African violets are listed as a non-poisonous plant, according to the National Capital Poison Center. The American Society for the Prevention of Cruelty to Animals (ASPCA) states that it is not toxic for cats, dogs or horses.
African violets are also known as Saintpaulia, and according to Wikipedia, they have about 6 to 20 species of plants. While they are typically an outdoor plant, they are generally used as a houseplant. African violets are very sensitive to temperature changes; this can be the reason for cell collapse and leaf discoloration. They are native to Africa, especially around the Tanzanian Nguru mountains.