Parasites that live on the outside of an animal (known as “ectoparasites”), are very common in Louisiana and frequently affect dogs and cats. Fleas, ticks, and mites are all ectoparasites but they have different effects on animal health. With temperatures rising, these parasites may reproduce at a faster rate and be even more of a problem. It is important that you know about several prevalent ectoparasites so you can protect your pet and yourself, as some ectoparasites can also bite humans and transmit diseases. Fortunately, these ectoparasites can be treated and prevented. That’s precisely what you’ll learn here!


The most prevalent flea on dogs and cats in North America is Ctenocephalides felis. These fleas lay eggs in a dog or cat’s coat, but these eggs easily fall off the animal’s fur and into the surrounding environment, including your home! Flea eggs and larvae can survive and develop in carpet fibers and in the cracks between hardwood floors. Mature fleas are blood-sucking ectoparasites, meaning they acquire blood from animals as their source of nutrition. After digesting blood from a dog or cat, the blood is excreted and dries into black fecal pellets known as ‘flea dirt’. This ‘flea dirt’ is commonly seen on animals that have fleas.

Fleas can have harmful effects on animals and people. A very heavy flea infestation can lead to anemia in cats and dogs. A common response to flea infestation is flea allergy dermatitis, which is characterized by inflammation, extremely itchy skin, and hair loss along the animal’s lumbosacral region, tail, thighs, and stomach. Humans can also experience an allergic reaction as a result of flea bites. Additionally, fleas are capable of transmitting several other pathogens, including Dipylidium caninum (tapeworms) and Bartonella hensalae (which causes ‘Cat Scratch Fever’ in humans). If you see small white segments resembling a grain of rice (Dipylidium caninum segments known as proglottids) in your pet’s feces or on its coat, your pet likely has fleas.

Because of the negative impact fleas can have on human and animal health, the Companion Animal Parasite Council recommends treating dogs and cats year-round and throughout their lives with flea control products. If an animal has fleas, all animals in the home should be treated with flea control products, and the home should be thoroughly cleaned to eliminate eggs and/or larvae from the environment. We recommend discussing a flea control and prevention program with your veterinarian, as there many flea control products available and he or she will create a treatment plan specifically for your pet’s needs.



Ticks are other blood-sucking ectoparasites that can have harmful effects on human and animal health. Many different tick species are present in North America, and those that affect dogs and cats include the Ixodidae (hard ticks) and Argasidae (soft ticks). Hard ticks are much more common in North America. After undergoing several life cycle stages to reach maturity, adult ticks feed on animals, significantly increasing in size as they consume blood. Ticks may cause inflammation and itching around the feeding site on the animal, as well as anemia from significant blood loss. The open feeding site may predispose the animal to secondary infections. One extreme consequence of tick infestation is tick paralysis. Tick paralysis is characterized by acute, flaccid motor paralysis due to a neurotoxin produced by females of several tick species, most commonly Dermacentor in the United States.

Ticks are found in many parts of the United States, with varied distribution of tick species in different areas. Many ticks live in the leaf litter associated with wooded areas frequented by wildlife, while others prefer grassy meadows, open woods, kennels, or vegetation near homes. To reduce the likelihood and number of ticks living near your home, cut grass closely, remove brush piles and leaf litter regularly, limit ground cover near your home, and select plants that do not attract deer or other wildlife. Prevent outdoor roaming of dogs by keeping them on a leash or inside a fenced area. In addition to managing pets and your home environment, chemical treatments are available for heavily infested areas.

Ticks can transmit a variety of diseases that affect both humans and animals. Several noteworthy diseases transmitted by ticks include Borrelia burgdorferi (Lyme disease), Babesia microti (Human babesiosis), and Anaplasma phagocytophilum (Anaplasmosis). Because of the potential adverse effects of tick infestation, the Companion Animal Parasite Council recommends treating dogs and cats year-round and throughout their life with tick control products. Ticks found attached to animals or humans should be removed immediately. The longer the tick is attached, the more pathogen-containing saliva is injected into the host. Smaller numbers of ticks can be manually removed by a veterinarian with forceps and proper protective equipment. Severe infestation may require more intensive chemical treatment followed by manual removal of the remaining ticks. We recommend discussing a tick control program with one of our veterinarians, who will create a treatment plan for your pet’s needs.



Mites are ectoparasites that tend to burrow in hair follicles or live on the surface of skin in the external ear of dogs and cats. Those that tend to burrow include Sarcoptes, Demodex, and Notoedres and contribute to a skin condition known as ‘mange’. Otodectes, often referred to as ear mites, reside on the skin in the external ear. All of these mites are very small, so your veterinarian will perform a skin scraping to identify burrowing mites under the microscope. An ear swab sample can be used to identify ear mites.

Otodectes ear mites can lead to dark brown buildup in the ear, ear scratching, and head shaking, with infection and rupture of the tympanic membrane occurring in more severe cases. Ear mites are easily treatable, and treatment should begin immediately.

Sarcoptes and Notoedres are small mites that burrow in hair follicles and cause a rapid onset of intense itching. Sarcoptes typically infest dogs and Notoedres prefer cats. These mites are highly contagious, cause hair loss and skin thickening, and can infest humans as well! Because of this, treatment with drugs approved for mange is recommended. Demodex can be localized or generalized, meaning it can affect a small portion of the animal or the entire body. Demodex mites have not been shown to infest people. Localized demodicosis is characterized by hair loss around the eyes, muzzle, face, and forelimbs. The skin may be red and flaky. The vast majority of cases of localized demodicosis occur in young animals, and will resolve on their own by the time puberty or 1 year of age is reached. Generalized demodicosis can lead to generalized hair loss, crusting, skin thickening and pigment changes, redness, itching, and pain. This is a serious problem that can lead to secondary skin infections, and immediate treatment is warranted. In general, treatment is not recommended for localized demodicosis, but aggressive treatment including miticide, antibiotic therapy, and evaluation of underlying disorders is needed for generalized demodicosis.

What to do


Fleas, ticks, and mites are ectoparasites that can have a negative impact on human and animal health. Now that you are educated on the basics behind these parasites, you can make responsible decisions about parasite control. If your pet is not currently being treated for parasite control, please call us and schedule your appointment. We’re here for you!