What is a Herniated Disc?
The intervertebral discs (the cushion in the space between the bones of the spine) of dogs have conditions and forces that can make them swell or rupture over time. This rupture, also known as a herniated disc, ruptured disc, or intervertebral disc disease (IVDD), leads to two types of damage to the spinal cord: compression and concussion. The extent of the damage is determined by:
- Type of force
- Degree of force applied to the spinal cord
- Length of time that the force was applied
Dogs may have minor spinal cord damage if their owners notice a loss of coordination or a “drunken sailor” type of walk. Damage that is more significant leads to loss of walking or moving the legs and potentially a loss of pain sensation. A dog’s recovery can be affected depending on the length of time they may have been suffering.
Chondrodystrophoid breed dogs (Dachshund, Pekinese, Beagle, Lhasa Apso, etc.) account for the majority of all disc ruptures, with the Dachshund accounting for 45–70 percent of all cases. In these dogs, owners may notice clinical signs between three and six years of age, however, disc calcification (or hardening) can occur as early as two-years-old. Nonchondrodystrophoid dogs (Labrador Retrievers, German Shepherds, etc.) may show signs between five and twelve years of age.
How to Tell if your Dog is Suffering from a Herniated Disc
Herniated discs can lead to several different degrees of pain; however, when nerve damage starts to develop and progress, it follows a predictable pattern:
- Back or neck pain, refusing to walk or look around the room.
- “Drunken sailor” walk or wobbly in the back legs, hind feet will often cross as the pet steps.
- Complete loss of hind limb motor function. Usually, at the same time, the pet loses the ability to urinate.
- Reduced-to-absent perception of pain, which is a sign of severe cord injury that can carry a more serious prognosis.
Most primary care veterinarians may suggest an initial health screening, as well as any of the tests listed below:
- Blood work: complete blood count (CBC), serum chemistry, and a urinalysis
- X-rays of the spine or chest
An ACVS board-certified surgeon may be contacted to assess the case and determine the set of appropriate tests for the patient. Based on the neurologic examination, herniated discs are generally grouped into large regions, called neurolocalization, which helps to plan which tests and surgeries may be offered.
- An X-ray series where a needle injects dye around the spinal cord to highlight any compression, known as a “Myelogram” (Figure 1)
- CT scan instead of or after the Myelogram
- Magnetic resonance imaging (MRI) study in addition or instead of a CT scan
- Spinal tap at the same time as the imaging
Depending on the degree, treatment can consist of anything from crate rest and pain medication to multiple surgeries and/or procedures. A consultation with a primary care veterinarian can help owners fully explore all available options. Surgical decompression (pressure reduction) of the spine by removal of the bone over the spinal canal is nearly always recommended (Figure 2). Some cases may call for emergency surgery.
A consultation with a primary care veterinarian can possibly diagnose the problem and determine if surgery is required.
What to Expect After Treatment:
Most pets can leave the hospital or clinic three to seven days after surgery. They are usually returned for check-up and removal of stitches or staples (if present). Pain can be well controlled with prescribed medications given by the owner.
The following may be necessary or present following treatment:
- Urination three-to-four times daily
- Physical rehabilitation for muscle strength and flexibility
- Exercise restriction to “bed rest” for at least four weeks
Lifestyle changes may include weight loss, switching to a body harness instead of a collar, and minimizing jumping off furniture.
Complications after surgery can include:
- Seizures from the Myelogram in the first 24 hours after the procedure
- Infection at the surgery site
- Another disc herniated later in life
- Continued wobbly walk or dragging hind toes when walking
Results will differ depending on the degree of injury and the location of the injury. Most disc ruptures in dogs that are still able to walk have an excellent chance to return to walking. However, if the pet has lost the ability to sense pain in their legs before surgery is performed, the pet may never walk again.
Left untreated, herniated discs can lead to permanent loss of the ability to walk. Most dogs that reach this point will also lose control of their bladder and are at risk for chronic urinary tract infections and urine scald (irritated skin in the area). Additionally, without motor function, patients may have limited movement and may develop bedsores and wounds as a result.
If you have concerns about your dog, and you need to locate a board-certified veterinary surgeon, use the VetSpecialists.com search tool on the website’s homepage. The tool allows you to search for a veterinary specialist, then select the type of animal along with your location by zip code or city name. Contact the hospital of your choice to discuss your pet’s signs and to review whether there is a need for a referral from your primary care veterinarian.