Canine herpesvirus is an infectious disease that is a common cause of death in puppies less than three weeks old. Pseudorabies is an infectious disease that primarily affects swine, but can also cause a fatal disease in dogs with signs similar to rabies.
Progestin-only birth control pills, sometimes called âmini-pills,â have several effects in the body that help prevent pregnancy: 1  The mucus in the cervix thickens, making it difficult for sperm to enter the uterus and fertilize an egg. 2  They stop ovulation, but they do not do so consistently.
The birth control pill works by stopping sperm from meeting an egg (which is called fertilization). The hormones in the pill stop ovulation. No ovulation means there's no egg hanging around for sperm to fertilize, so pregnancy can't happen. The pill's hormones also thicken the mucus on the cervix.