INTRODUCTION
Fleas play an important role in causing clinical skin disorders and diseases transmission in man
and pets animals (Rust & Dryden, 1997). Fleas are one of the most important ectoparasites with
more than 2,000 species worldwide affecting mammals, birds, and reptiles (Hsu, 2003). In some
locations, fleas represent over 50% of all the dermatological cases presented to small animal
clinics. Most are limited to hosts with nests as this can provide conditions for the completion of
their life cycle (Linardi & de Avelar, 2014). While fleas on pets are generally considered a
nuisance that may cause some dermatologic problems, they are also responsible for the
transmission of several important diseases in humans and animals (Dryden & Rust, 1994). They
have been involved in transmission of cat scratch disease (Bartonella henselae) (Chomel et al.,
2006; Comer et al., 2001), Rickettsia typhi (Murine thyphus), Rickettsia felis (Finkelstein et al.,
2002; Rolain et al., 2005), and also serve as the intermediate host for the tapeworm Dipylidium
caninum (Rust & Dryden, 1997) and several trypanosomatids (Coutinho & Linardi, 2007).
The term ‘‘cat flea,’’ which is the approved common name for Ctenocephalides felis felis (C. f
felis), can occasionally cause confusion. When it appears in print, it refers to the specific flea
genus and species and not to fleas recovered from cats. There are four recognized subspecies of
C. felis throughout the world: Ctenocephalides felis damarensis and C. felis strongylus occur
primarily in East Africa, C felis orientis occurs in India and Australia, and the widespread C. f
felis occurs in all continents except Antarctica and is the only subspecies that occurs in North
America (Rust & Dryden, 1997). The cat flea, C. felis, is a clinically important parasite of
domestic pets, being responsible for the production of allergic dermatitis, serving as the vector of
Introduction
2
various bacterial pathogens, and being the intermediate host for filarid and cestode parasites.
Flea allergy dermatitis is the most common dermatologic disease of dogs and a major cause of
feline miliary dermatitis (Dryden & Rust, 1994; Rust & Dryden, 1997).
Clinical features vary from asymptomatic to severe hypersensitivity reactions with restlessness,
alopecia from scratching and biting resulting in a pruritic papular dermatitis. Vacuuming of
carpets, furniture cushions, rugs, or other substrata, with a vacuum machine containing a ‘‘beater
bar,’’ will remove many of the flea eggs and larvae. In addition, cocooned pupae at the upper
levels of the carpet can also be affected. The vibration also stimulates adult fleas to emerge from
their cocoons so that they can be collected in the vacuum machine. Therefore frequent
vacuuming, during a flea infestation, can reduce the overall flea burden in the home. It should be
ensured that vacuum bags are disposed of properly, to prevent recolonization of the home with
flea stages previously removed by vacuuming. Because outdoor development of immature flea
life stages is limited to shaded areas, altering outdoor environments to eliminate such habitats
can effectively reduce flea populations. Because urban wildlife, such as opossums, raccoons, and
foxes, are good hosts for cat fleas, pet owners should avoid encouraging visitations by wildlife,
which will affect flea and tick control (see later discussion). Treatment of indoor and outdoor
environments with insecticides requires knowledge of what to use and where to use it. For this
reason, it is suggested that pet owners consult with a licensed pest control specialist for such
applications (Angelbeck-Schulze et al., 2014; Perrins & Hendricks, 2007).
In line with increasing urbanization over the last few decades, flea species that infest pets have
become household pests. Thus, and for reasons of animal and human welfare, the control of fleas
is of great importance worldwide. Despite the increase in the number of products available and
Introduction
3
their use, flea infestation of cats and dogs is still widespread in Europe and on other continents,
whereas resistance of these insects against many chemicals has been detected (El-Gazzar et al.,
1986). Cat fleas are the most important ectoparasite of cats and dogs worldwide. During the past
ten years, topical and oral applications of insecticides such as fipronil, imidacloprid, lufenuron
and, most recently, selamectin have revolutionized cat-flea control. Recent studies show that
these therapies eliminate the need to treat indoor and outdoor environments, and their use
markedly reduces the severity and prevalence of flea allergic dermatitis. Surveys have yet to
reveal the development of insecticide resistance to these chemical compounds. Extending the
longevity of these effective host-targeted therapies should be a major goal of the veterinary
community (Rust, 2005).