Of the 850 species of ticks worldwide, the one posing the biggest threat to our dogs and us is the deer or black-legged tick. It carries Lyme disease as well as ehrlichiosis and babesiosis and is suspected of transmitting the virus that causes encephalitis in dogs.

Unlike fleas, ticks are not insects. They are members of the arachnid family. Like fleas, however, they are parasites that need blood meals from their host to survive. The female tick lays her eggs on the ground in the early spring. By late spring, they hatch and larvae emerge. These attach to small animals like mice for a blood meal.

Once the larvae have eaten their fill, they drop off and molt, shedding their hard exoskeletons and morphing into their nymph phase. The nymph is dormant over the winter but it wakes up hungry in the spring. The nymph's most common host is the white-tailed deer, but if it gets the chance, it will attach itself to humans and pets as well.

Ticks do not jump like fleas. They crawl onto their host, usually from a hiding place in tall grass. They respond to body heat, carbon dioxide, and the vibrations created by footsteps and they like warm hairy places. To transmit a disease, they have to be dug into their host for twenty-four hours.

On unvaccinated dogs, Lyme disease shows up about four weeks after the tick has bitten them. The symptoms are lameness, fever, lethargy, swollen joints, depression, and loss of appetite. If not treated immediately with a regimen of antibiotics, joint damage will progress and lesions will form on the kidneys, possibly leading to kidney failure. Other devastating effects are neurological and heart problems. Lyme disease is often hard to diagnose, so if you live in an area where ticks are prevalent and your dog spends a lot of time out-of-doors, it should receive the Lyme vaccination.

Ticks thrive in wooded areas, so cut back brushy areas on your property, get rid of wood and rock piles, and keep the lawn mowed. If you and your dog go walking in the woods, spray your dog with Permethrin or have it wear a tick collar containing Amitraz. Preventic and Tick Arrest are two such collars. They offer protection against ticks only, not fleas. Topical products such as Frontline, Advantage, Revolution, K9 Advantix, and Biospot will also kill ticks. However, on all such products, it is vitally important that you buy only the formulas labeled for use on small dogs.

If you find a tick on your dog, don't pull it off with your bare hands. Use a tissue, latex gloves, tweezers, or a tick remover (available at pet supply stores) to pull it off, making sure to remove its mouthparts in the process. Don't squish it or flush it down the toilet. Instead, drop it into a container of alcohol or flea and tick spray to kill it. If the resulting bite on your dog looks red and swollen, wash with hydrogen peroxide and apply an antibacterial ointment.

Observe your dog closely after applying any flea and tick products. If you suspect an adverse reaction, bathe immediately with a mild dog shampoo and rinse thoroughly. If the dog appears lethargic, is losing its balance, or shows signs of seizure or vomiting, take it to your vet right away. You should also report the incident to the product manufacturer and to the U.S. Environmental Protection Agency (EPA).

Today, we are fortunate to have such an arsenal of products to protect our dogs from fleas and ticks, but they must be used wisely. Combining such products willy-nilly without reading labels could cause more problems than the pests you are trying to prevent.