Abdullah S, Helps C, Tasker S, Newbury H, Wall R. Pathogens in fleas collected from cats and dogs: distribution and prevalence in the UK. Parasit Vectors.. 2019; 12:(1)

Beck S, Schreiber C, Schein E, Krücken J, Baldermann C, Pachnicke S, von Samson-Himmelstjerna G, Kohn B. Tick infestation and prophylaxis of dogs in northeastern Germany: A prospective study. Ticks Tick Borne Dis.. 2014; 5:(3)336-342

Beugnet F, Franc M. Results of a European multicentric field efficacy study of fipronil-(S) methoprene combination on flea infestation of dogs and cats during 2009 summer. Parasite.. 2010; 17:(4)337-342

Beugnet F, Franc M. Insecticide and acaricide molecules and/or combinations to prevent pet infestation by ectoparasites. Trends Parasitol.. 2012; 28:(7)267-279

Beugnet F, Porphyre T, Sabatier P, Chalvet-Monfray K. Use of a mathematical model to study the dynamics of Ctenocephalides felis populations in the home environment and the impact of various control measures. Parasite.. 2004; 11:(4)387-399

Beugnet F, Fourie J, Chalvet-Monfray K. Comparative efficacy on dogs of a single topical treatment with fipronil/(S)-methoprene or weekly physiological hygiene shampoos against Ctenocephalides felis in a simulated flea-infested environment. Parasite.. 2012; 19:(2)153-158

Blagburn BL, Dryden MW. Biology, treatment, and control of flea and tick infestations. Vet Clin North Am Small Anim Pract.. 2009; 39:(6)1173-1200

Blagburn BL, Young DR, Moran C, Meyer JA, Leigh-Heffron A, Paarlberg T, Zimmermann AG, Mowrey D, Wiseman S, Snyder DE. Effects of orally administered spinosad (Comfortis®) in dogs on adult and immature stages of the cat flea (Ctenocephalides felis). Vet Parasitol.. 2010; 168:(3-4)312-317

Bossard RL, Dryden MW, Broce AB. Insecticide susceptibilities of cat fleas (Siphonaptera: Pulicidae) from several regions of the United States. J Med Entomol.. 2002; 39:(5)742-746

Companion Animal Parasite Council. General Guidelines for Dogs and Cats. 2020. (accessed 20 October 2020)

Cochet P, Birckel P, Bromet-Petit M, Bromet N, Weil A. Skin distribution of fipronil by microautoradiography following topical administration to the beagle dog. Eur J Drug Metab Pharmacokinet.. 1997; 22:(3)211-216

Coles TB, Dryden MW. Insecticide/acaricide resistance in fleas and ticks infesting dogs and cats. Parasit Vectors.. 2014; 7:(1)

Dobler G, Pfeffer M. Fleas as parasites of the family Canidae. Parasit Vectors.. 2011; 4:(1)

Dryden MW, Payne PA, Smith V Evaluation of indoxacarb and fipronil (s)-methoprene topical spot-on formulations to control flea populations in naturally infested dogs and cats in private residences in Tampa FL. USA. Parasit Vectors.. 2013a; 6:(1)

Dryden MW, Ryan WG, Bell M, Rumschlag AJ, Young LM, Snyder DE. Assessment of owner-administered monthly treatments with oral spinosad or topical spot-on fipronil/(S)-methoprene in controlling fleas and associated pruritus in dogs. Vet Parasitol.. 2013b; 191:(3-4)340-346

Fink H, Wennogle S, Davis WL, Von Simson C, Lappin MR. Field comparison of tolerance of a collar containing 10.0% imidacloprid/4.5% flumethrin (Seresto) and a placebo collar placed on cats. J Feline Med Surg.. 2016; 18:(12)1031-1033

Fisara P, Sargent RM, Shipstone M, von Berky A, von Berky J. An open, self-controlled study on the efficacy of topical indoxacarb for eliminating fleas and clinical signs of flea-allergy dermatitis in client-owned dogs in Queensland, Australia. Vet Dermatol.. 2014; 25:(3)195-e49

Halos L, Beugnet F, Cardoso L Flea control failure? Myths and realities. Trends Parasitol.. 2014; 30:(5)228-233

