Trichodectes canis

Trichodectes canis
Class	Insecta
Order	Phthiraptera
Family	Trichodectodae
Species	Trichodectes canis

Also known as: Dog biting louse

Introduction

Trichodectes canis is a chewing louse of dogs. It is very host-specific and cannot infest any other species than the dog.

It can have serious effects in puppies and older, debilitated animals.

T. canis can also act as an intermediate for the tapeworm Dipylidium caninum.

The lice are transferred by direct contact between animals, or via shared combs and brushes.

Identification

The adults are small, yellow lice, measuring around 1.5mm in length. The head is broader than long and the antennae are three-segmented, short and exposed. The legs are stout and their tarsi bear single claws, with which they tightly grasp the hair of the host. The abdomen has 6 pairs of spiracles on segments 2 to 6 and many rows of large, thick setae.

Life Cycle

The female is capable of laying several eggs per day for approximately 30 days. The eggs then take around 7-14 days to hatch, and then give rise to three nymphal stages. The nymphs mature into reproductive adults within about 2 weeks.

The egg-to-adult life cycle requires about 30 to 40 days.

Clinical signs

It is more commonly found on the head, neck and tail attached to the base of the hairs.

Lice often congregate around body openings or wounds, seeking moisture.

Typical signs of infestation include: intense pruritus, scratching, biting, sleeplessness, nervousness and a matted coat.

Damage to the skin results in inflammation, excoriation, alopecia and secondary bacterial involvement.

Diagnosis

Diagnosis is made on the basis of clinical signs and identification of lice in the coat. This can be done by collecting tape strips or coat brushings which are examined under the microscope.

Treatment

Lice spend their entire life-cycle on the host and are readily killed by permethrin, carbaryl and fipronil.

These antiparasitics should be applied twice, 14 days apart.

References

Wall, R. (2001) Veterinary ectoparasites: biology, pathology and control John Wiley and Sons

Wall, R. (1997) Veterinary entomology Springer

Trichodectes canis Learning Resources
Vetstream To reach the Vetstream content, please select	Canis, Felis, Lapis or Equis
Literature Search Search for recent publications via CAB Abstract (CABI log in required)	Trichodectes canis publications

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