The Flea Life Cycle in dogs

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. Fleas are also an intermediate host for tapeworms.

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.

The Flea Life Cycle:

An effective flea-control strategy requires an understanding of the flea life cycle. Fleas need a warm, humid environment to flourish and reproduce. The higher the temperature and humidity, the more efficient their reproduction. The adult flea can live up to 115 days on a dog, but only one or two days off her.

After taking a blood meal, fleas mate on the skin of the dog. The female lays eggs within 24 to 48 hours, and may produce up to 2,000 eggs in a four- month life span. The eggs fall off and incubate in your home beneath furniture and in carpets, cracks, and bedding. Deep pile and shag carpets make an ideal environment for egg development.

In 10 days the eggs hatch into larvae that feed on local debris. Larvae spin a cocoon and go into a pupal stage that lasts for days or months. Under ideal temperature and humidity conditions, fleas can emerge rapidly. After hatching, immature adult fleas have two weeks to find a host.

At any given time, about 1 percent of the flea population is composed of adult fleas, while 99 percent remain in the invisible egg, larval, and pupal stages. An effective flea-control program must eliminate this large reservoir.