Jacobs DE, Hutchinson MJ, Ryan WG. Control of flea populations in a simulated home environment model using lufenuron, imidacloprid or fipronil. Med Vet Entomol.. 2001; 15:(1)73-77

Lavan RP, Tunceli K, Zhang D, Normile D, Armstrong R. Assessment of dog owner adherence to veterinarians' flea and tick prevention recommendations in the United States using a cross-sectional survey. Parasit Vectors.. 2017; 10:(1)

Linnett P-J. Permethrin toxicosis in cats. Aust Vet J.. 2008; 86:(1-2)32-35

Marchiondo AA, Holdsworth PA, Fourie LJ World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) second edition: guidelines for evaluating the efficacy of parasiticides for the treatment, prevention and control of flea and tick infestations on dogs and cats. Vet Parasitol.. 2013; 194:(1)84-97

McTier TL, Shanks DJ, Jernigan AD Evaluation of the effects of selamectin against adult and immature stages of fleas (Ctenocephalides felis felis) on dogs and cats. Vet Parasitol.. 2000; 91:(3-4)201-212

Mehlhorn H, Mencke N, Hansen O. Effects of imidacloprid on adult and larval stages of the flea Ctenocephalides felis after in vivo and in vitro application: a light- and electron-microscopy study. Parasitol Res.. 1999; 85:(8-9)625-637

Nelson K, Maina AN, Brisco A A 2015 outbreak of flea-borne rick-ettsiosis in San Gabriel Valley, Los Angeles County, California. PLoS Negl Trop Dis.. 2018; 12:(4)

Perrins N, Hendricks A. Recent advances in flea control. In Pract.. 2007; 29:(4)202-207

Ranjan S, Young D, Sun F. A single topical fluralaner application to cats and to dogs controls fleas for 12 weeks in a simulated home environment. Parasit Vectors.. 2018; 11:(1)

Ritzhaupt LK, Rowan TG, Jones RL, Cracknell VC, Murphy MG, Shanks DJ. Evaluation of the comparative efficacy of selamectin against flea (Ctenocephalides felis felis) infestations on dogs and cats in simulated home environments. Vet Parasitol.. 2002; 106:(2)165-175

Rust M. The biology and ecology of cat fleas and advancements in their pest management: a review. Insects.. 2017; 8:(4)

Rust MK, Blagburn BL, Denholm I, Dryden MW, Payne P, Hinkle NC, Kopp S, Williamson M. International program to monitor cat flea populations for susceptibility to imidacloprid. J Med Entomol.. 2018; 55:(5)1245-1253

Sarasola P, Jernigan AD, Walker DK, Castledine J, Smith DG, Rowan TG. Pharmacokinetics of selamectin following intravenous, oral and topical administration in cats and dogs. J Vet Pharmacol Ther.. 2002; 25:(4)265-272

Six RH, Becskei C, Carter L Evaluation of the speed of kill, effects on reproduction, and effectiveness in a simulated infested-home environment of sarolaner (Simparica™) against fleas on dogs. Vet Parasitol.. 2016; 222:23-27

Stanneck D, Kruedewagen EM, Fourie JJ, Horak IG, Davis W, Krieger KJ. Efficacy of an imidacloprid/flumethrin collar against fleas and ticks on cats. Parasit Vectors.. 2012a; 5:(1)

Stanneck D, Ebbinghaus-Kintscher U, Schoenhense E The synergistic action of imidacloprid and flumethrin and their release kinetics from collars applied for ectoparasite control in dogs and cats. Parasit Vectors.. 2012b; 5:(1)

Stanneck D, Rass J, Radeloff I Evaluation of the long-term efficacy and safety of an imidacloprid 10%/flumethrin 4.5% polymer matrix collar (Seresto®) in dogs and cats naturally infested with fleas and/or ticks in multicentre clinical field studies in Europe. Parasit Vectors.. 2012c; 5:(1)

Taenzler J, Wengenmayer C, Williams H Onset of activity of fluralaner (BRAVECTO™) against Ctenocephalides felis on dogs. Parasit Vectors.. 2014; 7:(1)

