The vertebrae or backbone are a series of bones that support and protect the spinal cord. In between these vertebrae are disks that cushion the bones and act as spacers between the vertebrae. These disks can herniate or protrude into the spinal column causing pain and neurologic deficits. This tends to occur in middle aged to older, small, long back breeds. The most overly represented breed is the dachshund, but this syndrome can occur in all breeds including the larger breeds. We see an average of 3 cases a week in our practice.
The clinical signs can range from mild back pain to complete paralysis. Typically a dog will present with the complaint that it is not jumping up on the couch as usual, and cries when picked up. Often the owner will say their appetite is less and they may be reluctant to “go to the bathroom.” This occurs because the back and neck are painful and the dog is reluctant to bend to eat, or assume the position to defecate or urinate. On the physical examination there may be conscious proprioceptive deficits, weakness especially in the rear legs, and pain when the neck is manipulated or the back palpated. CP deficits are documented when the toes are turned with the topside down. The dog should immediately right the foot to the proper position. A delay signifies and interruption in the signal from the foot to the brain. More serious clinical signs include dragging the rear legs, crossing of the rear legs when walking, and a frog legged stance.
Diagnosis is made on clinical signs, and occasionally with radiography. The more serious cases are referred to a veterinary neurologist who will perform myelograms, or an MRI to identify the exact location of the herniated disk.
Treatment depends on the severity of signs. Early cases are treated with cage rest and steroids or non-steroidal anti-inflammatories, muscle relaxants, pain medication, and intravenous polyethylene glycol. We have a therapeutic laser machine that is a wonderful treatment modality. The light laser is anti-inflammatory, and relieves pain. This is also used post surgery to speed up recovery. A study at the University of Florida College of Veterinary Medicine showed that paralyzed dogs that received post operative laser therapy walked an average of 5 days post op versus dogs that didn’t that walked an average of 17 days later. There are no side effects and we use it extensively in the treatment of iv disk disease. Surgery is recommended by a board certified neurologist if there is significant paresis or weakness in the legs, or if the dog is very painful and does not respond to medical treatment. Prognosis depends on the severity of the herniation, how soon after the occurrence of the disk herniation the dog is seen by a veterinarian, and how aggressively the dog is treated. Surgery involves removal of the disk, and occasionally making a window in the vertebrae to make room for the disk material.
Prevention entails keeping the dog physically fit, as overweight dogs have a much higher incidence of intervertebral disk disease. I try to discourage clients with predisposed breeds to allow them to get on couches and beds as puppies. It is much easier to train them not to do this than to try and keep them off a bed after the condition develops.