Your dog is yelping in pain, and you notice that he is having trouble moving his back legs. Intervertebral Disc Disease (IVDD) is a “slipped disc” in the spinal column that can result in excruciating pain and possible paralysis due to compression of the spinal cord. Certain dog breeds are predisposed to this neurological ailment, such as Dachshunds. The Meowing Vet discusses why IVDD may occur in dogs or cats, other signs that pet owners should be aware of, and how this problem is diagnosed and treated.

Learn more below…

The Spine

The spine (or spinal column) is comprised of a vertical arrangement of vertebrae (or vertebral bodies), a series of bones that surround and protect the spinal cord. The canine spinal column is made up of 7 cervical (or neck, C1-7), 13 thoracic (or chest, T1-13), 7 lumbar (lower back, L1-7), 3 sacral (pelvic region, S1-3), and multiple coccygeal (a.k.a. caudal, or tail) vertebrae. Squishy discs of cartilage called intervertebral discs lie between each vertebrae (excluding between cervical vertebrae 1 and 2 as well as between vertebrae of the sacrum, which are fused together). These discs act as shock absorbers while also piecing together the individual vertebral bodies of the spine. Each spongy intervertebral disc is comprised of a gelatin-like center called the nucleus pulposus (this region lacks a nerve and blood supply) surrounded by a fiber-like band called the annulus fibrosus. (This specific anatomic arrangement will come into play later on as we discuss the causes of intervertebral disc disease, or IVDD.)

The spinal cord, along with the brain, make up the central nervous system (CNS). The spinal cord acts as the “vice president” of the governing brain, transmitting the brain’s messages via nerve impulses to the rest of the peripheral body. Nerves branch off the spinal cord at specific nerve root locations in order to provide nerve supply (i.e. innervate) various regions of the body, primarily the limbs. If a certain area of the spinal cord is injured (as occurs with IVDD), approximately everything “downstream” from that location is therefore unable to receive the proper signals (nerve impulses) from the brain in order to function properly. Therefore, the limbs will not work normally.

This type of spinal cord injury is exactly what happens with intervertebral disc disease, or IVDD: injury to one (or several) of the intervertebral discs results in compression of the spinal cord, causing pain as well as “downstream” nerve dysfunction.

Causes of IVDD

Intervertebral disc disease is the most common cause of spinal cord disease (a.k.a. myelopathy) in dogs. It occurs due to progressive damage to the intervertebral disc over time due to a variety of factors, including genetics, sudden traumatic injury, and/or chronic low-grade injury over time due to abnormal stress on the spine. Such injury interferes with the cartilage composition of the disc, leading to dehydration and calcification (or mineralization) as well as impairment of its nutritional supply (which is already limited due to poor blood supply to the center of the disc, thereby interfering with healing). These changes cause the disc to be hard rather than spongy. Eventually, the damage to the disc is so great, that it eventually fails, leading to an IVDD problem.

Any region of the spine may be affected, though the area between the 3rd thoracic vertebra and 3rd lumbar vertebra (T3-L3) are most commonly affected (primarily between T10-L2 as anatomic differences in this region cause the spine to be more unstable here, and therefore more prone to abnormal movement). IVDD may arise primarily from one of two scenarios: Hansen Type I Disc Degeneration or Hansen Type II Disc Degeneration.

Hansen Type I Disc Degeneration results in rupture of the annulus fibrosus, causing sudden extrusion of the nucleus pulposus through this tear. The prolapsed material then pushes up against the spinal cord and/or nearby nerve roots, causing the “downstream” nerve dysfunction (and pain!) that we mentioned prior. This herniation (i.e. herniated, or slipped disc) occurs due to dehydration and calcification (chondroid metaplasia, to be technical) of the intervertebral disc over time secondary to the factors addressed previously. This type of IVDD is generally acute (or sudden) in nature.

Hansen Type II Disc Degeneration occurs due to dehydration and thickening of the annulus fibrosus (i.e. fibrinoid metaplasia). Because the annulus fibrosus is so thick, an outer tear does not  typically occur, so the nucleus pulposus does not spill through it to infringe upon the spinal cord directly. Instead, a protrusion (or bulge) of the inner nucleus pulposus gradually pushes up against the surrounding annulus fibrosus band onto the spinal cord without a rupture of the band actually occurring. (Sometimes, however, the annulus fibrosus does tear, resulting in a flap that also compresses the spinal cord.) Though some cases of Type II IVDD may be acute, most are chronic, meaning you will likely note progressive worsening of your pet’s mobility and comfort. Type II IVDD typically affects discs between the 6th cervical vertebra in the neck and 2nd thoracic (chest) vertebra (C6-T2). This type of IVDD is a component of cervical spondylomyelopathy (Wobbler’s disease) and degenerative lumbosacral stenosis.

These two types of IVDD are only truly differentiated via histopathology of disc material obtained during surgical treatment.

What Dog Breeds Are Most At-Risk?

While many older cats may experience chronic IVDD, the presence of clinical signs due to this neurological disorder is more common in dogs. In the veterinary community, we term such patients suffering from IVDD “back dogs”.

