A tick has a one-piece body. The harpoon-like barbs of its mouth attach to a host for feeding. Crab-like legs and a sticky secretion help hold the tick to the host. When attempting to remove a tick, to prevent the mouth part from coming off and remaining embedded in the skin, grasp the mouth close to the skin with tweezers and pull gently.

Ticks are not insects like fleas, but arachnids like mites, spiders and scorpions. They have a four-stage life cycle, illustrated in a PDF file, eggs, larvae, nymphs, and adults. Adult females of some species lay about 100 eggs at a time. Others lay 3,000 to 6,000 eggs per batch. Six-legged larvae hatch from the eggs. After at least one blood meal, the larvae molt into eight-legged nymphs--in some species, more than once. Final nymphs molt into adult males or females, also with eight legs. Depending on its species, a tick may take less than a year or up to several years to go through its four-stage life cycle. While ticks need a blood meal at each stage after hatching, some species can survive years without feeding.

The United States has about 200 tick species. Habitats include woods, beach grass, lawns, forests, and even urban areas.

Ticks may carry various infectious organisms that can transmit diseases to cats and dogs, including the following (listed with possible symptoms):
  • babesiosis--lethargy, appetite loss, weakness, pale gums
  • ehrlichiosis--high fever, muscle aches
  • Lyme disease--lameness, swollen joints, fever, poor appetite, fatigue, and vomiting (some infected animals show no symptoms)
  • tick paralysis in dogs--gradual paralysis, seen first as an unsteady gait from uncoordinated back legs (some infected dogs don't develop