How do fleas infect cats? - briefly
Fleas enter a cat’s body when adult insects or newly hatched larvae attach to the animal’s skin during grooming or contact with infested environments, then bite to feed on blood. Their saliva, which contains anticoagulants, facilitates feeding and can transmit pathogens.
How do fleas infect cats? - in detail
Fleas reach domestic cats primarily through direct contact with contaminated environments or other infested animals. Adult female fleas lay eggs on the host; the eggs fall off onto bedding, carpets, or outdoor surfaces. Once on the ground, eggs hatch into larvae that feed on organic debris and adult flea feces, developing into pupae that remain dormant until stimulated by vibrations, heat, or carbon dioxide.
The insects locate a cat by detecting body heat, carbon dioxide, and movement. Upon landing, a flea jumps onto the fur, uses its claws to secure itself, and inserts its mouthparts into the skin to draw blood. Feeding triggers the female to produce eggs within 24–48 hours, perpetuating the cycle.
Conditions that accelerate infestation include:
- Temperatures between 70 °F and 85 °F (21 °C–29 °C)
- Relative humidity above 50 %
- Access to outdoor areas frequented by wildlife or stray animals
- Presence of carpeting, rugs, or upholstered furniture that retain moisture and debris
During a blood meal, the flea injects saliva containing anticoagulants and allergens, which can cause irritation, dermatitis, or allergic reactions in the cat. After engorgement, the flea retreats to a protected site on the host to digest the blood and later lay eggs, completing the reproductive phase.
Effective management requires breaking the life cycle: regular vacuuming of floors and upholstery, laundering bedding at high temperatures, and applying veterinarian‑approved topical or oral ectoparasiticides. Environmental treatments, such as insect growth regulators, prevent larvae from maturing. Prompt intervention reduces the risk of secondary infections and limits the spread to other pets in the household.