An article in the 'Horse and Hound' in January 2014 'Joint Problems: Are they on the rise?' included:

Pippa Funnel (Olympic event rider and breeder): 'Religiously every Monday we have physio...'Will Funnel (International show jumper and sport horse breeder): 'If we see changes, we work with vets and our physio'Andy Bathe (vet and partner at Rossdales specialising in surgery and orthopaedics): 'So the take home message, especially with older horses, is regular monitoring' 
As I've been saying for a while now, physio is as much about monitoring and prevention as about fixing problems.  It’s great to hear such well respected professionals letting the general public know some of what lies behind their success. Regular turnout, different surfaces, a variety of work, daily checks, prompt treatment of minor ailments, careful attention to detail, correctly fitting and appropriate tack; these and so much more are important aspects of maintaining your horses body and promoting a long and comfortable working life. 

My personal recommendation with regards to physio is every month for competition horses to promote optimal performance, and every three months or so for 'Riding Club level' horses who are ridden 4 or 5 times a week and competed occasionally, to maintain comfort and performance and to check for any problems that might be developing. Then every six months or so for horses who are lightly hacked, to flag up any concerns and to get to know the horses 'normal' patterns in order to recognise when something isn't right.

To find your local Chartered Physiotherapist visit www.acpat.co.uk.
Image to the right copyright Simon Palmer