A method of preparing an antibody suitable for use in an equine is provided. Also provided are equinised antibodies which specifically bind to equine neuronal growth factor (NGF) and neutralise the ability of equine NGF to bind to the p75 or TrkA equine NGF receptor. The invention extends to nucleic acids encoding same and to methods of treating pain and arthritis in an equine using said antibodies and/or nucleic acids.