Fleas and Flea Control in Small Mammals

The flea is a small, brown, wingless insect that utilizes specialized mouthparts to pierce the skin and siphon blood. When a flea bites your pet, it injects a small amount of saliva into the skin to prevent blood coagulation. The skin then becomes inflamed, irritated and itchy in reaction to allergens in the saliva.

Though fleas are uncommon in small mammals, they are still a concern, especially if other pets in the household are infested. Small mammals, typically rabbits or ferrets, can become infested with fleas. The flea bites are irritating and quite itchy. The affected animal may scratch and chew madly at himself until the skin is hairless, red raw and weeping serum. A variety of secondary changes may result from self-inflicted trauma, such as scratching, which can lead to widespread hair loss, redness, scaling, bacterial infection, thickening and increased pigmentation of the skin. The distribution often involves the lower back, base of the tail, posterior thighs, ventral abdomen, flanks and neck, but it may become quite generalized in severe cases, leading to total body involvement.

It is important to remember that the flea spends the majority of its life cycle off the host in the environment. For this reason, they may be quite difficult to find on the affected pet. You may find it difficult to understand how such an apparently minimal involvement with fleas can lead to such profound changes. There may not be a single flea to be seen on your pet, but the itch remains and the scratching continues.

Check your pet carefully for fleas or for signs of flea excrement or flea dirt which looks like coarsely ground pepper. When moistened, flea dirt turns a reddish brown because it contains blood. If one pet in the household has fleas, you can assume that all pets in the household have fleas.

The Life Cycle of the Flea

An understanding of the life cycle of the flea is necessary for successful flea control. This cycle has four stages: egg, larva, pupa and adult. The adult flea uses your pet as a place to take its blood meals and breed. Fleas either lay eggs directly on the pet where they may drop off, or they deposit eggs into the immediate surroundings. Because the female may lay several hundred eggs during the course of her life, the number of fleas present intensifies the problem. The eggs hatch into larvae that live in carpeting and cracks and corners of the pet's living quarters. The larvae survive by ingesting dried blood, animal dander and other organic matter. To complete the life cycle, larvae develop into pupa that hatch into adults. The immediate source of adult fleas within the house and outside on lawns is the pupa, not the pet. The adult flea emerges from the pupa, then hops onto the host.

This development occurs most rapidly in a warm, humid environment. The life cycle is variable; pupa can lie dormant for months. However, under temperate conditions, fleas complete their life cycle in about three weeks. It appears that the flea is becoming better adapted to environments that previously failed to support its survival. The inside of your home may provide a warm environment to allow fleas to thrive year round.

Flea Control

There are many products available for treating flea problems in dogs and cats, but many of these products are not safe to use in rabbits or ferrets. Recently, prescription topical flea control products such as Advantage® have been tested in ferrets, and may be safe for use on small mammals. But, before using any of these products, check with your veterinarian.

The safest way to remove fleas from your small mammal is also the most labor intensive. It involves using a flea comb to remove the fleas manually to help reduce the flea load without the worry about chemicals.

The major effort for flea control must be directed at the premises where the eggs, larvae, pupae and adults congregate. It is in the area of control that failure is most likely to occur, so you must be especially diligent here. Because some stages of a flea's life cycle persist for months, chemicals with residual action are needed, and they must be repeated periodically. Sprays applied thoroughly on dog beds, carpets and other infected areas work better than foggers, which spread the insecticide in all directions.

The spray or fogger you choose should contain an adulticide to kill mature fleas, plus methoprene to destroy flea larvae. Use twice in two-week intervals and then every two months during the flea season. Start each year one month before the season begins and then use every two months as before. If your pet lives inside the house, you should spray all rooms used by your pet. Closely follow all directions on the label, being careful of delicate plants, tropical fish and birds, and test every product for possible staining before it is applied.

The vacuum cleaner can be a real aid in removing flea eggs and immature forms. Give special attention to cracks and corners. At the end of vacuuming, either vacuum up some flea powder into your vacuum bag, or throw the bag out; otherwise, the cleaner will only serve as an incubator, releasing more fleas into the environment as they hatch. Hardwood floors should be mopped with an insecticide sprayed lightly over the mop head.

Because fleas spend most of their life cycle off the animal and the life cycle varies in duration, complete flea control can be extremely difficult. The major problem is continued environmental exposure. It is probably true to say that for every flea on the animal, there are 100 in the environment. Simultaneous treatment of all animals and their living quarters is crucial. Treatments should be thorough and repeated as necessary. Failure to do so may allow some fleas to survive and reinfect the animal, thus wasting time, energy and money spent on flea control. Six to eight weeks of conscientious effort may be needed to eliminate fleas completely.

In some cases, it is wise to obtain the services of a licensed pest control company. These professionals have access to a variety of insecticides and they know what combinations work best in your area.