Types of Fleas that Bother Dogs: Cat Flea & Sticktight Flea

Fleas

Cat Flea

The cat flea is the most common ectoparasite of both dogs and cats in the United States and has been found on over a dozen other animals. While it does serve as the intermediate host of some tapeworms, its main effect is the itching and irritation produced by its bite (along with flea allergy dermatitis in susceptible animals).

Appearance of Cat Flea

Cat fleas are laterally-flattened, wingless insects approximately one-eighth inch long when engorged (double their unfed size). Under magnification they can be seen to have both genal and pronotal combs (ctenidia), differentiating them from most other fleas of domestic animals.

Biology And Behavior of Cat Flea

Cat fleas have four stages in their development -- egg (Figure 1), larva (Figure 2), pupa and adult (Figure 3). The eggs, which are smaller than the period at the end of this sentence, are laid as the female feeds on the host and sift through the animal's coat to collect in the environment. The legless larvae which hatch from the eggs feed on excrement produced by the adult fleas and reach a length of about one-eighth inch. Outdoors these larvae develop in shaded soil and indoors they develop best in carpet. While under good conditions the larval stage takes only about a week, cool temperatures and low humidities can extend larval development for several weeks. The larvae spin cocoons of silk in which they incorporate debris from their environment (soil outdoors, soil and carpet fibers indoors) for pupation. The pupa develops and metamorphoses into an adult flea within this cocoon. This stage is the most variable in length as the pharate (pre-emerged) adult remains within the cocoon, sometimes for months, until signaled to emerge by such stimuli as pressure or carbon dioxide.

Cat flea eggs

CREDITS: N. Hinkle, University of Florida
Figure 1. Cat flea eggs.

CREDITS: J. F. Butler, University of Florida
Figure 2. Cat flea larva.

Cat flea adult

CREDITS: N. Hinkle, University of Florida
Figure 3. Cat flea adult.

Footnotes

  1. This document is ENY-263, one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: March 1994. Revised: April 2003. Please visit the EDIS Website at http://edis.ifas.ufl.edu.
  2. N. C. Hinkle, Department of Entomology, University of Georgia, Athens, GA (formerly University of Florida student), P. G. Koehler, professor/extension entomologist, and F. M. Oi, assistant extension entomologist, Entomology and Nematology Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.

Sticktight Flea

The sticktight flea is an occasional pest of dogs and cats, as well as of chickens and other birds. Poultry sometimes have clusters of these fleas around the eyes, comb, wattles, and other bare spots. These dark-brown fleas have their heads embedded in the host's flesh and cannot be brushed off. Sticktight fleas are commonly a problem on dogs which have contact with barnyard fowl. Typically, on dogs and cats, the sticktight fleas will be found around the margin of the outer ear or occasionally between the toe pads. They have also been reported from horses and humans.

Health Effects of Sticktight Flea

While sticktight fleas are not known to transmit any diseases, their attachment can lead to secondary infection. Irritation produced by feeding, along with infection and the sheer numbers which may be present, can cause the eyes to swell shut and the host can starve to death. Young animals succumb to anemia produced by the fleas' feeding.

Biology and Behavior of Sticktight Flea

Before mating, both sexes hop around freely. However, upon fertilization the female attaches (by her mouthparts) to the host and spends the rest of her life in that position. Eggs are laid and fall to the ground where the developing larvae feed on organic debris including the adult flea feces. After several weeks the larva spins a silken cocoon covered with dust and dirt in which it pupates. The adult may emerge within days or, under adverse environmental conditions, may remain quiescent within the cocoon for several weeks or months. The newly-emerged adult flea seeks a host, mates, and the females attach to the host to begin a new generation.

Appearance of Sticktight Flea

Under magnification it is apparent that the sticktight flea lacks both the genal and pronotal combs (ctenidia) possessed by the cat flea. The sticktight flea is one of the smallest fleas found on domestic animals, usually measuring less than half the size of the cat flea.

Control of Sticktight Flea

Sticktight fleas can be removed with tweezers by grasping and pulling firmly. An antibiotic ointment should be applied to the area to prevent infection. If fleas are too numerous to remove individually, a flea product registered for on-animal use should be applied according to label instructions. Care should be taken not to get any product into the animal's eyes. To avoid reinfestation, treat the premises to eliminate flea larval development. There are several insecticides registered for treatment of outdoor areas for fleas. Burning of infested organic material, such as animal bedding and poultry litter, has been recommended.

Footnotes

1. This document is Fact Sheet ENY-244, a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: October 1991. Revised: August 2001.

2. P. G. Koehler, professor, Entomology and Nematology Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611.

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