Dog Flea

*Ctenocephalides canis* closely resembles the cat flea and is routinely misidentified as it; in North America it is genuinely uncommon, and confirmed records usually come from dogs with outdoor or kennel exposure. Adults are 1–4 mm, reddish-brown and laterally compressed, separated from the cat flea by a more rounded (rather than sloped) head, a shorter first genal spine, and eight rather than seven notches on the hind tibia — differences that require magnification. The life cycle mirrors the cat flea: egg, three larval instars, cocooned pupa, adult, completed in three to four weeks under warm humid conditions.

Adults feed frequently on canid hosts and remain on the animal, while eggs drop into kennel bedding, run surfaces, and soil. Larvae feed on adult flea faeces and organic debris in shaded, humid substrate. The species is a competent intermediate host of *Dipylidium caninum* and can transmit *Dipetalonema reconditum*; heavy infestations on puppies cause measurable anaemia. Bites on people are the same intensely itchy ankle-level papules produced by the cat flea, and flea allergy dermatitis in sensitised dogs is the more serious clinical outcome.