Diseased spinal disks
This painful condition may require surgery
Just as in your own spine, the vertebrae in your dog’s back have cartilaginous discs between them to prevent them from touching each other — (bone-on-bone contact hurts). The spinal cord runs through holes in the center of the vertebrae and above the intervertebral discs, safely protected from harm.
But intervertebral discs can degenerate or be damaged. If the firm outer part of the disc breaks down, the softer inner part can spill out and touch the spinal cord. Because there is limited space in a tunnel of bone, the spinal cord can become pinched, resulting in pain and neurological issues.
But a couple of treatment options can be pursued, depending on the symptoms.
IVDD vs. IVDH
Wood defines the two primary stages of a diseased spinal disc:
Intervertebral disc disease (IVDD)
- The pathology of discs drying out and becoming less functional and more likely to herniate or slip.
- Intervertebral Disc Herniation (IVDH)
- The actual cause of compression to the spinal cord that causes the clinical signs or symptoms.
“Often in veterinary medicine, we use these two terms and abbreviations interchangeably,” says Wood.
But, really, IVDD is when your dog has intervertebral discs that could become a problem, and IVDH is when one or more discs are causing problems.
What you see
“For many animals the first and sometimes only sign is pain, reluctance to move their head or neck, or standing hunched and crying when picked up,” says Wood. “Other animals may have trouble walking, where their feet slide out, they walk on top of their feet, or trip and fall frequently. In severe cases, they may not be able to move their legs at all.”
Depending on where the problem is and how the disc presses against the spinal cord, only one leg may be affected, or the dog might walk well but have neck pain. Imagine your dog as a puppet, and the strings that work the legs are the spinal cord — if you get the strings tangled, the puppet won’t move properly anymore.
“Sometimes pain and reluctance slowly progress to trouble walking and then not walking at all over days or weeks; otherwise, sadly, dogs that were a little off in the morning are not able to move by the afternoon. There is a lot of variation, and we can’t predict well each time which patient is going to be a slow progression or a quick one,” says Wood.
“If the pet seems uncomfortable, is standing funny, or you hear toenails dragging or scuffing as they walk, those are good clues that there is a problem with the spinal-cord function and that they should at least contact a vet right away,” he says.
Getting a diagnosis
Pain or neurological symptoms alone aren’t enough to make a diagnosis of disc disease. Other conditions that can have the same symptoms include soft tissue injury, infections, autoimmune problems and even cancer. Your veterinarian will start with a physical exam, a detailed history of the dog's behavior and symptoms, bloodwork to start ruling out other causes, and then they will likely take some X-rays.
“We can’t diagnose disc issues just on X-ray,” says Wood.
Magnetic resonance imaging (commonly called an MRI) is the diagnostic tool of choice, especially for patients with severe symptoms or who have mild symptoms that don’t respond to treatment. This is offered at the Cornell University Hospital for Animals (CUHA).
Choosing a treatment plan
The two main treatment options are medical and surgical. Medical management is the conservative choice and often the most attractive initially. “Here the clinician chooses a variety of medications that usually include an anti-inflammatory, one or more pain medications, and strict bed rest — where the patient is not allowed to run, jump or play outside of its crate or small room for 4-6 weeks while healing occurs,” says Wood.
“The other option is surgical management, where we go in and remove the compressive disk material that is pushing up on the spine," he says. "After surgery, they are usually in the hospital for a few days, and then go home with similar medications, and for the same amount of cage rest."
Your dog’s condition will likely make the treatment plan decision. “In general, here in CUHA Neurosurgery we like to move to surgery sooner since that has a potentially better outcome, and also a lower rate of future problems,” says Wood. For example, once a herniated disc has been addressed with surgery, it is unlikely to cause trouble again.
“When patients are still walking, medical and surgical outcomes favor a benefit to surgery, but medical management still has good outcomes. As patients get more severe signs, then the benefit of surgery over just medication grows,” he adds.
If your dog is showing severe symptoms, such as inability to move one or more legs, moving quickly is essential. Surgery performed within 24 hours of loss of deep pain sensation in the leg has a 90% success rate with the dogs getting back to normal mobility and activity after recovery. The longer the dog has lost feeling, the worse the prognosis. Dogs who have had chronic long-term signs may also have a limited or more constrained prognosis.
Many owners of dogs with mild symptoms choose to try medical management first. This is a good time to do a little research into surgical options near you. If your dog does well and improves with medication and rest, then there is no harm done.But if they do rapidly deteriorate, you will be prepared with a plan to pursue surgery quickly.
This article has been reprinted with permission from the Cornell University College of Veterinary Medicine’s DogWatch newsletter, published by Belvoir Media Group. When you become a member of the Riney Canine Health Center, you will receive a free subscription to DogWatch.