Parasitic diseases

Differences Between Fleas and Ticks

Cristina Pascual
By Cristina Pascual, Veterinaria. Updated: January 29, 2024
Differences Between Fleas and Ticks

Both fleas and ticks are external parasites belonging to the phylum Arthropoda. Both live on and feed from their host animal, causing stress, irritation, and different health problems. They also can parasitize various animal species, including birds, mammals, and reptiles. Knowing the differences between fleas and ticks is critical to your pet's health, so you can take preventative measures and provide them with the best care possible.

The following AnimalWised article explains the main differences between fleas and ticks, their main characteristics and the dangers they pose to our pets.

You may also be interested in: Tick Diseases in Dogs - Symptoms and Treatment
  1. Common characteristics between fleas and ticks
  2. Differences in the morphology of fleas and ticks
  3. Differences in the biological cycle of fleas and ticks
  4. Differences in host specificity of fleas and ticks
  5. Differences in treatment against fleas and ticks
  6. How to distinguish a flea from a tick?
  7. The importance of treatment for fleas and ticks

Common characteristics between fleas and ticks

As we have already mentioned, both fleas and ticks belong to the phylum Arthropoda. The fact that they are both arthropods means that they share a number of common physical characteristics:

  • They have a chitinous exoskeleton that is rigid in some places and elastic in others.

  • They have articulated limbs, some of which have specialized sensory organs and other structures.

  • Their exoskeleton consists of a cuticle, a noncellular material secreted by the epidermis.

  • Their exoskeleton cannot stretch and therefore restricts growth. Therefore, they replace their exoskeleton by molting or discard the old exoskeleton after growing a new one that has not yet hardened.

  • They both have a highly developed visual system that includes both compound eyes.

  • Both parasites are wingless.

Additionally, both fleas and ticks are parasites because they need to feed and protect themselves. Thus, they began to colonize higher organisms (birds, mammals, and reptiles) and became hematophagous ectoparasites. They both prefer animals that have hair, because it serves as protection and shelter.

In order to adapt to parasitism, they had to develop binding organs that allowed them to stay on their hosts and feed on their blood. In the case of fleas, they have evolved lacinia, jaws with which they can pierce the skin of their host. Ticks have evolved the hypostome, a club-shaped mouthpiece with backward-facing hooks that prevent them from detaching from their hosts' skin.

Continue reading this other article if you want to learn more about other animals and insects with an exoskeleton.

Differences in the morphology of fleas and ticks


Fleas are insects, or more precisely, they are parasitic insects. As with all insects, their body is divided into three segments: head, thorax and abdomen.

  • The head consists of the antennae and the mouthparts, which are used for feeding.

  • Three pairs of legs emerge from the thorax. The third pair is particularly strongly developed, which gives them a great jumping power of up to 30 cm.

  • The abdomen contains the reproductive organs, which are copulatory organs in males and laying organs in females.

Although fleas are insects, they do not have wings, having lost them during their development.


Ticks, also known as ixodid ticks, are small arachnids. The body of adults is divided into two segments: the gnathosoma and the idiosoma.

  • The gnathosoma is the mouth apparatus: it contains a series of appendages (chelicerae and palps) for feeding.

  • The idiosoma forms the rest of the body and contains the locomotor apparatus (4 pairs of legs) and the reproductive apparatus (bulbs or copulatory suckers in males and the genital organ in females). Unlike fleas, ticks cannot jump.

If you want to learn more facts about ticks and fleas, do not miss the following articles where we describe their life cycle in more detail:

Differences in the biological cycle of fleas and ticks

Another important difference between fleas and ticks is their biological cycle.


Fleas are holometabolous insects, which means they go through a complete metamorphosis. Their biological cycle goes through the stages of egg, larva, pupa, and adult. The adult females lay their eggs on the parasitized animal, which fall to the ground after a few hours. The eggs then hatch into larvae, which develop into pupae. Eventually, they metamorphose into adults that parasitize new hosts. It should be noted that only adult fleas are hematophagous and parasitic.


In contrast, ticks go through four developmental stages: eggs, larvae, nymphs, and adults. The gravid female lays the egg on the ground, from which a larva hatches and climbs onto the host. Depending on the tick genus, the different stages may develop in the same host or in different hosts, which in turn may or may not belong to the same species.

Regardless of the number of hosts involved in the biological cycle, after fertilization, females drop to the ground to lay their eggs and the biological cycle is complete. This means that ticks can be parasites in all their developmental stages.

Differences Between Fleas and Ticks - Differences in the biological cycle of fleas and ticks

Differences in host specificity of fleas and ticks


Fleas are non-host-specific parasites, which means that the same species of flea can parasitize different species of animals. The main flea species that parasitize our pets are Ctenocephalides felis, Ctenocephalides canis, Pulex irritans and Echidnophaga gallinacea.


The host specificity of ticks is also low, although slightly higher than fleas. The following are the major tick families and genera that parasitize our pets:

  • Family Ixodidae: They are called hard ticks because they have a dorsal shield that covers the entire back in males and only a portion in females.
  • Family Argasidae: They are called soft ticks because they do not have a dorsal shield. The most important genera are the genus Ornithodoros (parasitizes mammals and is responsible for the transmission of the African swine fever) and the genus Argas (parasitizes birds).
  • Genus Dermannysus: It is a parasite of birds, but can also parasitize humans. They are characterized by a reddish color because they feed on blood.
  • Genus Varroa: parasitizes bees, especially bee larvae, in the cell.

