Also called dental calculus, tartar is when dental plaque builds up. Bacteria begin to organize and produce toxins that can lead to gingivitis. Due to the fact that the animals do not have their teeth brushed correctly, this plaque buildup becomes larger until it calcifies, forming the tartar.Besides the visual issue, the first symptom that shows the existence of tartar is bad breath. This condition can progress to chronic gingivitis, leading to tooth loss and in more chronic cases, vital organs such as kidneys, liver and heart can be affected.