Microchipping is only really useful if your horse wanders. It's not compulsary for the vet to check a 'new horse' for microchips and as far as I know they don't scan them at auctions, if a stolen horse was even to see the light of day at one.
Freezemarking seems to be the only way to go, but even these are often covered by rugs which takes away the visual deterent.
Put a file together of photos of your horse taken from both sides, and with winter and summer coats. Include in the file a list of emergency phone numbers, police, Horsewatch groups, port authorities, auctioneers and abbatoirs.....and keep the file somewhere you'll know where it is if you need it.
Chat to any neighbours near your yard, give them your number to call if they see or hear anything suspicious.
Vary the hours that you go to the yard, don't stick to a routine that the thieves could be sure of.
Be suspicious of any unknown woman and child combination taking an interest in your horses, the thieves will use them to check out your horse and yard.
Be aware if your horse seems unusually sleepy, he could have been sedated prior to being stolen as it makes them easier to load....it DOES happen!!
If your are waiting for your horse to be freezemarked but are particularly worried in the meantime, completely purple spray one or more of your horse's legs. Yep, it's going to look very silly but it's better to have a purple legged horse than no horse at all.
We work on the basis of trying to make the criminals make as much noise as possible whilst trying to steal things.
As a result, our field, yard, trailers and shooting ground have multiple locks, chains and things to make it as awkward as possible.
Turning one gate hinge upside down prevents the gate being lifted straigt off, bolts through the hinge also help. Chains and locks at both ends of the gate are something else that has to be cut.
A random pattern of events at the venues help. We will at random visit to check things, repair things and have no pattern you could set us to.
Contact with the local police are also beneficial.
we have the annual Pikey-fest also known as Priddy Fair just down the road from me...
i have coloured's, live on an A Road en-route..i worry but put in motion EVERY year a plan..
all ponies are hidden away..by that they are put in the back field away from eyes..
and the coloureds are shut away, in the barn for the week leading up to and 4 days after Priddy....