How are fleas harmful to a cat? - briefly
Fleas drain blood, causing anemia, and serve as vectors for parasites and bacterial pathogens that irritate the skin and provoke disease. Severe infestations can lead to weight loss, fever, and allergic dermatitis.
How are fleas harmful to a cat? - in detail
Flea infestations expose cats to a range of serious health problems. Blood loss from frequent feeding can lead to anemia, especially in young or underweight animals. An adult cat may lose up to 15 % of its blood volume during a heavy infestation, producing lethargy, pale mucous membranes, and reduced appetite.
- Skin irritation caused by flea bites triggers inflammation, hair loss, and crusted lesions.
- Flea‑allergy dermatitis develops when the immune system overreacts to flea saliva, resulting in intense itching, self‑trauma, and secondary bacterial infection.
- Vector‑borne pathogens are transmitted during feeding. Common agents include Bartonella henselae (cat‑scratch disease), Rickettsia species, and Mycoplasma haemofelis, each capable of causing fever, weight loss, and organ dysfunction.
- Tapeworm Dipylidium caninum uses the flea as an intermediate host; ingestion of an infected flea introduces the parasite, leading to abdominal discomfort and digestive disturbances.
- Flea feces, composed of digested blood, contain antigenic proteins that exacerbate dermatitis when deposited on the coat and later transferred to a cat’s paws or mouth.
Anemia results from cumulative blood extraction. In kittens, a single flea may consume a substantial fraction of total blood volume, precipitating rapid decline in hemoglobin levels and, without treatment, fatal collapse. Chronic anemia manifests as weakness, tachycardia, and impaired tissue oxygenation.
Allergic dermatitis arises from hypersensitivity to flea saliva. Clinical signs include erythema, papules, and alopecia concentrated around the tail base, neck, and abdomen. Persistent scratching creates open wounds, providing entry points for opportunistic bacteria such as Staphylococcus aureus, which proliferate and produce purulent discharge.
Pathogen transmission occurs during the flea’s blood meal. Bartonella infection may remain subclinical but can progress to fever, lymphadenopathy, and ocular inflammation. Rickettsial organisms provoke vasculitis, leading to skin lesions and systemic signs. Mycoplasma infection compromises red blood cell integrity, aggravating anemia.
Tapeworm infestation follows ingestion of an infected flea. Adult worms reside in the small intestine, shedding proglottids that appear as rice‑like segments in feces. Clinical impact includes weight loss, abdominal pain, and occasional vomiting.
Overall, flea exposure compromises feline health through hematologic depletion, immune‑mediated skin disease, vector‑borne infections, and parasitic gastrointestinal disturbance. Prompt detection and effective ectoparasite control are essential to prevent these cumulative effects.