Final answer:
Spontaneous abortions in animals can be caused by infections such as by the bacterium Listeria monocytogenes. Meningitis in animals can be caused by a variety of pathogens with bacteria like Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae being the most serious and common causes.
Step-by-step explanation:
Spontaneous abortions in animals can be due to a variety of factors, one of which includes infections by certain pathogens capable of crossing the blood-placental barrier. For instance, the gram-positive bacterium Listeria monocytogenes, is known for causing listeriosis and can lead to spontaneous abortions if it infects the fetus.
Meningitis in animals is usually caused by different types of pathogens, including bacteria, viruses, fungi, and parasites. Bacterial meningitis is particularly serious and can be caused by several pathogenic bacteria that are commonly found in healthy people, such as Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. These bacteria spread through respiratory secretions and are known to cause severe illness and death if not properly treated with antibacterial therapy.