Fleas

The Ctenocephalides felis, more commonly know at the cat flea, is the kind of flea found on pets 99.9% of the time. The cat flea is not at all selective about its host. Conditions brought about by flea infestation include : Flea Allergic Dermatitis, Flea Anemia, Feline Infection Anemia (a life-threatening blood parasite), Cat Scratch Fever (infected cat can make a person sick), Common Tapeworm infections. Fleas can kill pets. Fleas can cause a slow but still life-threatening blood loss. 

Ticks

Ticks are skin parasites that feed on the blood of their hosts. Ticks like motion, warm temperatures from body heat, and carbon dioxide exhaled by mammals, which is why they are attracted to such hosts as dogs, cats and other small mammals. The bite itself is not usually painful, but the parasite can transmit diseases and cause tike paralysis, which is why tick control is so important. Ticks can transmit disease to pets and humans that the ticks contract from a previous host. Lyme disease is one of the most common diseases that can be contracted from ticks.