The State of Lyme Disease

Excerpted from  ( Posted: 10/04/2011)

Lyme disease (known as equine borreliosis in horses) is the most common human
disease transmitted by arthropods in North America. Ixodes sp. ticks, the vector of Lyme disease, are being described in areas where they have not been reported before. States in the Northeast, mid-Atlantic, and the Great Lakes region have the highest number of reported human Lyme disease cases in humans,
and horses in these areas are at high risk of exposure to the Lyme organism,  Borrelia burgdorferi.

Any horses housed outdoors are at risk due to increased exposure to ticks and the aggressive feeding of the Ixodes ticks. The small ticks are difficult to see in the hair coat. It is thought that ticks must be attached 12 to 24 hours before humans are infected, as is likely to be the case in horses.

Clinical signs associated with equine borreliosis are variable and include shifting leg lameness, myalgia (muscle pain), dermal hypersensitivity, behavior changes, weight loss, uveitis, and  neurological signs.

B. burgdorferi diagnostics include culture, direct microscopic visualization, and polymerase chain reaction, but the most often used  diagnostics are serologic tests such as immunofluorescence assay, Western blot (WB), and enzyme-linked immunosorbent assay (ELISA). The new multiplex bead-based
Lyme test
combines testing by ELISA and WB proteins in a single, quantitative, bead-based assay.

Antibody-based diagnostics makes diagnosis difficult, since it is thought that 60 to 70% of horses in endemic areas may be seropositive. Often owners request Lyme testing for “baselines,” pre-purchase examinations and assistance in determining causes of poor performance, for example. In the equine
borreliosis seropositive horse, it is estimated that a very low percentage actually develop or have signs that may be associated with Lyme disease.

For the complete article:

~ by Rob on October 5, 2011.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: