The ordinary cat flea (Ctenocephalides felis)is the leading cause of itching and scratching in dogs and cats. Fleas
survive by jumping onto a host animal, cutting open their skin, and feeding
on the blood. In many dogs, the bites cause only a mild itch, but a heavy
infestation in a puppy or small dog can cause severe anemia
and even death.
Some dogs develop a marked hypersensitivity to the saliva of fleas and
experience intense itching which results in skin abrasions, hair
loss, and secondary pyoderma (see Flea Allergy
Dermatitis). Fleas are also an intermediate host for tapeworms.
Heartworm disease, so named
because the adult worms live in the right side of
the heart, continues to be a major problem for many species of animals.
Heartworms are spread by mosquitoes, and thus are found throughout the world.
In the United States the prevalence is highest along the southeastern Atlantic
and Gulf Coasts, but heartworm has been found in all 50 states. The disease is
less prevalent at higher elevations.
The highest infection rates (up to 45 percent) in dogs
Flea infestation can be diagnosed by finding fleas on the dog or by seeing
black-and-white, salt-and-pepper-like grains in the coat. These particles are
flea feces (the “pepper”) and flea eggs (the “salt”). Fecal material is made up
of digested blood. When brushed onto a wet paper, it turns a reddish brown.
The adult flea is a small dark brown insect about 2.5 millimeters in size
and can be seen with the naked eye. Although fleas have no wings and cannot
fly, they do have powerful back legs and can jump great distances. Fleas move
through the hair rapidly and are difficult to catch. Run a fine-tooth flea comb
through the hair to look for fleas on your dog’s back, in the groin, and around
the tail and hindquarters. Itching is most pronounced in these areas.
New Methods of Flea Control
Program (the brand name for lufenuron)works by inhibiting flea eggs from
growing and hatching. This leads to a steady drop in the number of new fleas in
the environment. Its affect is limited to the hard outer shell of the flea,
making it completely harmless to mammals. However, because mature fleas are not
affected, it can take 30 to 60 days or longer for the adult fleas on the dog to
die of old age before you notice a reduction in itching and scratching.
For more immediate results, and especially if the dog is suffering from flea
allergy dermatitis, Program should be combined with a flea shampoo or some
other topical insecticide treatment. Advantage or Frontline can be added to
Program to kill adult fleas within one to two days. It may be necessary to
eliminate fleas on the premises using insecticides.
Sentinel combines Program with the heartworm preventive Interceptor. This broad-spectrum
preventive not only controls fleas, but also protects against heartworms, ascarids, hookworms, and whipworms.
Advantage (imidacloprid) isa once-a-month liquid preparation that kills
fleas by direct contact. Fleas don’t have to bite the dog for the preparation
to work. Advantage comes in a tube and is applied to the dog’s skin between the
shoulder blades (you must carefully part the hair to make sure you get the
liquid on the skin) and to three or four additional sites along the dog’s back
for larger dogs. The amount to apply depends on the size of the dog, and will
be prescribed by your veterinarian. One application protects a dog for up to 30