How do dog fleas bite? - briefly
Fleas puncture the dog’s skin with needle‑like mouthparts called stylets, injecting saliva that contains anticoagulants to keep blood flowing while they feed. The bite appears as a small, itchy red spot where the insect has drawn a tiny amount of blood.
How do dog fleas bite? - in detail
Dog fleas locate a host by sensing heat, carbon‑dioxide, and movement. Once a suitable animal is detected, the flea jumps onto the skin and begins to explore the fur with its hind legs, using sensory receptors to find a thin area of skin.
The flea’s mouthparts consist of a hardened, needle‑like stylet and a flexible labrum. The stylet penetrates the epidermis at an angle that minimizes resistance. As the stylet advances, the flea injects saliva containing anticoagulants and enzymes that prevent clotting and break down tissue. This saliva also contains proteins that trigger the host’s immune response, producing the characteristic itchy welts.
Feeding proceeds in two phases:
- Initial probing: The flea inserts the stylet, releases saliva, and begins to draw blood through a thin canal formed by the labrum.
- Sustained ingestion: Blood flows into the flea’s foregut, where it is stored temporarily before digestion. An adult flea can ingest up to 15 times its body weight in blood within a few minutes.
During feeding, the flea remains attached by tiny claws that grip the hair shaft, allowing it to move forward or backward while maintaining contact. Bites are typically found on the lower abdomen, groin, and base of the tail, where the skin is thinner and less protected by fur.
After feeding, the flea retreats to a protected environment to digest the meal and reproduce. The saliva’s irritant compounds cause a localized allergic reaction in the host, leading to inflammation, redness, and scratching, which can result in secondary infections if left untreated.