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Don't Be Ticked Off by Lyme Disease

Pet Column for the week of May 17, 1999

Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Sarah Probst
Information Specialist

Enjoy outdoor fun with your pet, but be sure to use protection against tick-borne diseases,
such as Lyme disease. Ticks carrying Lyme disease were first identified in Illinois in 1987.
Since then the problem has been found in over 26 Illinois counties.

Dr. Carl Jones, professor of parasitology at the University of Illinois College of Veterinary
Medicine in Urbana, does research on Lyme disease. "Lyme disease is preventable, even if
you have ticks in the area. but it is important to know when and where Lyme disease is
likely to occur," says Dr. Jones.

Lyme disease is caused by a spirochete called Borrelia burgdorferi, which is found in
certain species of ticks in the northeast, mid-Atlantic, upper Midwest, and far western
regions of the United States. "The habitats associated with Lyme disease are wooded sites,
especially hardwoods, and places with diverse wildlife, especially the white-tailed deer and
the white-footed mouse," says Dr. Jones.

The tick life cycle determines when the disease is transmitted. "Tick eggs are laid in the
spring and the larvae emerge one month later. The larvae feed once in the summer, usually
on small mammals such as rodents, and then overwinter. That next spring the larvae molt
into nymphs, which feed on dogs, deer, or human beings during late spring and early
summer," explains Dr. Jones. The nymphs are very small, the size of a small mole, and very
difficult to see in your pet's fur.

"In fall the nymphs molt into adults and feed on larger mammals, such as white-tailed deer.
They mate, lay their eggs, and die. Nymphs are the most likely source of infection because
you don't see them well enough to pull them off, but adults have the highest rate of infectivity
because of their longevity and greater chance for exposure," says Dr. Jones. Ticks must be
attached for 24 hours before the spirochete is transmitted through the saliva to the bite

"It is unlikely that you will be infected through your pet unless you are careless about tick
handling when you remove ticks for your pet. Remove the ticks by grasping the mouth parts
with tweezers and pulling the tick straight away from the body. Be sure to check yourself
for ticks if you have been in the same habitat as your pet."

If infection occurs in your pet, the spirochetes migrate, invade and penetrate into connective
tissues, skin, joints, and the nervous system. Clinical signs result from the host's
inflammatory response to the organism. Your pet may show signs of fever, arthritis, shifting
leg lameness, articular swelling, large lymph nodes, anorexia, and general malaise between 2
and 5 months after exposure to the tick, but the signs are not as obvious as in human Lyme
disease. Your pet may need treatment for 30 days or more and may experience a relapse.

Appropriate prevention depends on exposure to probable Lyme disease habitats. There are
vaccines for both dogs and humans, but their protection is not absolute. Consider a
vaccination for your pet if you and your pet do a lot of hunting, camping, or other activities
in wooded areas where Lyme disease is known to exist.

Another preventive mechanism is keeping ticks from infecting your pet in the first place.
Consult with your veterinarian before using over-the-counter tick prevention products. One
of the most effective aids to prevention is a once-a-month veterinary-recommended topical
application to rid your pet of ticks and fleas.

For more information on Lyme disease and its prevention, contact the state department of
health or your physician (for you), or your local veterinarian (for your pet).