Ultrasound findings in 34 newborn foals with uroperitoneum.

BACKGROUND: Uroperitoneum is a typical disease of the newborn foal, which occurs rarely but regularly. Ultrasonography is considered the most important imaging method for diagnosing this disease. Thus far, only one older case series comprising 31 foals suffering from uroperitoneum has systematically listed results of ultrasound examinations. OBJECTIVE: This paper presents the findings of an ultrasonographic examination of 34 foals with uroperitoneum in order to inform future interpretation of ultrasonographic data in suspected uroperitoneum cases. METHOD: Ultrasonographic data of 34 neonatal foals up to the age of 14 days diagnosed with uroperitoneum between 2006 and 2022 were analysed. RESULTS: Most foals demonstrated highly increased levels of free (97%), anechogenic (91%) fluid in the abdomen. Although the urinary bladder was frequently visible (50%), bladder wall discontinuity was only occasionally detectable (18%). CONCLUSION: Transabdominal ultrasonography has proved to be a very reliable imaging method for diagnosing suspected uroperitoneum. It is recommended that it be used in every case of suspected uroperitoneum in order to exclude differential diagnoses.

Induction of NETosis in ovine colostral PMN upon exposure to Neospora caninum tachyzoites.

Colostrum is one of the most important factors influencing the health and development of mammalian neonates. It is well-established that leukocytes, including polymorphonuclear neutrophils (PMN), migrate from the mother to the infant via colostrum uptake. In this study, for the first time, we studied the ability of ovine colostral-derived PMN to extrude neutrophil extracellular traps (NETs) against the abortive apicomplexan parasite Neospora caninum. Although this cell population plays a significant role in the transmission of maternal innate immunity to neonates, little is known about colostral PMN activities in sheep. However, this cell population is a significant source of the transfer of maternal immunity to the neonate. Colostral PMN continues to exert immunological effects even after transitioning into the colostrum. The present study aimed to investigate the extrusion of NETs by ovine colostral PMN exposed to the apicomplexan parasite, N. caninum, which is known to cause devastating reproductive disorders in cattle, small ruminants, wildlife animals, and dogs. The present study is the first to demonstrate that ovine colostral PMN can produce NETs after stimulation with vital N. caninum tachyzoites. Ovine colostrum-derived NETs were detected by chromatin staining and antibody-based immunofluorescence staining of NET-specific structures, including neutrophil elastase (NE) and global histones (H1, H2A/H2B, H3, H4), as well as scanning electron microscopy (SEM) analysis.

Neospora caninum-induced NETosis in canine colostral polymorphonuclear neutrophils.

Neospora caninum represents an obligate intracellular apicomplexan parasite of the family Sarcocystidae causing severe reproductive disorders in cattle, small ruminants, wild animals and canids worldwide. Neutrophil extracellular traps (NETs) were recently described as effective host defense mechanism of polymorphonuclear neutrophils (PMN) derived from cattle, dogs, goats and dolphins against N. caninum tachyzoites. Nonetheless, nothing is known so far on canine colostral PMN immune reactions against N. caninum although breeding bitches represent a susceptible dog cohort and infected bitches may spread tachyzoites through transplacental transmission to their offspring. Thus, isolated colostrum PMN from bitches were assessed for PMN phagocytic activities as well as NETs release against viable N. caninum tachyzoites. In vitro interactions of canine colostrum-derived PMN with tachyzoites were analyzed at different ratios and time spans. Extracellular chromatin staining was applied in order to unveil classical molecules of NETs, such as neutrophil elastase (NE), global histones (H1, H2A/H2B, H3, H4) and myeloperoxidase (MPO), via antibody-based immunofluorescence microscopy analysis. N. caninum tachyzoites induced canine NETs in colostral PMN and scanning electron microscopy (SEM) analysis revealed NETs formation by colostral PMN thereby ensnaring tachyzoites after exposure. In summary, NETs released from canine colostral PMN might represent an early and effective maternal defense mechanism of the definitive host helping neonates to reduce initial intracellular replication of not only parasites but of other invasive pathogens after colostrum consumption.

[Occurrence and importance of colostral leukocytes]. / Vorkommen und Bedeutung von Leukozyten im Kolostrum.

Leukocytes have been identified as a physiological component of colostrum in numerous animal species. In each of the examined species, they have been shown to occur in a typical amount exhibiting slight differences in the composition of leukocyte subpopulations. According to previous opinions, colostral leukocytes merely accidentally transfer from blood to milk or represent a sign of mastitis. In contrast to this, it is now considered to be current knowledge that special mechanisms exist enabling these leukocytes to actively transfer into colostrum. The presented review provides an overview of the recent literature and demonstrates the significance of colostral leucocytes. In analogy to the passage of maternal immunoglobulins, colostral leukocytes migration also leads to a transition of immunity. The cells are enterally absorbed and distributed throughout the neonatal organism. Colostral leukocytes are found to accumulate in certain tissues and organs without losing their immunologic function. Merely the leucocytes of the own mother are absorbed and these cells complement the newborns' immune system. As several studies have demonstrated, this is not solely due to the cells' mere immunological function but also a consequence of a regulatory effect on the neonatal immune system. Especially T-helper and further regulatory cell types transferred via colostrum may help the newborn in optimizing and maturing their immunological situation. Colostral treatment methods such as mixing, freezing, heating and acidifying modifications warrant re-evaluation taking the above aspects under consideration.