My horse is vaccinated for Lyme and has been for the past 3 years.
I only trail ride, am in MA and am constantly pulling ticks off.
Here’s his test results from May 2020 with the explanation.
To summarize, high OspA with low OspC and low OspF means the good antibodies.
High OspA and high OspC or OspF potentially means infection.
Lyme Dis. Equine - Multiplex The Lyme multiplex assay determines antibodies to three antigens , called ‘outer surface proteins (Osp)’, of B.
burgdorferi which have been shown to correlate with vaccinal antibodies, or acute and chronic stages of Lyme disease.
Negative: Negative values for antibodies to all three Osp antigens are predictive that the horse is not infected. If only one or two values are in the negative
range see interpretation for equivocal or positive values for the corresponding Osp antigen.
Equivocal: Equivocal values can indicate very early infection or can be induced by non-specific serum reactions. If there are no positive values for any of the
three Osp antigens, the horse should be retested in 2-3 weeks to confirm or exclude early infection. If one or two values are in the positive range see
interpretation for positive values for that corresponding Osp antigen.
Positive/ OspA (>2000 - 28,000): Positive values for antibodies to OspA are typically observed in vaccinated animals . In horses, however, antibodies to OspA
also seem to rise during infection. Thus, the interpretation of results on antibodies to OspA is more complex in horses . If antibodies to OspC and/or OspF are
positive, along with OspA, the horse should be considered as infected with B. burgdorferi.
Positive/OspC (>1000 - 10,000): Positive values for antibodies to OspC only are indicative for early infection. Antibody values to OspA can also be elevated
during early infection.
Positive/OspF (>1250 - 26,000): Positive values for antibodies to OspF only are predictive for chronic infection stages. Positive values for antibodies to OspC
and OspF in the same sample are indicators for an infection that occurred several weeks ago and is moving towards the chronic infection stage.
FOR ADDITIONAL INFORMATION: http://ahdc.vet.cornell.edu/docs/Lyme_Disease_Multiplex_Testing_for_Horses.pdf and
This assay is validated and accredited for the detection of antibodies to three Borrelia burgdorferi antigens in equine serum