Are there any types of animals who do not have saliva?

The basic secretory units of salivary glands are clusters of cells called an acini. ... Most animals have three major pairs of salivary glands that differ in the type of secretion they produce: ... The basis for different glands secreting saliva of differing composition can be seen by examining salivary glands histologically. read more

Fish do not have saliva. There is mucus inside their mouths to lubricate food and make swallowing food easier, but they don't start chemically break down food inside their mouths and do not have salivary glands. read more

Human saliva comprises 99.5% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be extracted), enzymes (such as amylase and lipase), antimicrobial agents such as secretory IgA and lysozyme. The enzymes found in saliva are essential in beginning the process of digestion of dietary starches and fats. read more