Toxoplasma-induced abortion in dairy goats

Area of Science:

• Veterinary Parasitology
• Infectious Diseases
• Reproductive Biology

Background:

• Toxoplasma gondii is a significant cause of reproductive losses in livestock.
• Understanding transmission dynamics and fetal invasion is crucial for disease control in goats.

Purpose of the Study:

• To investigate the effects of varying Toxoplasma gondii oocyst doses on pregnant goats.
• To determine the timing of transplacental transmission and fetal tissue distribution of T. gondii.

Main Methods:

• Pregnant goats serologically negative for T. gondii were orally inoculated with 10, 100, or 1,000 oocysts.
• Control goats were non-inoculated.
• Clinical signs, reproductive outcomes, and fetal/kid tissues were assessed; infectivity was confirmed by mouse inoculation.

Main Results:

• Inoculated goats exhibited fever and dyspnea. Reproductive outcomes included abortion, stillbirths, and live-born infected kids.
• T. gondii was isolated from fetal placentas as early as 10 days post-inoculation.
• Transplacental invasion occurred between 11 and 15 days post-inoculation, with the parasite frequently detected in skeletal muscle, heart, lung, and brain of infected kids.

Conclusions:

• Oral inoculation of pregnant goats with T. gondii results in significant reproductive pathology.
• The timing of fetal invasion and the distribution of the parasite in offspring tissues have implications for disease management and diagnosis.