Control on the host animal

A.Washing the dog or cat with insecticides (for example shampoos containing pyrethrin I and II and piperonyl bubutoxid) kills the adult fleas that happen to be on the dog or cat while it is being washed. There is no residual effect that protects against the fleas that jump on to the pet after the treatment. Therefore, these methods only functions a supplements to another control methods.

B. Flea collars and pour-on medications work by depositing the insecticide into the fur of the pet. From there, it sprinkles onto the places where the animal is, and thereby also where the flea eggs, larvae, etc. are located. These control methods can often kill a small population of fleas, but they are also used as support other control methods of the pet’s surrounding environment. Flea collars and pour-on products are also used preventively.

C. Methoprene is an insect hormone. When injected into the fur of the dog or cat, it will prevent the newly laid eggs from hatching. If used on its own, this control method best serves to prevent flea infestation or to control very small flea infestations. This can also be used as a supplement to other control methods.


An English zoologist has estimated that a typical cat flea population includes about 5000 fleas at various stages of development: 25 adult fleas are on the dog or cat. In the surroundings – mainly in carpets and in the animal’s sleeping place – there are 500 adult fleas, 500 cocoons, 3000 larvae and 1000 eggs. Therefore, the surrounding environment must also be treated.

There are several different ways to control fleas on cats. Some are quite effective if you are thorough, while others work best in combination with others. Most flea control methods are combinations of the following methods.


Is your dog or cat scratching itself more than usual? Is it biting itself with its front teeth? Have you seen any fleas? Do the people who are in contact with the pets get itchy red bumps – especially at the ankles? Check for fleas in the pet.

Regular flea inspection. Look closely in the groin of the pet where fleas like to sit. Go through the fur by moving your hand against the direction of the hairs, so that the hairs separate, and you have a clear view of the skin. Look for black irregular pieces of dirt (flea droppings) in the fur. Also check the place where the pet sleeps.

Thorough flea inspection. Collect material from the skin and examine it under a microscope. The material can be obtained by combing and brushing the dog or cat or by vacuuming the fur with a handkerchief on the mouth piece of the vacuum cleaner. Look for adult fleas, flea larvae, eggs and excrement.

The flea excrement. Small, black particles that dissolve and turn red in water can be flea excrement. Flea excrement contains blood from the host animal. The blood can be determined by means of one of the test strips used for the detection of blood in urine. Shake a little dust from the pet’s fur or sleeping place into a glass of water. Dip the test strip in the water and read the results. Positive result for blood (hemoglobin) can be caused by several different things, but flea excrement is the most common cause. More importantly, a negative result almost certainly proves that the pet is not infested by fleas and that it has not been infested by fleas recently.

ِTraps can also be used for the detection of fleas in the home. However, the traps only attract adult fleas. Despite this, they are occasionally used to keep the flea infestation level down. Lighted candles in water dishes on the floor of houses have been used to trap fleas. The fleas are attracted by the warmth of the light and are then trapped on the surface of the water. During the middle Ages, people wore small patches of fur underneath their clothes. The fleas liked to crawl around in the fur. Occasionally, they shook the patch of fur vigorously, and the fleas fell off. Another personal flea trap was a hollow stick with holes in it. It was placed under clothing in warm places and the fleas crawled through the holes. Inside the hollow stick, there was another stick which was covered in honey. The fleas then stuck to the honey-covered stick.

Today, it is still o you can buy flea traps. It is basically a light source placed on the floor and the fleas jump onto a tray with adhesive paper. By examination of the adhesive paper, it is possible get an idea if there is a need for flea control, or if control of a flea control treatment has worked satisfactorily. Since only adult fleas are attracted to the trap, it is not as effective as the control methods, which work on all stages of fleas, but it may work as a supplement other control measures.

Dog fleas and cat fleas

Season for cat fleas in august

Fig. 62. Season for cat fleas in august.

The cat flea will happily bite people

The cat flea will happily bite people

The dog flea, Ctenocephalides canis and the cat flea, Ctenocephalides felis, belong to the flea species that bite humans in the absence of a more suitable host. The two flea species are similar.

Dog Flea was once fairly common, but today, the cat flea is more common. Cat fleas can live on both dogs and cats, while dogs’ fleas are never seen on cats. In actual practice, the pets are nearly almost infested by cat fleas, but if a dog has dog fleas, their biology and control are the same. Cat fleas are a relatively new problem. The increase in the number of inquiries about the species to the Danish National Pest Infestation Laboratory began in the late 1960s. Today, it is estimated that one third of all Danish dogs and cats are infested by fleas each year. It is not known why cat fleas have become so common in our parts of the world.

The number of pets has increased and at the same time, it has become increasingly common for the animals to have access to all rooms of the house. Another contributing factor is the increasingly common wall-to-wall carpeting. It is difficult to remove flea eggs and larva from the carpets just by cleaning them. From this perspective, the flea problem is a self-made problem.