In the spring and summer the fleas will be out in force again. These pesky little parasites afflict many of our pets, including ferrets.  In some areas of the country, fleas are a year-round problem.  Let’s take a look at how fleas can be safely controlled in ferrets using the products available on the market.  Remember to always check with your veterinarian first before using any new product on your pet to ensure its safe use.

The Ctenocephalides flea species (C. felis and C. canis) is usually the one affecting dogs, cats, ferrets, rodents, rabbits, and many other animals , but other species such as Pulex irritans (the human flea) Parascaris meli (the badger flea), Ceratophyllus sciurorum (the squirrel flea) and Ceratophyllus visin (the mink flea) have also been reported, depending on the environment. 

The adult flea only lives on the host animal long enough to acquire its blood meal and lay its eggs.  The flea spends part of its time in the surrounding environment laying more eggs and waiting for its next victim.  Fleas are transmitted either by direct contact with another infested animal or by contact with a flea-infested environment.  Adult fleas live about 3 to 4 months and the entire life cycle from egg to adult can take as little as two weeks!  These fleas can also feed on humans, although we are not their preferred host. 

Some pets (as well as some humans) develop an allergic skin reaction to flea saliva resulting in scabs, sores, intense itching and hair loss.  Identifying fleas or flea excrement (“poop”) on the animal will confirm the diagnosis.   It is important that flea control be aimed at removing the fleas from all the animals in the household as well as from the environment or the fleas will not be eliminated!

Although there are a number of flea control products on the market today, none of the treatments discussed below have been approved by the U.S. Department of Agriculture (USDA) for use in ferrets.  Therefore, if you use any of these products, it will be at your own risk.  Some veterinarians require your signature on a release form before using a non-USDA approved product so that there is a clear understanding of your responsibility in case of an adverse reaction.  In addition, the drug companies that produce these flea control drugs are not liable for the product’s use outside of the recommended species and should not be held responsible if a problem occurs.   Because the process is extremely time consuming and expensive, it is unlikely that these products will acquire official USDA approval for use in ferrets.

Long standing, traditional treatments for fleas include flea shampoos, dips, sprays, spot-on treatment or powders that contain  pyrethrins, organophosphates (tetrachlorvinphos), or carbamates (carbaryl or propoxur) which are all strong insecticides.   Serious and sometimes fatal reactions have occurred in cats, dogs and ferrets exposed to these products.

Flea Control Products

In the last several years there have been a number of new products on the flea control market for dogs and cats. These include Advantage (now Advantage II), Revolution, Frontline, and Program. They have a different approach to flea control that is less toxic to both the pets and their human companions. However, remember that none of these products have been officially approved for use in ferrets. However all of them have been used by ferret owners on their pets in various parts of the country and the world and so far the reports of toxicity are uncommon.  These products currently appear to be the safest and most effective to use in most pets.

It is strongly suggested that if you have a serious flea problem that you discuss the use of one of these products with your veterinarian. Please note that some of these products also kill ear mites, ticks or prevent heartworm disease, all of which can affect ferrets.  Therefore with your veterinarian’s help, you can select the product the fits your ferret’s situation best.

Please consult with your veterinarian for the appropriate dose of any medication.  Knowing the weight of your animal will be important to giving the proper dose.

*NOTE:  All of the medications listed below are designed to be applied or given once a month during the flea season (which is all year round in some parts of the country).  For medications that are applied to the skin, please put it between the shoulder blades where it is difficult for your pet to lick and watch your pet carefully for the first hour after application to make sure there are no adverse reactions and check your ferret frequently for the first 24 hours the first time you use a product.

Advantage II (produced by Bayer) (Adulticide) This is a topical medication where the active ingredients are imidacloprid, which acts on the nervous system of the flea to cause paralysis and subsequent death, and pyriproxyfen, an insect growth regulator which prevents immature fleas from reaching maturity.  In combination these two ingredients kill all flea life stages on the treated ferrets and its surroundings and helps prevent fleas from infesting your home.  This product kills 98-100% of the adult fleas within 24 hours of application and thus kills female fleas before they have a chance to lay eggs.  Advantage is not absorbed into the blood stream or internal organs.  It is applied topically and spreads through skin oils into the hair follicles.  Although many veterinarians use this product on ferrets, rabbits, chinchillas, and guinea pigs, it has not been officially tested or approved for use in these species.  It is important to prevent the pet or its cagemates from licking the material while it is wet.  It is water soluble so bathing or excessive exposure to water can reduce the effectiveness of the product and it may have to be reapplied more frequently in these cases.  This product can stain furniture and remove the finish from some materials if there is contact with the wet product.  Advantage does not kill fleas, ear mites or prevent heartworm.

