What do fleas and lice look like on dogs? - briefly
Fleas appear as tiny, brown‑black, laterally compressed insects that move quickly by jumping; lice are small, pale‑gray, flat‑bodied parasites that cling to hair shafts and crawl slowly.
What do fleas and lice look like on dogs? - in detail
Fleas are small, laterally flattened insects measuring 1 – 3 mm in length. Their bodies are dark brown to reddish‑black, covered with short spines that give a rough texture. Under magnification, the abdomen appears segmented, and the hind legs are enlarged for jumping. On a dog’s coat, fleas are most often seen moving rapidly, especially around the neck, base of the tail, and inner thighs. Their presence may be confirmed by the presence of tiny black specks (flea feces) and a characteristic “sand”‑like odor.
Lice are obligate ectoparasites, considerably larger than fleas, ranging from 2 to 5 mm. They have a flattened, elongated body, usually grayish‑white to tan, with a smooth, glossy surface. Unlike fleas, lice lack jumping legs; all six legs are adapted for walking and clinging to hair shafts. Two main types affect dogs:
• Chewing lice (Trichodectes canis) – visible as small, oval insects moving slowly through the fur, often concentrated on the head, ears, and forelimbs. Their mouthparts are adapted for feeding on skin debris rather than blood.
• Sucking lice (Linognathus setosus) – similar in size but darker, found primarily on the neck, shoulders, and abdomen. They attach to the skin with specialized claws and feed on blood, leaving small, pale, raised lesions.
Both parasites can be identified without magnification by their distinct movement patterns: fleas jump erratically, while lice crawl methodically. Visual inspection of the coat for live insects, nits attached to hair shafts, and accompanying skin irritation provides reliable diagnosis.