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Nathalie Sari - Tiertraining & Verhaltensberatung

This article was written by TOBALIE in cooperation with Nathalie Sari - Tiertraining & Verhaltensberatung

If your beloved four-legged friend often scratches, shakes and gnaws at himself, it is possible that he has caught fleas. In the case of a heavy infestation, the dog can’t stop scratching and – not so seldom – even inflicts wounds on itself. This is an enormous torment for our beloved dogs. You can learn everything about fleas in dogs in this article. Have fun reading and learning!

What are fleas?

One thing is quite clear: fleas are annoying, unwelcome and persistent. But what exactly are fleas? They are insects, or more precisely, parasites. Parasites are characterised by the fact that they infest a so-called host and feed on its body fluids – usually blood. They lay eggs on their hosts and multiply rapidly.

Fleas do not have wings, but they have an enormous jumping power, up to one metre. They also have a biting and sucking proboscis, as well as bristles and claws on their legs, with which they are able to claw excellently into the hair coat. 

The life cycle of the dog flea

  1. The flea eggs usually make up the largest part of the infestation. A female flea can lay about 50 eggs a day directly on the dog. Since many of them fall off, they are found everywhere your dog is. 
  2. Flea larvae like to stay in textiles and crevices in the floor.
  3. Flea pupae are protected in their cocoon and can survive for months. 
  4. The flea itself plays only a small part in the infestation, but constantly produces offspring. 

How do I recognise fleas on dogs?

Fleas are tiny, only 4mm in size, at least those that have a preference for dogs. So it is quite difficult to spot them with the naked eye. The first signs can be seen in the dog’s behaviour:

  • He scratches like crazy. The intensity increases over time.
  • He suddenly turns around and bites himself.
  • He gnaws on certain parts of his body.
  • He shakes himself frequently.
  • Visible redness, puncture marks (often several in a row), inflammation.
  • Dull coat.
  • Allergic reactions and hair loss in affected areas may be possible.
  • Restlessness, nervousness.

Another way to detect fleas in dogs is to brush the coat with a special flea comb. Either the fleas themselves are on the comb or their excrement. Look for small black balls and rub them into a wet paper towel or white handkerchief. If these balls turn reddish-brown, your pet is most likely infested with fleas.

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How dangerous is a flea infestation for the dog?

Many people underestimate the possible health risks. Not only does your darling suffer from the excruciating itch, allergic reactions and bacterial infections can also develop. Mostly triggered by saliva and scratching. 

If the infestation is very severe, blood and iron deficiency can also occur, weakening your pet considerably. Particular care should be taken with puppies, sick or older animals. 

Serious skin damage can also occur. In addition, these pests can also transmit certain pathogens and other parasites, such as spotted fever, meningitis and the voracious tapeworm

An infestation should therefore be taken very seriously and treated medically immediately. Don’t forget that your living space is also infested with these little animals and their eggs, good hygiene and certain room sprays are then used.

Important: If you suspect a flea infestation, consult a veterinarian immediately! 

Can fleas be transmitted to humans?

In and of themselves, fleas have a certain preference when it comes to their hosts. There are about 2400 species worldwide, each of which prefers a different species. Some species can grow up to 9mm in size. It makes you shiver just reading about it, doesn’t it?

A dog flea has a particular weakness for dogs, but is not solely dependent on the dog. 

On the contrary, fleas feel most comfortable in their various nests. This can be your pet’s blanket, but unfortunately also your head cushion. They spend most of their time in these nests and then seek out a host to “eat”. If one of these nests is closer to you than to your dog, it can happen that the dog flea also bites you.

If you are also affected, seek medical help. Certain pathogens, as described above, can also be dangerous for you.

Fighting fleas on dogs

Spot on preparations have proven to be effective. These are dripped onto the dog’s skin and work for about four weeks. After three to four weeks at the latest, the product should be reapplied to finally control the fleas in the dog before the newly hatched fleas lay eggs. 

However, not every dog tolerates these preparations. Since there are a variety of treatment options, ask your veterinarian for advice on which method is best for your pet.

It is also important to treat the surrounding area, otherwise the dog will constantly be reinfected. 

Where do dogs get fleas?

Basically, it is possible for your dog to catch fleas anywhere and at any time. All it takes is for your best friend to roll around in an infested area or play with other (infested) dogs. 

Fleas like to stay warm, so it is more risky to bring them home in the warmer seasons. But even in winter, they are happy about heated living spaces and can continue to reproduce without any problems.

How long is a flea-infested dog contagious?

Provided you have taken your dog to a veterinary clinic or similar and he has received a special treatment, usually an antiparasitic, and you have also cleaned your living space, it will take at least 24 hours for all the fleas to be dead. However, it often takes further treatments to break the flea cycle. This is because the new generation of fleas hatches from the eggs after about 3 weeks, and then you have to repeat the treatment before they start reproducing. 



A flea is an annoying and persistent bloodsucker that rarely comes alone. An infestation with these parasites is not only particularly distressing for your dog, but can also lead to serious health problems. Medical treatment must be initiated immediately and never forget your living space when combating them.