Advantage Multi for Cats (produced by Bayer)  (Adulticide) The active ingredients are imidacloprid 10% and moxidectin 1% topical application.  Ferrets with established flea infestations given this product have 100% of the fleas killed on day 1 after treatment and over 90% prevention of further infestation for up to 30 days after treatment.  Advantage Multi for Cats does not kill ticks but will control ear mites and will prevent heartworm.

Program (produced by CIBA Animal Health) and Sentinel (Novartis Animal Health) (Insect Growth Regulator)  This product is a pill where the active ingredient lufenuron is an insect growth regular.  It interferes with the development of normal chitin which is the hard outer shell of the flea, and thus results in the death of the immature flea.  It is not an insecticide and does not kill the adult flea, but rather prevents the immature fleas from reaching maturity so that over time the fleas in the household die out. The product is given orally once a month. It appears to be a very safe drug in all animals in which it has been used.  Rare side effects might include vomiting, lethargy, diarrhea, itchy skin or loss of appetite.  It may be necessary to use it initially with an adulticide product until the flea population in the household is under control.  There is about a 6 to 8 week lag period between starting with Program and the reduction of adult fleas on the pets. Program does not prevent heartworm or kill ticks or ear mites.

Frontline (produced by Merial) (Adulticide)  The active ingredient fipronil (9.7% solution) is an insecticide from a family of drugs called phenylpyrazoles. It kills 96% of adult fleas in 2 hours on contact and 100% of adult fleas in 24 hours.  In addition, it kills 100% of ticks within 48 hours, and most die before they can attach.  Frontline is not water soluble so sunlight, bathing and water do not change the effectiveness of this product.  The toxic action of fipronil is very specific to invertebrates such as insects and arthropods, and apparently does not affect mammals.  It is applied directly to the skin with a spray or as a spot type application and is reapplied monthly. It is not absorbed into the bloodstream. This product can be used in conjunction with Program. Frontline does not prevent heartworm or kill ear mites but  it will kill all four major tick species.

Revolution (produced by Pfizer) (Adulticide)The active ingredient in this product is selamectin.  Selamectin is a semisynthetic avermectin.  After Revolution is applied to the skin it is absorbed into the bloodstream and eventually distributed back into the skin where it kills the flea when it is feeding  Revolution acts both internally and externally. Bathing does not change the effectiveness of Revolution once it dries. Revolution controls fleas, heartworms, ear mites, one species of tick (Dermacentor variabilis – American dog tick) and sarcoptic mange mites.

“Natural” flea control products - None of these products will effectively kill fleas, but may act as repellents to keep the fleas away from the pet. Some products are added to the pet's food such as garlic, Brewers yeast and sulfur which are absorbed by the body and may alter the “taste” or smell of the pet's skin acting to repel the fleas. Products used only topically include pennyroyal oil, melaleuca oil, lavender oil, citronella oil and lemon oil. Adverse reactions to these products can occur due to a local allergic reaction, applying too much or if the ferret licks and swallows the product causing a toxic reaction. I don't generally recommend using any of these products as an effective means of total flea control in the ferret. If you do choose to use them, please observe for any toxic reactions and use environmental flea control to further reduce the flea population.

Environmental Flea Control

The best environmental control is a clean environment. Vacuum frequently and either throw out the bag or clean the canister each time or use a boric acid salt product in the bag to dry out and kills the fleas and eggs you collect. In addition wash the pet's bedding at least once a week in hot soapy water. Steam clean the carpeting a few times a year to kill parasites of all types. Boric acid salt coats the fleas and their larva and removes the moisture from their bodies and thus kills them. You can use boric acid salt products on the floors and carpets once or twice a year to kill fleas. There are pest control companies that can apply this product for you. Boric acid salt products should never be used directly on the pet and pets as well as humans should be protected from the dust during application in the environment.

For flea control in the yard you can purchase nematodes, which are microscopic worms found in some gardening catalogs, which eat immature fleas and eggs. These nematodes have to be maintained in a moist area. In addition, ants love to eat fleas and their families and you might want to think twice before destroying all the ant nests in your yard. For very serious infestations, either inside or out, it may be necessary to use insecticide foggers or environmental sprays which contain a variety of ingredients including growth-inhibiting hormones. If the infestation is difficult for you to control I recommend consulting a pest control specialist for safe effective solutions.

In conclusion, remember that you must control the fleas on all the mammal pets in the household and in the environment as well. With several options available you should be able to be flea-free this year!