Dogs with a slipped disc that can't walk, or have difficulty walking, are cases that certainly cause great concern to many dog owners.
Affected dogs develop severe back pain, and possibly, difficulty walking.
The medical term for disc disease is Intervertebral Disc Disease, often abbreviated as IVDD.
Some dog breeds are more predisposed than others. In this article, veterinarian Dr. Eric Weiner discusses the diagnostics and treatments for dogs suffering from IVDD.
A Dog With a Slipped Disc That Can't Walk Properly
A client comes into your clinic with their middle aged Dachshund presenting with sudden back pain. This owner just noticed their dog was reluctant to walk and slightly shuffling his back feet as he walks (but can walk on his own).
He has no history of back issues, and was last normal with a good appetite last night. He is not on any current medications other than routine heartworm, flea and tick prevention. What do you do next?
A complete physical exam revealed a quiet, but alert and responsive dog with minimal dehydration.
His temperature, pulses, and respiratory rate are all within normal limits. Abnormalities detected on physical exam included the dog tensing when you palpate his belly and pain elicited when you palpate his back (the normally sweet dog tried to bite you!). You wonder, is this a musculoskeletal or neurologic problem?
Next is the orthopedic and neurologic exams to find out.
Looking at his face, you determine all his cranial nerves are normal. Next while supporting most of his weight, you place each foot, one at a time, over and see if the patient will flip it back over on its own. This is called conscious proprioception, and it tests to see if the dog knows where it’s feet are in space.
The front feet are corrected immediately, while there is a bit of a delay in the back legs. After testing a few other motions with the front legs, you determine they are completely sound and neurologically appropriate. However the back legs do drag slightly when lifting his front half up and watch him walk backwards on his hind legs.
Next you evaluate his neck for pain and range of motion. He can look all the way up and down, and can touch his nose to his side in both directions without a problem. Then you press along his spine. He reacts in pain when you get towards his mid-lumbar (towards the back) of his spine.
Your assistant then gently places him on his side so you can check reflexes. His reflexes in the front legs are completely normal The back legs are normal to slightly hyper-reflective (over active). You have confirmed back pain with mild neurologic deficits. Now what?
A Case of Intervertebral Disc Disease (IVDD)
You have a discussion with the owner of your findings. You discuss how you suspect disc disease, as Dachshunds are the poster children for this problem. Disc disease, or more properly called Intervertebral Disc Disease (IVDD), occurs when the disc, or cushion and shock absorber between the building blocks of the spine called vertebrae, pop or herniate into the spinal canal.
This can either cause a contusive injury, like a bruise, or a compressive one, injuring the spinal cord. This causes pain and interferes with the sensory (feel) and/or motor (movement) function. Causes include trauma, overload (i.e. obesity) or age-related degeneration (Tilley and Smith JR, 2016).
Clinical signs can range from lethargy and inappetence, to reluctance to walk and weakness (paraplegia) or complete paralysis, or even urinary bladder dysfunction. This is very variable based on location or locations of lesion(s), and extent and duration of the injury.
What Does a Hard Stare Mean in Dogs?
A fixed, hard stare in dogs is something to be aware of. You may notice it in some specific situations where your dog is particularly aroused by something. Pay attention to when it happens so that you can take action, even better, intervene *before* your dog shows a fixed, hard stare.
What is Fear Generalization in Dogs?
Fear generalization in dogs is the process of a new stimulus or situation evoking fear because it shares similar characteristics to a another fear-eliciting stimulus or situation. This may sound more complicated that it is, so let's take a look at some examples of fear generalization in dogs.
Other possible causes in this case that should be considered include spinal fracture, discospondylitis, fibrocartilaginous embolism (FCE), and cancer. A fracture can certainly impede the function of the spinal cord, but can be ruled out with x-rays. Discospondylitis is an infection of the disc and surrounding structures.
FCE can present very similarly to IVDD, but typically does not progress beyond 24 hours and usually resolves on its own. Depending on the type of cancer, a tumor can be within the nerves of the spinal cord itself, or within the surrounding structures, putting extensive pressure against the spinal cord.
Other Diagnostic Tests
A neurologic exam in conjunction to history should help localize the lesion within the central nervous system. Typically survey x-rays are taken to look for broken vertebrae or misalignments within the spinal cord.
Normal disc material does not show up on x-rays very well, thus this is not the best modality for the evaluation of disc disease.
It is however much more readily available and less invasive than more advanced diagnostics, such as MRI and CT scans. The diseased disc may be mineralized in chronic cases, which may show up radiographically.
Another radiographic telltale sign of IVDD is disc space narrowing. This is the vertebral bodies at the lesion are much closer together when compared to the vertebrae throughout the rest of the spine.
You take x-rays of your patient and you see some disc space narrowing between the 4th and 5th vertebrae within the lumbar (lower) spine.
Medical Management or Surgery?
How do you treat, doctor? There are essentially two options within a general practice: medical management or referral to a specialist. In this case the dog has deep pain sensation and can walk, albeit weak and wobbly. Medical management would be reasonable.
Medical management focuses on pain relief, anti-inflammation, muscle relaxation, and STRICT activity restriction for several weeks. Depending on how the dog responds to therapy will determine if further management or referral is needed. Most (up to 95 percent) of dogs that are acutely painful with minimal neurologic effects respond well to medical management.
The cases that warrant specialist attention, and possibly surgical correction, include the dogs that have no deep pain sensation (no reaction when their toes are pinched) and are completely down (paralyzed) or those that fail to respond to appropriate medical management.
Neurology specialists will perform another neurologic exam and possibly recommend further testing such as MRIs, CTs, or take a small sample of spinal canal fluid for cytology via cerebrospinal fluid tap. From there, they will make the decision on whether or not the patient is a good surgical candidate, which procedure to perform, and where to cut.
Immediate surgery for dogs that have no deep pain sensation has a 50 percent success rate. Medical management in these cases would be inappropriate and considered malpractice.
It is possible that clinical signs recur, more often without surgery, or can occur at different sites, depending on the underlying cause. Steps that may diminish the chances of recurrence include sufficient rest during initial flare up, avoiding jumping on and off furniture and stairs, and weight loss to lessen the load or stain on the back.
Your patient responded beautifully to medical management, and after several weeks is back to normal. Good job!
Tilley, Larry P. and Smith JR, Francis W. K. Blackwell’s Five Minute Veterinary Consult: Canine and Feline. Sixth Edition. Wiley Blackwell. Intervertebral Disc Disease, Thoracolumbar. pp 763-765.