The species most commonly in the home is the cat flea, Ctenocephalides felis . Contrary to what the name implies, cat fleas infest both cats and dogs equally.
Fleas can carry or transmit various diseases such as the bacterium that causes bubonic plague.
Fleas often cause serious allergies to infested animals and humans. Fleas General Flea Information Flea infestations are most likely to occur during the warm, moist months of the year. Long before you notice the problem the flea population may be building up where your pet normally rests. The population, in the form of eggs, larvae, and pupae has been building up all year long, but rapid development into biting adults is not completed until the temperature and humidity rise to needed levels. An allergic animal will lose hair, frequently around the base of the tail, and may repeatedly bite and scratch the area, sometimes until it becomes raw.