Sorry to hear about your horse. Just to clarify the situation on physios/chiropractors/osteopaths etc. You must get a referral from you vet, and not go directly to the physio etc. The vet must be responsible for the treatment given, and only a vet can give a diagnosis and give treatment. This is...
To make owners aware, you need to be referred to a physiotherapist/osteopath/chiropractor via your vet, and the treatment must be under the direction of the vet, according to the Veterinary Act 1966:
Physiotherapists, osteopaths and chiropractors
19.12 The Veterinary Surgery (Exemptions)...