How are fleas harmful to cats? - briefly
Fleas ingest blood, causing anemia and intense itching that can develop into skin infections and allergic dermatitis. They also serve as vectors for pathogens such as Bartonella and tapeworms, creating systemic health threats.
How are fleas harmful to cats? - in detail
Fleas inflict a range of physiological and pathological problems in felines. Their blood‑feeding habit leads to immediate loss of erythrocytes and plasma, which can cause anemia, especially in kittens or small breeds that cannot compensate for the volume of blood taken. Anemia manifests as pale mucous membranes, lethargy, and rapid heart rate; severe cases may require transfusion.
The insects also serve as vectors for bacterial and protozoan agents. Bartonella henselae and Rickettsia felis are transmitted during feeding, producing fever, lymphadenopathy, and, in some instances, chronic infections that affect multiple organ systems. Dipylidium caninum, a tapeworm, uses fleas as intermediate hosts; ingestion of infected fleas during grooming results in intestinal parasitism, leading to weight loss, abdominal discomfort, and malabsorption.
Allergic responses are common. Repeated flea bites sensitize the cat’s immune system, triggering flea allergy dermatitis (FAD). Symptoms include intense pruritus, erythema, crusting, and secondary bacterial infection from self‑induced trauma. The inflammation can spread beyond bite sites, creating widespread skin lesions that impair the animal’s quality of life.
Fleas produce irritating saliva that contains anticoagulants and anti‑inflammatory compounds. These substances provoke localized vasodilation and edema, increasing the risk of ulceration and necrosis if the cat scratches or bites the area excessively. In extreme infestations, the cumulative effect of saliva and bite wounds can compromise skin integrity, facilitating opportunistic infections such as Staphylococcus or Streptococcus species.
Heavy infestations also affect the cat’s overall health by inducing stress and disrupting normal behavior. Persistent itching leads to excessive grooming, which can cause alopecia, hair breakage, and even self‑inflicted wounds. The metabolic cost of constant immune activation and skin repair diverts nutrients from growth and maintenance, potentially slowing development in young cats.
Key impacts:
- Blood loss → anemia, weakness, tachycardia
- Disease transmission → bacterial (Bartonella, Rickettsia) and tapeworm infections
- Allergic dermatitis → pruritus, skin lesions, secondary infections
- Saliva‑induced irritation → edema, ulceration, necrosis
- Behavioral stress → over‑grooming, hair loss, nutrient depletion
Prompt detection and effective flea control are essential to prevent these adverse outcomes and preserve feline health.