The present study evaluated the development of equine conceptus transferred to non-cyclic recipient mares treated with altrenogest. Twenty four mares were used as embryo recipients during the ovulatory phase (Control group; n=8) or anestrus/transitional phases (Altrenogest group; n=16) and were evaluated by transrectal ultrasonography, at five day intervals, to monitor the development of embryonic vesicles from 15 to 45 days of pregnancy and embryo proper/fetus from 20 to 60 days. Embryonic vesicle's features such as shape, embryo location within the vesicle and umbilical cord development were similar between cyclic and non-cyclic recipient mares. The embryonic vesicle and embryo proper/fetus growth was significant (P<0.05) between 15 and 60 days of gestation in Altrenogest and Control groups, except for days 20 to 30, where embryonic vesicle growth decrease was observed (P>0.05). The embryonic vesicle and embryo proper/fetus growth was similar (P>0.05) when gestational days were compared between groups. The similarity in conceptus growth between cyclic and non-cyclic recipient mares during early pregnancy indicates that the uterine environment of non-cyclic recipient mares treated with progestins provides similar conditions for the development of transferred embryos
Background: Osteosarcomas are common malignant bone tumors described in dogs, humans and cats. However, there are rare reports in horses. The tumor etiology has not been fully elucidated. Clinical signs are associated to the tumor size, location and growth characteristics. When located on the face, the most common findings are facial distortion, nasal discharge and inspiratory dyspnea. The aim of this study was to report an osteoblastic osteosarcoma in a horse, located on the right maxillary region with projections into the corresponding nostril.Case: A 6-year-old mixbreed saddle gelding, presenting bay coat was admitted to a University Hospital with a chronic sinusitis history. The animal was previously examined and treated by other veterinarians, who suspected of odontogenic maxillary sinusitis, and therefore a repulsion of the fourth premolar from the right maxilla hemiarcade was performed. However, an improvement of the clinical signs was not observed and subsequently the gelding was referred to a Veterinary Hospital. During physical examination the patient presented dyspnea, tachypnea and tachycardia. An increase on the face size was observed, together with a fetid and purulent nasal discharge. During oral cavity inspection, a diagonal wear was detected at the occlusal surface of the right hemiarcade; food accumulation was seen at the dental extraction site, and a communication with the rostral maxillary sinus was evidenced, from where a purulent fetid discharge was draining. At the radiographic exam, well defined margins of a tumor were observed, with adjacent bone lysis and the presence of a central nucleus showing a gross granular mineral radiopacity, distorting the frontal and nasal bones. During the endoscopic exam, a mass was partially occluding the right nasal cavity close to the nasal opening, which was blocking the progression of the endoscopy. However, during the left cavity inspection, at the end of the nasal septum a mass with irregular surface was detected emerging from the border of the right choana, which extended up to the nasopharynx region. The diagnosis was established based on clinical evaluation and histopathological findings of the tumor, which confirmed osteoblastic osteosarcoma. The animal was euthanized due to poor clinical conditions and prognosis. There was no evidence of metastasis to other organs during necropsy.Discussion: The majority of reported osteosarcoma cases in horses do not define the tumor histopathological subtype. The occurrence of metastasis in equine osteosarcoma is not well established, however it seems to be uncommon. It is important to emphasize the relevance of performing a necropsy in patients presenting osteosarcoma, in order to establish a pattern concerning the metastasis incidence in the species. The predominant osteosarcoma location is the mandible, although there are few reports in the paranasal sinuses and appendicular skeleton. The tumor usual location makes the treatment difficult because of the impossibility of performing a complete surgical resection, which leads to a euthanasia decision. Although osteosarcoma has been little reported in horses, it should be a differential diagnosis for facial alterations and paranasal sinuses abnormalities, which would contribute to an early diagnosis and increase the chances of a favorable prognostic.
Este artículo discute los principales aspectos del uso de protocolos hormonales basados en la aplicación de estrógeno seguido de progestágeno en receptoras anovulatorias o acíclicas, sea en anestro o transición en los protocolos de transferencia de embriones. La mayoría de las yeguas presentan comportamiento poliéstrico estacional, con lo que manifiestan estro y ciclos ovulatorios en los periodos de mayor luminosidad diaria. El ciclo reproductivo anual de las yeguas es caracterizado por la presencia de cuatro fases definidas por la dinámica folicular: de anestro, de transición de primavera, ovulatoria y de transición de otoño. Durante las fases de transición y anestro, la incidencia de las ovulaciones disminuye o es nula, lo que dificulta la sincronización de las ovulaciones entre donadoras y receptoras durante la preparación para la transferencia de embriones. Algunos estudios han mostrado que las receptoras anovulatorias/acíclicas mantenidas con protocolos con base en esteroides presentan cambios uterinos similares a los que pasan en las yeguas gestantes. Sin embargo, no hay investigaciones suficientes que permitan aclarar el mejor protocolo de esteroides, con respecto a dosis, tiempos de tratamiento y vías de administración.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.