External parasites are generally found on or in the skin and are nuisance pests because they bite or annoy both humans and their pets.
Fleas, mange mites, and ticks are the most frequently encountered and most troublesome pests that attack humans and their pets.
Fleas are small (1/16"), dark, reddish-brown, wingless, blood-sucking insects. Their bodies are laterally compressed, (i.e., flattened side to side) permitting easy movement through the hairs on the host's body. Their legs are long and well adapted for jumping. The flea body is hard, polished, and covered with many hairs and short spines directed backward. The mouthparts of an adult flea are adapted for sucking blood from a host.
Several species of fleas may be pests in Florida, and five kinds have been found on a single animal. The cat flea is the most frequently found flea, although the dog, human, and sticktight fleas are also found in Florida. Fleas may attack a wide variety of warm-blooded animals including dogs, humans, chickens, rabbits, squirrels, rats and mice.
The female flea lays her tiny, white eggs loosely on the hairs, in the feathers, or in the habitat of the host. The eggs readily fall off the host onto the ground, floors, bedding, or furniture. Some fleas can lay 500 eggs over a period of several months by laying batches of three to eighteen eggs at a time. The tiny eggs hatch in one to twelve days after being deposited.
The white, worm-like larva avoids light and feeds on particles of dead animal or vegetable matter generally present in cracks and crevices. Within 7 to 14 days, unless food has been scarce, the third larval stage is completed, and the larva spins a tiny cocoon and pupates. Usually after a week the adult flea emerges and begins its search for blood.
Several species of ticks attack dogs, but cats are rarely infested. Many of the dog ticks are known as wood ticks and infest dogs when they run through the woods or fields. Ticks can also annoy people but humans are not the preferred host.
Ticks are not insects, and are closely related to the spider. Adult ticks have eight legs. All ticks are parasitic, feeding on the blood of animals.
Of the ticks found in Florida, the brown dog tick, and the American dog tick, are the most troublesome. The brown dog tick rarely bites humans, but infestations are frequently found on dogs and in the home. The American dog tick attacks a wide variety of hosts, including humans, but rarely will infest homes. Ticks should be removed from pets and humans as soon as they are noticed. Ticks should be removed carefully and slowly. If the attached tick is broken, the mouthparts left in the skin may transmit disease or cause secondary infection. Ticks should be grasped with tweezers at the point where their mouthparts enter the skin and pulled straight out with firm pressure. A small amount of flesh should be seen attached to the mouthparts after the tick is removed.
People entering tick infested areas should keep clothing buttoned, shirts inside trousers, and trousers inside boots. Do not sit on the ground or on logs in bushy areas. Keep brush cleared or burned along frequently traveled areas. Repellents will protect exposed skin or clothing. However, ticks will sometimes crawl over treated skin to untreated parts of the body.
Pesticidal control of ticks may require both pet treatment and treatment of the infested area. If a heavy tick infestation occurs it is necessary to treat pets, home, and yard at the same time. Heavy infestations of ticks on the animal should be controlled by spraying or dipping. See your veterinarian for products and recommendations for direct pet treatment.