Security Conscious

Look at where your horse lives. Examine the boundary - is it secure with solid fences and locked gates?
Are there other owners in the vicinity - to create a Horse Watch Group?
Can you carry out or improve on any of the above? At night can the horse be stabled? - the nearer to home the better.

Lights, activated by passive infra-red sensors are a good investment. CC TV is becoming more and more cost effective. If your stables are close to home they can be monitored from the house, or you could install an old LP video recorder at the stables, set to run during the night. This will show you who has been into the yard overnight. This can be achieved for under £200.

If electricity is a problem, go to a car breakers and find an old battery, car horn, a door light switch and an old headlamp. Discreetly connect this up to the gates or even the stable or tack room doors, so that as soon as they are opened lights and noise are activated (remember to fit an isolation switch for the daytime).

It is also possible to modify a domestic alarm system for stable use, but it is important to use door contacts rather than sensors to avoid false alarms. Should your budget allow, you could consider Active Infra-red beams covering the approach to the stables; connected to a radio transmitter they can provide a silent alarm to your house.

Last, but not least, a dog may not be very high-tech, but it is is still very effective!