For a routine surgery such as ovariohysterectomy, a leash walk only until sutures are removed is the general recommendation. (blog.nhvnaturalpetproducts.com)
This procedure is called ovariohysterectomy for the female (i.e. - removal of the ovaries and uterus, or spaying), and castration for the male (i.e. - removal of the testicles, or neutering). (bestfriendsvethosp.com)
Most vets will push for ovariohysterectomy as a first solution, but mostly only during the beginning of pregnancy (i.e. the first month.) (breedingbusiness.com)