Objective—To determine the effect of a static magnetic
field on relative blood flow to the metacarpus of
Design—Randomized controlled clinical trial.
Animals—6 healthy adult horses.
Procedure—Red blood cells were radiolabeled in vivo
by administration of technetium Tc 99m (pyro- and
trimeta-) phosphates, and scintigraphic images were
obtained 30 minutes later. A magnetic wrap that emitted
a static magnetic field was applied to 1 metacarpus
and a control wrap was applied to the contralateral
metacarpus. Forty-eight hours later, the wraps
were removed, and scintigraphy was repeated.
Relative perfusion ratios were calculated by dividing
mean count per pixel for the portion of the metacarpus
under the wrap by mean count per pixel for a portion
of the distal aspect of the antebrachium that was
not in the magnetic field.
Results—The difference between the relative perfusion
ratio prior to application of the wrap and the ratio
after application of the wrap for limbs that received
the magnetic wrap was not significantly different
from the difference in ratio for limbs that received the
Conclusions and Clinical Relevance—Results suggest
that in horses, the static magnetic field associated
with application of commercially available magnetic
wraps for 48 hours does not increase blood flow to
the portion of the metacarpus underneath the wrap.(J
Am Vet Med Assoc 2000;217:874–877)