By Dr. Stacy Matthews Branch, DVM
Just as humans can have serious back problems, the same is true of our pups. Many times, we become aware that a back problem exists when a dog is reluctant to walk after jumping off a piece of furniture. Or they may begin to walk differently over time. They may seem to lose their years-long bathroom habits and develop the inability to control urination or bowel movements. Many dogs with these signs may have intervertebral disk disease (IVDD), commonly called a slipped disc. Any dog can develop IVDD, but breeds with long backs and short legs like dachshunds are more prone to develop it.
If you see some of the signs mentioned, limit your dog’s exercise, prevent her from jumping from cars and furniture, take her out for bathroom breaks on a leash, and make the environment comfortable. These measures are important before and after starting treatments to promote the best outcomes and to preserve the quality of your furry friend’s life.
What is IVDD?
The term IVDD refers to intravertebral disc disease. Before answering the title question, however, let’s first review basic vertebral anatomy. The vertebral column is made up of vertebrae connected in sequence along the length of the back. The vertebrae protect the enveloped spinal cord that transmits messages to and from the brain. Branches of nerves from the spinal cord deliver messages to and from the different parts of the body. Any damage from trauma or disease can disrupt the messaging leading to a diversity of dysfunction.
Each individual vertebra is separated from the next by shock-absorbing structures called intervertebral discs. The outer part of the disc (annulus fibrosus) encases the soft, gelatinous inner portion (nucleus pulposus). IVDD develops due to a protrusion or herniation of the gelatinous inner disc material that then presses against the spinal cord (slipped disc).
What are the types of IVDD?
There are three types of intervertebral disc disease (1):
Hansen Type I: There is herniation of the disc in dogs with type I IVDD. The gelatinous inner portion of the disc herniates through the outer layer and puts pressure on the spinal cord.
Hansen Type II: This is a protrusion of the disc itself (outer and inner portions) that leads to compression of the spinal cord.
Hansen Type III: Often called acute non-compressive nucleus pulposus extrusion (ANNPE), this type usually results from a vigorous movement or activity.
Most cases of IVDD are Type I and Type II (the focus of this article) and are seen primarily in the neck and mid to lower back area. Cervical IVDD occurs in the neck region, thoracolumbar IVDD occurs in the mid-back area, and lumbosacral IVDD is associated with the lower back including near the tail base. The clinical signs noted in a dog with IVDD can help significantly in determining the location along the spine that is affected.
What causes IVDD in dogs?
IVDD is often an age-related degeneration of the intervertebral discs; however, many dogs under 7 years of age can develop the condition, particularly dog breeds at higher risk of IVDD development. The degenerated disc can burst or weaken during an activity leading to the herniation or protrusion of disc material against the spinal cord. In cases where there is no degeneration of the discs, a traumatic spinal injury may lead to IVDD.
What breeds are most commonly affected?
Any dog can develop IVDD, but there are breeds that are more susceptible and have a higher incidence of IVDD. Type I IVDD occurs more in chondrodystrophic breeds, that is, dogs with short legs and long bodies (2). The list of dogs in this group is long, but the main breeds that are at higher risk of developing type I IVDD are the Dachshund, Basset Hound, Beagle, Shih Tzu, Lhasa Apso, French Bulldog, Pekingese, and Cocker Spaniel. Dachshunds are at the highest risk with a lifetime prevalence between 20–62% and a mortality rate of 24% (3). Genetic studies show that there is a specific gene associated with premature intervertebral disc calcification and IVDD in chondrodystrophic dogs (3, 4).
Increased risk of type II IVDD has been described in older, large non-chondrodystrophic breeds such as the Doberman Pinscher, German Shepherd, and Labrador Retriever. This type is commonly considered to have a pathology similar to the condition in humans because the outer part of the disc bulges or protrudes and affects the spinal cord. There are instances of type II IVDD in which the inner gelatinous portion leaks out of the inner portion and impacts the spinal cord and the fibrous portion.
What are the signs of IVDD?
IVDD is divided into five stages:
- Dogs with Stage I IVDD typically have mild pain that may be short-lived.
- Stage II IVDD causes moderate to severe pain in the neck or lumbar region
- Dogs with Stage III IVDD can have paresis (slight or incomplete paralysis)
- Dogs with Stage IV IVDD usually are paralyzed but still have sensory perception.
- By the time Stage V IVDD sets in, the dog is paralyzed, can not feel sensation, and is incontinent.
Signs that are often evident in a dog with IVDD pain can include the following:
- Crying out seemingly for no reason and/or shivering
- Arching of the upper or mid-back
- Difficulty of the dog to lift her head
- Neck muscle twitches with light touching of the neck
- Reluctance to walk
- Changes in gait: wobbliness, splay-legged walking, knuckling of the feet, stiffness
At more advanced stages, the dog may be unable to walk at all and develop urinary and/or bowel incontinence. The bladder often becomes very full requiring manual expression or placement of a catheter to empty the bladder.
How is IVDD diagnosed?
IVDD diagnosis is typically determined by the history obtained from the pet parent or caregiver, along with diagnostic imaging. Your veterinarian will likely ask for the time when the onset of signs was noticed and about the progression severity. A neurologic exam will provide additional information such as the location of pain, range of motion, and presence of sensation.
Initial imaging of the anatomical area(s) likely to be the source of the dog’s problem help to determine the state of the vertebral column affected. X-rays are often the first level of imaging to see if there is a narrowing of the disc spaces, if bone spurs are present, or if there is calcified disc material within the vertebral canal (5). Referral to a specialty veterinary hospital may be suggested for computed tomography (CT) or magnetic resonance imaging (MRI, gold standard) for better visualization of the defect and degree of spinal cord compression.
