An animal phobia is an irrational fear of some species of animal.
Typically this will be a highly specific fear of one species and may or may not be related to a prior negative experience. Common animal phobias are fears of snakes, spiders, and cats although any species is fair game for this phobia. Depending on the type of animal involved, and the victim's lifestyle, these types of phobias can range from presenting little trouble to being completely debilitating.
Phobias can be treated through exposure to the fear object and therapy aimed at anxiety reduction.
For instance, a person who has an extreme and debilitating fear of spiders may be presented with photos and videos of spiders until their anxiety at these stimuli is reduced. Eventually they may be exposed to real (harmless!) spiders in a controlled setting in order to alleviate the discomfort they feel when they encounter any eight-legged enemies in real life.