Ctenocephalides

Ctenocephalides is a genus of fleas in the order Siphonaptera. The two species most commonly encountered on domestic animals are Ctenocephalides felis, the cat flea, and Ctenocephalides canis, the dog flea. They are widespread ectoparasites of cats, dogs, and other mammals and can bite humans as incidental hosts.

Fleas of this genus are small and wingless, typically 1.5 to 3 millimeters long, and are characteristically laterally flattened. They feed on blood and possess specialized mouthparts. Distinguishing features include comb-like spines (genal and pronotal combs) on the head and thorax, which aid identification.

The life cycle is a complete metamorphosis: eggs laid on the host fall into the environment, where they hatch into larvae. Larvae feed on organic debris, then form pupae inside cocoons. Adults emerge when a suitable host is nearby and begin feeding. Under favorable conditions, the cycle usually completes in about two to four weeks, though adults may persist off-host for extended periods.

C. felis and C. canis infest a wide range of mammals, with domestic cats and dogs as primary hosts. They are cosmopolitan, thriving in warm and humid environments and in human dwellings, and humans can be bitten by fleas when infestations are heavy.

Health significance includes transmission of pathogens and parasites such as Dipylidium caninum. Fleas can harbor organisms like Rickettsia felis and Bartonella species. Bites cause itching and may trigger allergic reactions; heavy infestations can contribute to anemia in young animals.

Control relies on integrated measures: regular use of veterinary-approved ectoparasiticides, environmental cleaning, vacuuming, washing bedding, and treating all animals in a household to prevent reinfestation.