Differences in treatment against fleas and ticks


In case of flea infestation, both the environment and the animals must be treated:

  • Environment: If we suspect that we have fleas in our home, it is important to act quickly and effectively. We must vacuum all corners of the house (carpets, upholstered furniture, etc.) and wash all textiles (clothes, bedding, etc.) at high temperature (60 °C). This must be followed by treatment with insecticidal powders, aerosols, or sprays.

  • Animals: Animals should be treated with an adulticide and an IGR (Insect Growth Regulator). The adulticide acts on the adult parasites, while the IGR inhibits flea chitin development, disrupting the cycle and preventing flea development.


In case of tick infestation, treatment can be done with different strategies:

  • Chemical control by acaricidal drugs: there are different active ingredients effective against ticks (pyrethrins, phenylpyrazoles, macrocyclic lactones and isoxazolines) and different forms of application (pipettes, collars, baths, infusions, etc.). The active ingredient and the method of administration are selected according to the animal species.

  • Biological control: consists of the use of bacteria, fungi and nematodes, as they are natural enemies of ticks. They are effective against eggs, larvae, and adults.

  • Vaccines: although most are still in the experimental phase, some vaccines are already available to treat tick infestations, such as the vaccine against Boophilus microplus, which parasitizes cattle.

How to distinguish a flea from a tick?

If you find an external parasite in your pet's fur but do not know if it is a flea or a tick, consider the following points:

  • Morphology: there are important differences between the two types of parasites. Fleas have a laterally flattened body and three pairs of legs, as they are insects. In contrast, ticks have a ventrally flattened body and four pairs of legs because they are arachnids.

  • Size: Fleas are between 1.5 and 3 mm long. Before feeding, ticks are usually about 3 mm, but after feeding they can grow up to 1 cm long.

  • Jumping: fleas have the ability to jump long distances, which ticks are not able to do. So if you see tiny parasites jumping through your pet's fur, it probably has a flea infestation. On the other hand, if you find a parasite sticking to your pet's skin, it is probably a tick.

  • Developmental stages: with fleas, only the adults are parasites, while with ticks, any developmental stage can be a parasite. So if you have a tick infestation, you can find anything from larvae and nymphs to adults.

  • Your pet's skin: even if we do not see the parasites in our pet's hair, we can suspect a flea infestation if we find feces on their skin. To do this, we just need to moisten a cotton ball with water and swipe it over your pet's hair. In this way, the remains of digested blood will stick to the absorbent cotton.

If you suspect your cat or dog is infested with ticks or fleas, see your veterinarian immediately to determine the best course of action based on your pet's age, physical condition and environment. Delaying treatment can have serious consequences for your pet's health, which we will discuss in the following section.

Vinegar is an effective method for eliminating fleas from dogs with mild to moderate infestations. Continue reading this other article to learn how to treat an infestation of fleas and ticks with vinegar.

The importance of treatment for fleas and ticks

Domestic and wild animals should be protected from fleas and ticks, because:

  1. They have a direct pathogenic effect. Their bites cause primary lesions such as wheals or micro abscesses, which are used by flies to lay eggs and can cause infections. They can also cause secondary lesions such as alopecia, erythema, seborrhea, and pyoderma. In the chronic phase, hyperkeratosis, lichenification and hyperpigmentation of the skin may occur. Also, because they are hematophagous, they can cause significant anemia in heavily parasitized animals.

  2. They can cause allergic reactions, as in the case of flea bite allergy dermatitis (DAPP), which affects dogs and cats. As a result of an allergic reaction to an allergen in flea saliva, they cause severe itching. In cats, flea bites can also trigger an allergic process called eosinophilic granuloma.

  3. They can act as carriers of bacteria, viruses, and parasites. Because they are hematophagous arthropods, they can transmit pathogens from one animal to another through their blood supply. Ticks can transmit pathogens such as Ehrlichia, Anaplasma, Rickettsia, Borrelia, Flavivirus, or Babesia. Fleas can transmit pathogens such as Bartonella, Rickettsia, Poxvirus, Dipylidium, and Acanthocheilonema. To humans, they can also transmit some very important human diseases such as Lyme disease and tularemia, among many others.

If you want to learn more about the consequences that fleas and ticks can have on your pet, continue reading this other article where we explain the effects of ticks on dogs.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Differences Between Fleas and Ticks, we recommend you visit our Parasitic diseases category.

  • Lamb, M., Red, F.A. (2000). Veterinary Parasitology. McGraw-Hill Interamericana of Spain.
  • Galvez, R., Miró, G. (2016). Influence of climate on the presence of fleas in pets. Faculty of Veterinary Medicine, Complutense University of Madrid.
  • Lloria, M.T. (2002). ticks Animal parasites . Elsevier. professional pharmacy; 15(5):73-77.
Write a comment
Add an image
Click to attach a photo related to your comment
What did you think of this article?
1 of 2
Differences Between Fleas and Ticks