Reset a models outline for adding a armature

Is there anyway to reset a models outline before adding an armature . I have modelled a horse from a sphere and when I select it in object mode only a few of the veror get highed and not the complete horse, is there a wat to reset the model so the whole object is selected ?

If the model is a single object and you are in object mode then the whole model itself is selected (RMB)

when I select it in object mode only a few of the veror get highed

If you are talking about vertices then these are only visible in edit mode not object mode

As for ALL support questions ALWAYS supply a demo .blend file and annotated screenshots as a minimum so we don’t have to abuse our mind reading abilities or rely on guesswork.