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LYME
DISEASE What
is Lyme Disease? Common
in North America, the disease is now being recognised more frequently in
Britain. Lyme Disease (not Lyme's Disease) is caused by a spirochete called
Borrelia. A spirochete is a type of
bacterium. It is transmitted
to dogs through the bite of a tick. Once
in the blood stream, it is carried to many parts of the body.
It is especially likely to localise in joints. It
was first thought that only a few types of ticks could transmit this disease,
but now it appears that several common species may be involved. Can
this disease also affect people? Yes,
but people do not get it directly from dogs.
They get it from being bitten by the same ticks that transmit it to dogs.
Therefore, preventing exposure to ticks is important for you and your
dog. How
is a dog affected? Many
people having the disease develop a characteristic rash at the site of the bite
within 3 to 30 days. For these
people, the disease can be easily diagnosed at an early stage.
However, symptoms of Lyme Disease are more difficult to detect in animals
than in people.
This
characteristic rash does not develop in dogs or cats.
Because the other symptoms of the disease may be delayed or not
recognised, and because the symptoms are similar to those of many other
diseases, Lyme Disease in animals is often not con_sided until other diseases
have been eliminated.
Many
dogs affected with Lyme Disease are taken to a veterinary surgeon because they
seem to be experiencing generalised pain and have stopped eating.
Affected dogs have been described as if they were "walking on
eggshells" Often these animals
have high fevers. Dogs
may also become lame because of the disease.
This painful lameness often appears suddenly and may shift from one leg
to another. If untreated, it may
eventually disappear, only to recur weeks or months later. Some
pets are affected with the Lyme Disease organism for over a year before they
finally show symptoms. By this
time, the disease may be quite widespread in the body.
How
is Lyme Disease diagnosed? Dogs
with lameness, swollen joints, and fever may be
suspected of having Lyme Disease. However,
other diseases may also cause these symptoms.
There are two blood tests that may be used for confirmation. The first is an antibody test.
This test does not detect the actual spirochete in the blood but does
detect the presence of antibodies created by exposure to the organism.
A test can be falsely negative if the dog is infected but has not yet
formed antibodies, or if it never forms enough antibodies to cause a positive
reaction. This may occur in animals
with suppressed immune systems. Some
dogs that have been infected for long periods of time may no longer have enough
antibodies present to be detected by the test.
Therefore, a positive test is meaningful, but a negative is not. The
second test is the polymerase chain reaction (PCR) test. This
is also known as DNA testing. It is
very specific and sensitive. However,
not all dogs have the spirochete in their blood cells.
If a blood sample is tested, a false negative may occur. The best sample for testing is the fluid from an affected
joint. How
is Lyme Disease treated? Because
the Lyme spirochete is a bacterium, it can be controlled by antibiotics.
However, a lengthy course of treatment is necessary to completely
eradicate the organism. The initial
antibiotic selected to treat an infected pet may not be effective against the
disease, especially if the infection is long-standing.
In this situation, a switch to another antibiotic is often effective.
Occasionally, the initial infection will recur, or the pet will become
reinfected after being bitten by another infected tick. How
can I prevent my dog from getting Lyme Disease? The
key to prevention is keeping your dog from being exposed to ticks.
Ticks are found in grassy, wooded, and sandy areas.
They find their way onto an animal by climbing to the top of a leaf,
blade of grass, or small tree.
Here they wait until their sensors detect a close-by animal on which to
crawl or drop. Keeping
animals from thick underbrush reduces their exposure to ticks.
Dogs should be kept on paths when
walked in woods or tall grass areas. How
do I remove a tick from my dog? Check
your pet immediately after it has been in a tick-infected area.
If you find a tick moving on your pet, the tick has not fed.
Remove the tick promptly and place it in rubbing alcohol or crush it
between two solid surfaces. If you
find a tick attached to your pet, grasp the tick with fine tweezers or your
finger nails near the dog's skin and firmly pull it straight out.
You may need another person to help restrain your dog.
Removing the tick quickly is important since the disease is not
transmitted until the tick has fed for approximately 12 hours.
If you crush the tick, do not get the tick's contents, including blood,
on your skin. The spirochete that
causes Lyme Disease can pass through a wound or cut in your skin. Is
there a vaccine that will protect my dog from Lyme Disease? A
vaccine is now available in North America to protect against Lyme Disease.
This vaccine is initially given twice, at two week intervals.
An annual booster is necessary.
The vaccine has been shown to be safe and very effective. |