Can fleas kill a dog?

Fleas are common ectoparasites that appear on dogs, especially in hot weather. What health problems can the flea lead to the dog? Can a flea kill a dog? To answer these questions this post will talk about the relationship between fleas and dogs. In addition, we will talk about ways to prevent and control this type of pest.

Can fleas kill a dog?

Fleas themselves will not kill the dog but in case of infestation and lack of care they can lead to the death of dogs. In general, fleas will lead to itching and discomfort for dogs. These annoyances can lead to stresses that can immunosuppress the dogs. Thus, favoring the appearance of diseases that can end up resulting in the death of the dog.

To avoid the dog’s death, the animal must be properly treated, and the environment must be controlled, preventing flea proliferation. Dogs can bring fleas from street walks, but humans can also be a form of transmission, as fleas can get on clothes, shoes and even objects of humans being carried from one environment to another.

What are fleas?

Fleas are considered ectoparasites that feed on the dog’s blood. The flea can bring several harms to the dog’s health and therefore it must be avoided with preventive actions that reduce the chances of the animal having contact with this type of parasite.

Main diseases caused by fleas

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 prevent and control fleas?

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.


Fleas can cause serious health problems to dogs and when not treated correctly can be the gateway to other infectious diseases and pathologies that can result in animal death. That’s why a well-kept environment and an animal protected from fleas is ideal. If the animal is infested with fleas or has a significant deterioration in health, it is advisable to consult a veterinarian.

Frequently Asked Questions (FAQs): Can fleas kill a 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.

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