Evaluating the suitability of placental bovine explants for ex vivo modelling of host-pathogen interactions in Neospora caninum infections.

Bovine abortions, often caused by infectious agents like Neospora caninum, inflict substantial economic losses. Studying host-pathogen interactions in pregnant cows is challenging, and existing cell cultures lack the intricate complexity of real tissues. To bridge the gap between in vitro and in vivo models, we explored the use of cryopreserved bovine placental explants.

Impact of Overuse and Sexually Transmitted Infections on Seminal Parameters of Extensively Managed Bulls.

Natural service remains the main breeding method in extensively managed beef herds. Although the bull might be the most important factor in determining herd fertility, its importance has been largely overlooked, focusing instead on female fertility. Management of the bull is critical to maximize the opportunities for cow conception.

Added value of IgM detection and low avidity index as markers of acute bovine besnoitiosis.

Early in vivo diagnosis of bovine besnoitiosis is crucial for the success of control programmes. However, diagnosis in acutely infected animals is hindered by the low sensitivity of the available serological tools. In this study, a novel ELISA to detect specific anti-Besnoitia besnoiti IgM antibodies was developed.

Early Neospora caninum infection dynamics in cattle after inoculation at mid-gestation with high (Nc-Spain7)- or low (Nc-Spain1H)-virulence isolates.

Early Neospora caninum infection dynamics were investigated in pregnant heifers intravenously inoculated with PBS (G-Control) or 10 tachyzoites of high (G-NcSpain7)- or low (G-NcSpain1H)-virulence isolates at 110 days of gestation. Serial culling at 10 and 20 days post-infection (dpi) was performed. Fever was detected at 1 dpi in both infected groups (P < 0.

Effect of parasite dose and host age on the infection with Besnoitia besnoiti tachyzoites in cattle.

Bovine besnoitiosis is continuing to spread in Europe. Therefore, the development of ruminant animal models of infection is urgently needed to evaluate therapeutic and prophylactic tools. Herein, we studied the effect of parasite dose and host age on the infection dynamics with Besnoitia besnoiti tachyzoites in cattle in two independent experimental infections.

Influence of dose and route of administration on the outcome of infection with the virulent Neospora caninum isolate Nc-Spain7 in pregnant sheep at mid-gestation.

Experimental infections in pregnant sheep have been focused on studying the effect of the time of challenge on the outcome of N. caninum infection, whereas the impact of the dose and route of challenge has not been studied in depth. Therefore, clinical outcome, immune responses, parasite detection and burden, and lesion severity in placental tissues and foetal brains were investigated in 90-day-pregnant sheep inoculated intravenously with 10 (G1), 10 (G2), 10 (G3), or 10 (G4) tachyzoites or subcutaneously with 10 (G5) tachyzoites of the virulent Nc-Spain7 isolate and an uninfected group (G6).

Safety and efficacy of the bumped kinase inhibitor BKI-1553 in pregnant sheep experimentally infected with Neospora caninum tachyzoites.

Neospora caninum is one of the main causes of abortion in cattle, and recent studies have highlighted its relevance as an abortifacient in small ruminants. Vaccines or drugs for the control of neosporosis are lacking. Bumped kinase inhibitors (BKIs), which are ATP-competitive inhibitors of calcium dependent protein kinase 1 (CDPK1), were shown to be highly efficacious against several apicomplexan parasites in vitro and in laboratory animal models.

Comparison of paravertebral blockade techniques with and without ultrasound guidance in calves.

OBJECTIVE To compare the effectiveness of an ultrasound-guided paravertebral nerve blockade technique (UGPNB) with distal and proximal paravertebral nerve blockade techniques without ultrasound guidance (DPNB and PPNB, respectively) in calves. ANIMALS 4 calf cadavers and 7 healthy calves. PROCEDURES A suitable acoustic window was identified to facilitate access to the T13, L1, and L2 spinal nerves in cadavers and live calves.

Ultrasound-guided anaesthetic blockade of the pelvic limb in calves.

This study aimed to describe a suitable acoustic window to facilitate access to the sciatic and femoral nerves in calves and to study the effects of their blockade with local anaesthetics. The neuroanatomical and ultrasound (US) study was performed on the cadavers of 10 calves, and the effects of 2% lidocaine with epinephrine (0.2 mL/kg) were determined in five healthy calves.

Effect of vaccination of cattle with the low virulence Nc-Spain 1H isolate of Neospora caninum against a heterologous challenge in early and mid-gestation.

Live vaccines have emerged as one of the most potentially cost-effective measures for the control of bovine neosporosis. Previous studies have shown that Nc-Spain 1H is a naturally attenuated isolate of Neospora caninum and that immunisation with live Nc-Spain 1H tachyzoites generated a protective immune response in mice. The aim of this study was to evaluate the safety and efficacy of immunisation in cattle.

Experimental infection with a low virulence isolate of Neospora caninum at 70 days gestation in cattle did not result in foetopathy.

The Nc-Spain 1H isolate of Neospora caninum, which was newly obtained from the brain of a congenitally asymptomatic infected calf, demonstrated a reduced in vitro tachyzoite yield and viability rate, as well as low virulence in mouse models. The objective of the present study was to determine the ability of this isolate to induce foetal death in a pregnant bovine model. For this purpose, 13 naïve pregnant heifers were divided into three groups and were experimentally challenged with either 10(7) tachyzoites of Nc-1 (group 1, n=5), Nc-Spain 1H (group 2, n=5) isolates or phosphate-buffered saline (group 3, n=3) intravenously at 70 days of gestation.

Isolation and characterization of a bovine isolate of Neospora caninum with low virulence.

Neospora caninum tachyzoites were isolated from the brain of an asymptomatic naturally infected calf with precolostral-specific antibodies. The new isolate, named Nc-Spain 1H, was identified as a member of the N. caninum species based on its internal transcribed spacer 1 (ITS-1) sequence and was genetically characterized using microsatellite markers.