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Learn more about flea infestations, flea saliva allergy, and flea control.

Precisely because pet fleas have changed their way of life, they have become “culture followers”. They are now present all year round and also live quietly and unrecognized in many apartments. The pet owner has little choice but to protect themselves against fleas all year round. Appropriate preparations offer protection for up to three months – simple and non-toxic.

Flea saliva allergy

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Flea saliva allergy is a year-round allergic skin disease caused by the saliva of fleas, mostly affecting dogs and cats. The main symptom is severe itching, which can lead to self-inflicted severe skin changes and secondary infections.

A single bite can cause itching in an allergic animal for 4 weeks.

The main symptom of flea saliva allergy in dogs is intense itching, especially in the loin, groin and tail areas. Small papules appear as the first skin changes. Occasionally there is swelling of the popliteal lymph nodes. As a result of gnawing and licking, further skin changes such as erosions and crusts, so-called “hot spots” develop: circumscribed, superficial purulent skin inflammation. Additional overgrowth of the skin with yeast fungi can also occur. If a flea saliva allergy is chronic, hair loss, hyperpigmentation and thickening of the skin occur.

In cats, the clinical picture is more variable. The root of the tail and the lumbar, abdominal and groin regions as well as the neck are particularly affected. In addition to itching, the main manifestation is skin inflammation with papules and crusts the size of millet grains (miliary dermatitis). Hypersensitivity of the back can also indicate a flea saliva allergy. If it persists for a long time, patchy or bilaterally symmetrical hair loss can occur. Intensive licking can cause a flat, raised reddening of the skin (eosinophilic plaque). A non-painful lip ulcer can also occur. In cats, a flea saliva allergy can also be associated with lymph node swelling and cannot always be clinically distinguished from non-allergic dermatitis after flea exposure.

The life cycle of fleas

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Adult fleas spend most of their time on their host animal and also lay their eggs there. The eggs fall to the ground, the larvae hatch and crawl into dark regions (under furniture, deep in the carpet) where they pupate. Under suitable conditions, the adult fleas hatch from these pupae. A propagation cycle lasts 4 – 5 weeks. An adult flea can live on a host animal for 100 days and lay an average of 25 eggs each day.


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If you see a flea on your animal, there are already at least 100 eggs around the animal. If there is only a suspicion of flea infestation, the animal is combed with a fine-toothed comb and the hair from the comb is placed on a moistened sheet of white paper. If small black crumbs can be seen here, which turn reddish on the paper, it is flea excrement. Fleas themselves are usually only seen in severe infestations. Another indication is the detection of cucumber seed tapeworm eggs in the faeces, as this requires fleas as an intermediate host.

Sometimes neither fleas nor flea excrement can be found because the animals clean themselves particularly thoroughly due to the itching.


The best therapy is consistent flea control. This can be achieved through regular use of long-acting insecticides. We will advise you which preparation is best suited for your animal. The animals must not be bathed for up to two days after application so that the preparations can take effect. This flea control should be repeated consistently throughout the year.

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If an infestation is detected, the area around the animal should also be treated, especially the berth and preferred locations, since fleas are not permanently present on the animal and the effectiveness of the active ingredients applied to the animal is limited to this part of the flea population. Environmental treatment is through regular vacuuming and washing of blankets and carpets, aided by chemical flea control with environmental sprays. It often makes sense to repeat the treatment after 2-4 weeks to reach all stages of the fleas.