Found one flea on dog

Did you find a flea on the dog? What harm can fleas do to dogs? Is it normal for a dog to have fleas? Many owners who have dogs for the first time may not be used to the ectoparasite infestation in dogs. So, this post will talk about fleas in dogs and how to prevent and avoid infestation in these animals.

Found one flea on dog

If you have found one flea on your dog, be prepared! Because the environment in which the animal lives must probably have much more than one flea. Fleas are considered ectoparasites that feed on the dog’s blood. The flea can bring several harms to the dogs health and therefore it must be avoided with preventive actions that reduce the chances of the animal having contact with this type of parasite.

The flea cycle

The flea can present a life cycle in which the insect spends time on the dog and in some stages the flea is in the environment. The complete flea cycle can take up to 2 weeks to complete.

The adult flea is always on the dog, to feed and reproduce. So, the female fleas go to the environment where they lay their eggs. Flea’s eggs can be found on beds and in places where the dog usually spends most of their time, such as couches, beds and rugs.

The eggs hatch and give rise to larvae that feed in the environment until they become pulps and these pulps become adult fleas. Adult fleas search of a dog to feed on blood, thus restarting the cycle.

Importance of fleas for dog health

Fleas can bring many harms to dogs, among them we will talk:

  • Dog stress and wounds;
  • Canine dermatitis;
  • Allergic dermatitis to flea bites;
  • Worms.

Dog stress and wounds

When fleas walk on the dog’s back, they can cause the animals to scratch themselves, so excessive itching can cause the dogs to end up injuring themselves from scratching too much. These wounds can be treated, but if the animal continues to have fleas, it will continue to scratch.

The stress caused by excessive itching can lead to a change in the dog’s behavior in addition to leading to a reduction in the dog’s immunity, thus favoring the appearance of other diseases and even opportunistic diseases.

Canine dermatitis

The skin is the body’s natural barrier that is in balance with its typical microbiota. When any type of stress alters the integrity of this tissue, it can lead to the proliferation of scabies, bacteria and even fungi resulting in dermatitis.

Stress to the skin caused by the itching of the dog with fleas or by the lesion generated at the site of the flea bite can be predisposing factors for the appearance of dermatitis. Beside fleas the skin is injured, thus altering the integrity and local immunity.

Dermatitis must be treated according to the specific parasite causing the disease, and therefore a veterinarian must be consulted. However, if the animal continues to present fleas, it will probably present all the dermatitis again. Therefore, treatment of both dermatitis and fleas is necessary.

Allergic flea bite dermatitis

Some dogs are allergic to flea drools. When the flea is feeding on the dog it releases anticoagulant and anesthetic secretions. This drool can lead to a generalized reaction in the dog that has an allergy. So, dogs can have alopecia and itching in various regions of the body.

Flea bite dermatitis is treated with oral and even topical anti-allergy medications. In addition, all fleas from animals and the environment must be eliminated. Currently, there are repellent collars, topical repellents and periodic medications that can prevent flea contact and infestation in dogs.


Some fleas can carry a worm called Dipylidium caninum. This worm is transmitted when the flea feeds on the dog’s blood. Dipylidium travels through the bloodstream and lodges in the gastrointestinal tract.

This worm when left untreated can lead to abdominal discomfort and perianal itching that results in the dog dragging its butt on the floor to scratch. In addition, this worm associated with a flea infestation can cause dogs to have anemia.

Treatment involves getting rid of fleas from the animal and the environment, and worm remedies can also be used. Animals with contaminated fleas can transmit to other healthy animals, so contact with other dogs should be avoided if the animal has fleas.

How to get rid of fleas on dogs?

Fleas can be eliminated by drugs that can be ingested, such as drugs that kill fleas due to the concentration of the drug in the dog’s blood. So, when ingesting the blood with the medicine the fleas end up dying. Usually, these medications can stay in the dog’s circulation for 30 and even 90 days, thus protecting the animal from new infections.

Spray medicines, powders, shampoos, and creams can also be used. This type of repellent should be used with caution because many of them can lead to dog intoxication when ingested by the animal. 

Some of these products can protect the animal for a few days, while others will take effect immediately and after washing the dog’s hair, the medicine loses its effectiveness, leaving the animal predisposed to new infections.

In addition, there are repellent collars on the market today, these collars can help repel ticks, fleas and even some flies. Repellent collars can have a longer effect, from 4 to 6 months. They are excellent ways to prevent dogs from coming into contact with fleas.

The environment must also be treated as most of the flea cycle takes place there. Therefore, chemical products can be used to kill fleas. In addition, it is important to wash the dogs beds, towels, bedspreads and sheets on which the animal is used to lying down. In this way, flea control can be done avoiding the dog’s infestation.


Dogs that have fleas can indicate a big problem for their owners. Dogs with fleas can be predisposed to a variety of diseases. That’s why it’s not normal for a dog to have fleas, so control and prevention is necessary so that the dog doesn’t get sick. Knowledge of the flea cycle shows us that most of the cycle takes place in the environment, so it is necessary, in addition to treating the dog, to clean and disinfect the environment.

Frequently Asked Questions (FAQs): Found one flea on dog

How do animals catch fleas?

Dogs can get fleas when they come into contact with other infected animals, environments or objects. Dogs can usually acquire fleas on walks or places with a lot of dog crowds.

What makes fleas appear?

Fleas can appear on infected animals or even humans as these insects can stick to a visitor’s clothing or skin. Dogs can be contaminated on the streets, in day care, hotels and even in veterinary clinics.

Where do fleas live in the environment?

You’ll find them anywhere and everywhere the dog frequents such as on blankets, beds, carriers, sofas, chairs, carpet, cracks or crevices in the floor and corners.


Fernandes, F. B. (2014). Controle de Ctenocephalides spp. em cães com dermatite alérgica à picada de pulga.

Picture from