For several years now, all horses in the UK have had to be microchipped by law, except for a few special exemptions.
But how safe and reliable is this system? Should we be worried about injecting a permanent solid object, however small, into the necks of our horses? Do the chips cause any tissue reaction, or do they irritate?
In an attempt to answer these questions, vets in Austria and Germany studied the tissue immediately surrounding the microchip in horses undergoing post-mortem examination for unrelated reasons.
Microscopic examination revealed that the chips were well tolerated, whether they were implanted into fat, muscle or neck ligament, with most horses showing no adverse reactions. The horse’s body produced a thin, fibrous capsule to surround the chip, with no sign of inflammation.
The team then tested the accuracy of the system in identifying 428 horses of all types, ranging from ponies to large draught breeds.
Provided the chips conformed to international standards, they responded as they should. But significant variation was detected in the ability of the scanners to read them. As might be expected, the bigger, more expensive scanners easily outperformed the smaller, cheaper ones.
The vets concluded that microchips are safe, reliable and painless. Where one scanner suggests that a horse is not chipped, however, they recommended trying another before a chip is inserted.