What is the treatment for IVDD?
Medical Management
Management of IVDD may be in the form of conservative (medical) or surgical treatment. The type, stage, and severity of IVDD signs determine what treatment approach would be recommended. Regardless of which approach is chosen, optimal nutrition is crucial to prevent or address excess weight that could place further stress on the vertebral structures. Exercise restriction, usually in the form of cage rest, is necessary for several weeks to minimize pain, prevent the worsening of the dog’s condition, and allow the healing process. Medical management consists of the use of anti-inflammatory agents and muscle relaxants. Adding supplements like Native Pet’s Relief Chews can improve anti-inflammatory processes and promote pain relief, serving as a viable adjunct to the therapeutic regimen.
Although oral non-steroidal anti-inflammatory agents are often used, oral steroidal drugs are also prescribed to lessen spinal cord and related tissue inflammation. An additional analgesic may also be included in the medical treatment plan. Dogs that have a hard time adapting to cage rest may become anxious and can be given anti-anxiety medications and calming supplements.
Surgical Treatment
Dogs who have more severe conditions, who have recurring episodes, or who do not respond to medical management may be considered for surgical treatment. The goal of surgery is to relieve spinal cord compression by removing the problematic herniated disc material. There are various surgical approaches such as laminectomy, hemilaminectomy, laminectomy, and fenestration. Laminectomies involve the removal of a small section of vertebral over the spinal cord to relieve pressure on the spinal cord. Fenestration of adjacent, normal disc spaces during decompressive surgery reduces the rate of recurrent disc herniation at a new location (6).
Surgery Success Rate
Surgery outcomes are the most successful in dogs that can still walk. Available data to date indicates that 90% of dogs who have less than Stage V IVDD fully recover after surgery. This rate decreases as the severity and time after diagnosis increase. Besides the medical status of the dog with IVDD, pet owners also consider the cost of surgery when determining if the surgical approach is accessible. Costs can vary and depend on the approach necessary for a given dog’s condition, ranging from $1,500 to $4,000. Additional costs for monitoring, follow-up, and medications can increase this cost.
Physical Therapy
Physical therapy is a valuable and important part of the treatment of IVDD as part of the medical management approach and post-surgically. A number of rehabilitation practices can be applied, including a range of motion exercises, stretches, muscle stimulation, hydrotherapy, laser, massage, and environmental and lifestyle changes to prevent repeat injury. The goal is to reduce inflammation, pain, and muscle spasms and improve core strength, gait, range of motion, and flexibility to return as close as possible to normal musculoskeletal function.
What is the prognosis for dogs with IVDD?
The prognosis for dogs with IVDD varies on an individual basis because it depends on a number of factors such as the stage of IVDD, the location of the spinal defect, and the severity of clinical signs. Dogs that can’t walk at the time of surgery can also have good prognoses if they still have sensation in the limbs. A fair to good prognosis can be expected in dogs who are treated medically only. This is primarily the case if good pain control is achieved and if their neurologic function is still good. The prognosis is more discouraging in dogs that are paralyzed and without sensation.
How can IVDD in dogs be prevented?
Disc degeneration is difficult to prevent, especially in breeds that are at higher risk of developing the disorder. Nutrition, exercise, and maintaining a healthy weight may help delay the development or prevent progression to more severe forms of IVDD. Dogs that are known to have a higher risk of IVDD development should be prevented from engaging in activities that can increase the likelihood of spinal injuries. Using a harness instead of a neck leash can prevent stress on the neck when walking the dog.
Another way to prevent neck stress is to raise the food and water bowls to allow eating without the need to lower or raise their necks. It is helpful to limit jumping on or off furniture by providing ramps or stairs. At-risk dogs can be monitored and receive exams and imaging periodically to catch problems early to increase the chances of delaying the progression of IVDD.
To read more about your dog’s health and wellness needs, visit the Native Pet blog.
References
- Fenn J, Olby NJ; Canine Spinal Cord Injury Consortium (CANSORT-SCI). Classification of Intervertebral Disc Disease. Front Vet Sci. 2020;7:579025.
- Rusbridge C. Canine chondrodystrophic intervertebral disc disease (Hansen type I disc disease). BMC Musculoskelet Disord. 2015;16(Suppl 1):S11.
- Brown EA, Dickinson PJ, Mansour T, Sturges BK, Aguilar M, Young AE, Korff C, Lind J, Ettinger CL, Varon S, Pollard R, Brown CT, Raudsepp T, Bannasch DL. FGF4 retrogene on CFA12 is responsible for chondrodystrophy and intervertebral disc disease in dogs. Proc Natl Acad Sci U S A. 2017 Oct 24;114(43):11476-11481.
- Dickinson PJ, Bannasch DL. Current Understanding of the Genetics of Intervertebral Disc Degeneration. Front Vet Sci. 2020 Jul 24;7:431.
- da Costa RC, De Decker S, Lewis MJ, Volk H; Canine Spinal Cord Injury Consortium (CANSORT-SCI). Diagnostic Imaging in Intervertebral Disc Disease. Front Vet Sci. 2020 Oct 22;7:588338.
- Moore SA, Tipold A, Olby NJ, Stein V, Granger N; Canine Spinal Cord Injury Consortium (CANSORT SCI). Current Approaches to the Management of Acute Thoracolumbar Disc Extrusion in Dogs. Front Vet Sci. 2020;7:610. Published 2020 Sep 3.