We will focus here on the dog sucking louse (Linognathus setosus)!

About 400 species of animal biting/sucking lice are known, among them the dog sucking louse. Central Europe is the home of roughly 20 species. In all, though, over 3,000 species of animal lice are recognized, with 650 to 1,000 of them being found in Central Europe.

A dog sucking louse is a wingless parasite with a yellowish brown oblate body. After it sucks blood, its abdomen turns dark brown. It has a triangular head that is narrower than the thorax. Lice have sharp mouthparts, a 5-joint antenna, and strong claws on their feet.

This bloodsucking louse is not very mobile, but sucks blood daily from different spots. The irritation from the bite causes a skin reaction and severe itchiness, with the result that the dog is restless and scratches itself incessantly. The relatively high amount of blood loss from a heavy infestation can adversely affect the dog’s health. The saliva of a louse may also trigger an allergic reaction.

A female dog sucking louse is 1.6-2.5 x 0.9 mm in size, while the male louse is about 1.5-2 x 0.7 mm in size. The larvae are somewhat smaller, while the eggs (nits) are oval and about 1-1.1 x 0.5-0.6 mm in size.

These parasites are largely host-specific, which means they are bound to their host for life.

Life cycle of lice:

The Linognathus setosus develops entirely on the body of its host, over a period of 2-4 weeks. For 4-6 weeks, females lay 5-10 nits daily that stick to the host’s hair with a waterproof glue. The females die soon afterwards.

Larvae begin to hatch in 5-10 days, and immediately start sucking blood. They go through three nymphal stages, each ending with a molting. Disengaged from the host, a dog sucking louse can survive only for a few days.


Lice are transmitted by direct contact from one animal to another. Hence, transmission by combing or brushing is rare. In most cases, lice infest animals that live in unhygienic conditions and are generally very weak, very young, abandoned, neglected, and have a matted coat.


An infestation means you can either see the little dark spots moving on the skin or white nits of the lice sticking to hair shafts near the skin. Infested animals scratch and bite themselves.

Take your dog to a vet, if it seems to scratch itself very often. A vet will examine the dog and determine the cause.

Direct harm:

The bites, bloodsucking, and the saliva of the lice cause severe itchiness in a dog.


Skin reactions like papules and the louse’s saliva on the skin cause severe itchiness. Lice prefer to infest the head of a dog, in particular its upper lip, ears, eyelids, throat, and breast. However, they do attack the flank and back also.

The animal may develop an allergic reaction that leads to severe itchiness. The dog becomes restless and bites and scratches itself. The relatively amount of blood loss from a heavy infestation can also emaciate the dog.

Secondary inflammation:

The skin lesions from biting and scratching may lead to secondary infections, and the dog may also suffer from pain and fever.

Indirect harm:

Tapeworms - Dipylidium caninum:

Your dog may be infested with this species called the cucumber or double-pored tapeworm, if it has nipped infected lice harboring the worm’s larvae. These intestinal parasites reach a length of 50-80 cm and are prevalent along our latitudes. They are absolutely harmless for humans. The shape of Dipylidium caninum reminds one of cucumber or pumpkin seeds – hence the common name.

Transmission to humans:

Humans can also be infested by lice.


Under close examination, lice or their eggs (nits) can be indentified in the animal’s coat.


You need insecticides to kill lice, preferably applied thoroughly as a bath or spray/dust. Repeat the treatment after one to two weeks, because the chemicals are not effective enough on the nits, and retreatment will kill any lice that have hatched in the meantime. Also treat all dogs that have come in contact with the infected one.

It is not necessary to treat all the areas where the dog lives, just clean the dog’s sleeping basket and bedding.

How you can avoid lice:

Keep your dog away from infected animals!

The most effective way to prevent your dog from getting lice or other ectoparasites is to take proper preventive measures and use modern topical spot-on ointments or a medicated collar. The topical medication penetrates the skin and spreads across the entire surface of the body. These medications are stored in the skin and protect the canine for 4-6 weeks. They also function as repellants by warding off the parasites such that they leave the animal.

Your vet will naturally guide you on taking the necessary preventive measures.


The author has exercised his best knowledge and belief when writing the above articles and content, which are purely for purposes of providing information for visitors. The content of the Web site www.familial-shar-pei-fever.de does not replace professional diagnostics, advice, and treatment by a vet. The information is presented here as accurately as possible and in good faith and trust in the professional integrity of the sources. The author of this site has not evaluated the statements about products and health conditions, whereby any details of diagnostics, therapies, and medications are not intended as recommendations of any kind whatsoever. Never give your dog any medicines or medicinal herbs without consulting your vet. Since the author is not a qualified medical practitioner or vet, he does not accept any liability whatsoever for providing the information herein.

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