments. Ovaries (n=4) from mares of mixed breeds were obtained at a local slaughterhouse and transported at 20 ºC in a thermo container. Immediately after collection, the ovaries were washed with a modified PBS solution (Cultilab®, Campinas-SP, Brazil) and divided into nine fragments with approximately 5x5x1 mm, removed from the parenchyma of each ovary. The ovarian fragments were then immersed in three different fixatives, Bouin (B) Carnoy (C) or 10% Formaldehyde (F) for 6, 12 or 24 hours. Each fragment was individually immersed in a 20 mL tube containing 20 times the volume of fixative solution. After this period, the fragments were held in 70% ethanol for 24 hours. Each procedure was performed in four replicates. For histological analysis, the specimens were dehydrated in increasing concentrations of alcohol, submitted to diaphanization in xylol and embedded in paraffin. Serial sections of 5 ?m were made with the use of a rotating microtome (Leica® type, Wetzlar, Germany), followed by slide mounting and staining with periodic acid-Schiff (PAS) and hematoxylin. A total of 540 slides with 1,620 sections were evaluated, which contained 465 preantral follicles that were classified as normal or degenerated. Follicles were considered as degenerated when presented at least one of the following aspects: cytoplasm retraction, pyknotic nucleus, cytoplasmic vacuoles, displacement of granulosa cells and/or disruption of the basal membrane. A logistic regression test was used for statistical analysis, and differences were considered significant when P<0.05. The Carnoy fixative, when used for 24 hours, provided the best conditions of morphological integrity (53.3%; 32/60) compared to all others, and the use of Boiun for 24 hours was considered the worst treatment (19.1%; 9/47). The other treatments lead to the following results: C12h 50% (30/60), C6 H 40% (24/60), F24h 37.8% (17/45), F12h 35.1% (13/37), F6h 32% (16/50), B12h 30.5% (18/59) and B6h 24.4% (11/45). Therefore, we suggest that fixation of equine ovarian tissue with Carnoy for 24 hours is the most suitable protocol for morphological preservation of pre-antral follicles

Recovery of equine oocytes by scraping of the follicular wall with different specifications of needles and morphological analysis of cumulus oophorus

In follicular aspiration, physical aspects are of high significance for the technique to succeed, such as vacuum pressure, caliber of the needle and the way the follicular wall curettage is performed. The aim of this study was to investigate the recovery rate of equine oocytes aspirated by scraping of the follicular wall, testing different calibers of disposable needles, as well as the morphological evaluation of the cumulus oophorus complexes (COCs). Mares ovaries (n=447) obtained at a local slaughterhouse were transported to the laboratory in a thermal container (20 °C) and had the tunica albuginea and connective tissues dissected. The aspirated follicles had 10 to 25 mm in diameter, and 30x8 (21G 1 ¼) or 40x12 (18G 1 ½) needles were used for the aspiration, forming group A (G-A) and group B (G-B), respectively. In G-A and G-B, 480 and 548 follicles were aspirated, respectively. Under the stereomicroscope, the oocytes were evaluated according to the quality of the ooplasm and characteristics of the cumulus cells (grade I, II, III and denuded). The statistical analysis was performed using the Student’s t-test, logistic regression and test of proportions, and differences were considered significant when P&lt;0.05. There was no difference between recovery rates of groups G-A (66.5%; 330/496) and G-B (65.5%; 359/548). In the G-A group, grade II oocytes were related to higher recovery rates (46.9%; 145/330) than grade I (23.6%; 72/330), grade III (20.6%; 59/330) and denuded oocytes (8.5%; 24/330; P&lt;0.05). However, in G-B, there was no statistical difference regarding the quality of the recovered oocytes: grade I (23.4%; 77/359), grade II (43.2%; 145/359), grade III (22.5%; 73/359) and denuded (11.1%; 32/359). The 30x8 (21G 1 ¼) needle provided a higher proportion of grades I and II oocytes than the 40x12 (18G 1 ½) needle, with 72.4% (239/330) and 65% (233/359; P&lt;0.05), respectively. Both calibers of needles tested in this study provide efficient oocyte recovery rates. Aspiration with 30x8 (21G 1 ¼) needles resulted in a higher proportion of morphologically good equine oocytes for use in reproductive biotechnologies. </p