By Dr. Paul Magrath,DVM
Fleas are a relatively common ectoparasite seen in companion animals. Although there are over 2,000 species of fleas, the majority of flea infestations on pet dogs and cats are caused by Ctenocephalides felis felis. However, it is important to note that C. felis is not limited to companion animals and can be found on a variety of wildlife such as rodents, coyotes, foxes and raccoons that act as reservoirs for infestations of pets. Fleas are also very prolific breeders. Female adult fleas tend to start feeding within minutes of attaching to a dog or cat and can mate and produce eggs within 24 hours. A female can lay 40-50 eggs per day and approximately 50% of these eggs will be female The eggs then fall off the host with the biggest concentration being in areas where the pets spend their most time (i.e. pet bedding, rugs, etc). Flea eggs tend to hatch within 2-10 days and the larva then burrow deep into carpet and debris because of their sensitivity to heat and desiccation. The larva will then pupate within 1-2 weeks. Immature adults emerge from the pupa within 7 days in most ideal circumstances or the pupa may survive for over 6 months. Vibration, heat and CO2 tend to stimulate emergence. Ambient temperature and humidity are critical for flea development. For larvae, the best conditions are 65-80OF (18-27OC) and high humidity. It is for these reasons that flea control is recommended year-round. A sudden spike in temperature/humidity can cause dormant pupae to hatch and flea re-infestations can occur.
Flea control is important because flea infestations can lead to a variety of conditions. Because fleas feast on the host’s blood, heavy flea infestations can lead to flea bite anemia. Fleas can also irritate the skin and cause flea-bite dermatitis. Some companion animals are allergic to flea bites and can develop flea allergy dermatitis. Fleas can also transmit a variety of disease including Rickettsia typhis, R. felis, Bartonella henselae and Yersinia pestis (bubonic plaque). Fleas can also act as intermediate hosts for tapeworms.
Treatment of fleas is not just as simple as treatment with a good high quality flea control. Because only about 5% of the flea population is adult fleas, it is just as critical to treat the other 95% of the flea population living in the environment or re-infestations can easily occur. Treatment of the indoor environment using a flea spray designed to quickly kill fleas and stop their reproduction. It is also importance to wash all bedding and vacuum all carpets and upholstery and discard the vacuum bag to prevent the flea eggs from hatching in vacuum bags and spreading through the home. In cases of heavy flea infestation, sometimes a pet’s outdoor environment will also need to be treated for fleas. Equally important to treatment of the environment, is the treatment of all pets in the household for fleas because typically when one pet has fleas, the rest in the household do as well due to close proximity.
Picking a good flea control can seem like a daunting task. There are hundreds of different flea controls currently on the market with new options popping up yearly. My best advice to follow recommendations set forth by your local veterinarian. Veterinarians deal with flea infestation problems on their patients on a weekly basis and have expert knowledge on which products work and which ones do not. The general rule of thumb is that most generic, off-brand flea controls do not work well. Prescription based products such as Trifexis, Revolution, Advantage Multi and Comfortis tend to work really well if they are given based on labeled instructions. Some of these products have added benefits for heartworm prevention, deworming and treatment/prevention of ear mites. These products meet all requirements of the FDA and EPA to be safe and effective. Flea controls meant for dogs should NEVER be used on cats especially if they contain permethrin as this can cause extreme toxicity in cats. All natural products such as diatomaceous earth and garlic sound like good alternatives to flea control but in reality they do not work as effectively and can be potentially toxic to animals.
In summary, fleas are common parasites seen on domestic animals that can cause a variety of diseases. Successful flea control relies on treatment of all animals in the household with a good, high quality, flea control year-round. The appropriate flea control will vary from pet to pet and is based on your pet’s life style and risk factors. It is best to consult with your veterinarian during your pet’s annual preventative health care exam to determine which product is most appropriate.