What do fleas cause? - briefly
Fleas transmit bacterial diseases such as plague and murine typhus, induce allergic dermatitis, and can cause anemia in heavily infested hosts. They also act as intermediate carriers for tapeworms like Dipylidium caninum.
What do fleas cause? - in detail
Fleas are hematophagous ectoparasites that produce a range of pathological outcomes in humans and animals. Their bites penetrate the skin, delivering saliva that contains anticoagulants and enzymes, which provoke immediate local reactions and can lead to secondary bacterial infection. Repeated feeding may cause:
- Dermatitis characterized by pruritus, erythema, and papular lesions; in sensitized hosts, an allergic response can develop, known as flea‑induced hypersensitivity.
- Anemia in heavily infested small mammals, especially kittens, puppies, and wild rodents, due to cumulative blood loss.
- Transmission of zoonotic pathogens, including:
- Yersinia pestis – the etiologic agent of plague, transmitted primarily by the oriental rat flea (Xenopsylla cheopis).
- Rickettsia typhi – responsible for murine typhus, spread by the cat flea (Ctenocephalides felis) after it feeds on infected rodents.
- Bartonella henselae – causes cat‑scratch disease; fleas act as vectors between cats and humans.
- Rickettsia felis – produces flea‑borne spotted fever, presenting with fever, rash, and headache.
- Induction of flea‑allergy dermatitis (FAD) in pets, a chronic inflammatory condition that requires environmental control and immunotherapy.
Beyond direct health effects, flea infestations compromise animal welfare and can precipitate economic losses in livestock and companion‑animal industries. Control strategies focus on interrupting the flea life cycle—egg, larva, pupa, adult—through regular use of insecticidal treatments, environmental decontamination, and host grooming. Early detection and integrated pest management reduce the risk of disease transmission and mitigate the physiological burden on affected hosts.