Before your dog undergoes surgery for a herniated disc, you've likely gone through the "conservative" treatment route unsuccessfully and saw your pet go through a lot of pain. With good care and luck, he should regain mobility after surgery, but it requires more than a month of recuperation and therapy.
Your dog underwent an operation known as a hemilaminectomy. The Michigan Veterinary Specialists website describes the procedure as "removing a portion of bone from one side of the back bones at the level of the herniated disc." Once the spine is open, the material from the herniated disc is removed from under spinal cord. The surgeon might also perform fenestration to prevent a future disc issue. This involves opening adjacent disc sides and removing gelatinous material.
It's likely your dog will remain in the veterinary hospital for at least a week after surgery. Much depends on how quickly your pet regains the ability to urinate on his own. Once your dog is home, his activities are severely limited for the next four to six weeks. Restrict him to a part of the house where he can't climb stairs or attempt to jump up on furniture. If you have other dogs, keep them away from him so they can't start playing or fighting. You can take your dog for brief walks so he can take care of business, but he must always be on a leash. Don't let him out into a fenced yard off-leash, even if you're supervising him.
Your vet will prescribe various medications to help your dog during his recuperation. She might prescribe nonsteroidal anti-inflammatories for pain relief, along with steroids to ease inflammation and swelling. You'll need to check your dog's incision regularly. If there's any sign of infection, such as swelling or pus at the site, your vet might prescribe antibiotics to combat it.
You can begin physical therapy soon after your dog comes home. Conduct these exercises several times daily according to your vet's instruction. A veterinary physical therapist will show you how to flex your dog's rear legs, along with extending the joints. You'll also move your dog to a standing position, keeping him there for a few minutes until he tires out.