Taenzler J, Gale B, Zschiesche E, Roepke RKA, Heckeroth AR. The effect of water and shampooing on the efficacy of fluralaner spot-on solution against Ixodes ricinus and Ctenocephalides felis infestations in dogs. Parasit Vectors.. 2016; 9:(1)

Williams H, Young DR, Qureshi T, Zoller H, Heckeroth AR. Fluralaner, a novel isoxazoline, prevents flea (Ctenocephalides felis) reproduction in vitro and in a simulated home environment. Parasit Vectors.. 2014; 7:(1)

Wismer T, Means C. Toxicology of newer insecticides in small animals. Vet Clin North Am Small Anim Pract.. 2018; 48:(6)1013-1026

Wright I. The flea reproductive break point — what it is and how it is pivotal for successful flea control. The Veterinary Nurse.. 2016; 7:(2)84-90

Wright I, Elsheikha H. Flea infestations: epidemiology, treatment and control. The Veterinary Nurse.. 2014; 5:(5)261-269

Flea infestation: a snapshot on the common products and the reasons for treatment failure

02 March 2021
10 mins read
Volume 12 · Issue 2
Figure 1. Adult cat flea.


The reasons why flea infestations remain frequent in companion animals despite the considerable number of anti-flea products is of interest. Successful flea control relies mainly on the use of effective anti-flea products and pet owners adhering to treatment recommendations. When flea infestations continue to persist despite the application of a potent anti-flea product, lack of efficacy may be suspected. In this article, the basics of flea biology and impact of flea infestation on the host are summarised. In addition, the factors that can result in ineffective treatment and control of flea infestation are discussed. Better understanding of the possible reasons can help to inform clinical practice and avoid treatment failures.

With impressive reproductive capabilities, ability to persist in the environment and as pathogenic vectors, fleas are considered to be the most important ectoparasite of dogs and cats (Abdullah et al, 2019). Of the 2500 species worldwide, Ctenocephalides felis (cat flea), Ctenocephalides canis, Pulex simulans and Echidnophaga gallinacea are seen as significant, because of their ability to infest companion animals in large numbers (Blagburn and Dryden, 2009). Among the species mentioned above, the cat flea is the most dominant species affecting cats and dogs. Most investigations that have been carried out focus on this species, therefore the following discussion will be largely limited to the cat flea.

Fleas are laterally flattened, dark brown insects around 2–5 mm in size. Although fleas are wingless (Figure 1), they are highly mobile because of their strong hind legs adapted for jumping (Wright and Elsheikha, 2014). Adult fleas are obligate blood-feeders. Once a host is found, feeding can occur within minutes, subsequently followed by mating. Egg production then begins within 24 to 36 hours of the first blood meal, with up to 50 eggs being laid per egg laying adult female per day. As the eggs are non-adhesive, host movement causes eggs to fall into the environment. Eggs hatch into larvae within 1 to 10 days (Blagburn and Dryden, 2009). Larvae must feed on the blood-rich faeces of adult fleas, known as ‘flea dirt’, in order to successfully undergo two moults and enter the pupal stage (Figure 2). The third stage larvae spin a sticky cocoon covered in environmental debris, in which they moult into flea pupae and mature into adult fleas (Dobler and Pfeffer, 2011). The pre-emerged adults can remain dormant for several months until stimulated by vibrations, carbon dioxide and/or heat. Under most household conditions, the lifecycle is completed within 3 to 8 weeks, but can extend up to 174 days depending on environmental conditions (Blagburn and Dryden, 2009). Colder temperatures in winter can kill off fleas and immature stages residing outdoors. However, fleas inside the home will survive (Beugnet et al, 2004). Fleas are ubiquitous and exposure to flea infestation is hard to avoid. Companion animals that are kept indoors still require treatment as fleas can be brought into the home by other animals or on the owner's clothing. As a result, both the European Scientific Counsel of Companion Animal Parasites (ESCCAP) and the Companion Animal Parasite Council (CAPC, 2020) recommend all year round protection against fleas.

Register now to continue reading

Thank you for visiting The Veterinary Nurse and reading some of our peer-reviewed content for veterinary professionals. To continue reading this article, please register today.