Though some younger dogs may be affected by IVDD, most cases occur in dogs over 2 years of age. Most dogs that sustain a Hansen Type I injury are between 2-6 years of age (though this problem can also be seen in older dogs as well). The following dog breeds have a higher genetic predisposition to developing Hansen Type I Disc Degeneration versus other breeds:

• Dachshund (“wiener dogs”): Dachshunds are the poster child for IVDD. Doxies are termed a “chondrodystrophic breed” due to their long backs (and short legs). Along with a genetic predisposition to sustain degenerative changes within an intervertebral disc, their disproportionately long back to body ratio causes instability in their spine. Approximately 20% of Dachshunds (1 in 5) will experience IVDD at least once in their lifetime, and of those affected, 20% will later sustain another IVDD injury.
• Other chondrodystrophic breeds:
  • English and French Bulldog
  • Corgi
  • Pug
  • Chihuahua
  • Terriers
  • Pekingese
  • Lhasa Apso
  • Shi Tzu
  • Miniature Poodle
  • Beagle
  • Bassett hound
  • Cocker spaniel
• German shepherd
• Labrador retriever
• Rottweiler
• Doberman
• Weimeraner

Any dog breed may experience Hansen Type II Disc Degeneration (i.e. no particular breed is more likely than another to sustain this type of IVDD injury). Due to the typically chronic nature of this disease, most of these dogs are older when they first exhibit outward signs of a problem.

What about Cats?

As mentioned, many older cats may have chronic IVDD. In fact, nearly all cats over 15 years of age are affected with Hansen Type II IVDD. However, most of these cats are subclinical, meaning they rarely display the same dramatic clinical signs as do dogs. In some circumstances, acute clinical signs do arise, and these cats may require surgery. If the cervical spine (or neck region) is affected, however, surgery on this region should be avoided in felines, as it carries a high mortality risk. (Learn more about prognosis of IVDD below.)

Some kitties may also experience an acute Hansen Type I disc herniation, primarily caused by trauma and arising in the lumbar region of the spine. Surgery may be a better option for this type of IVDD since cats do not tend to fare as well as dogs do with conservative medical management alone. (Read more about treatment options for IVDD below.)

Clinical Signs of IVDD

The clinical signs of IVDD may somewhat differ depending upon the velocity at which the disc impacted the spinal cord, the amount (or volume) of compressing disc material, and the amount of time that material has pushed up against the spinal cord. The most common signs that your dog or cat may be suffering from intervertebral disc disease include:

• Pain
  • Pain may derive from either the injured disc, nerve roots, meninges (the protective tissue around the spinal cord), intervertebral joint, or ligaments or outer covering of vertebral bone (periosteum). Dogs and cats with IVDD may also suffer from painful muscle spasms.
  • With acute injury (primarily Hansen Type I), pain arises suddenly and is usually very alarming to pet owners due to its intensity. These pets will often cry out and howl in agony. Pain control is a top priority for these dogs and cats, so get your pet to the nearest veterinary clinic ASAP!
  • With chronic IVDD (generally Hansen Type II), your pet may not suddenly yelp out in pain, but you may observe him or her walking slowly with a hunched posture or with his or her neck down; such pets may groan in discomfort upon rising or lying down and may exhibit behavioral changes (acting grumpy or disinterested in activities previously enjoyed; appetite may also decline).
  • With more severe cases of IVDD, pets may actually progress to being imperceptible to painful stimuli below the level of the spinal cord injury. For lack of a more sophisticated phrase, THIS IS BAD! Loss of sensation to deep pain carries a poor prognostic outlook (read more about IVDD prognosis below).
• Mobility problems: Because nerve roots that travel to the legs branch off the spinal cord, any nerve caudal to (or behind/below) the area of the spine affected by IVDD may be disrupted. This results in abnormal movements to the limbs. The effects on mobility (or ambulation) will vary depending upon the severity of the spinal compression. Such problems include:
  • Conscious proprioception (or CP) deficits: Conscious proprioception is your dog and cat’s ability to innately know where their limbs are in space. Nerve impairment may cause CP deficits ranging from knuckling (instead of your pet’s paw pad being flat on the ground underneath him, he has it turned over and may drag it on the ground when walking, resulting in skin abrasions) to not knowing to lift up a limb appropriately prior to bumping up against a surface.
  • Ataxia: Uncoordinated movements. You may notice your pet walking as if drunk or unintentionally crossing his or her legs when walking.
  • Paresis: Weakness. Depending on the degree of weakness in your pet’s front and/or back legs, he or she may be unable to walk.
  • Paralysis: Being unable to move either the back legs or all four legs — paraplegia and tetraplegia (or quadriplegia), respectively. Tetraplegia can occur due to spinal injury occurring between the 1st cervical vertebra in the neck and the 2nd thoracic vertebra in the chest region (C1-T2). Conversely, paraplegia occurs due to injury to the spine sustained between the 3rd thoracic and 3rd sacral (or pelvic) vertebrae (T3-S3).
• Bladder problems: Nerves that innervate the bladder are often affected by IVDD. Depending on the location of the IVDD in the spine and which nerve is affected, a dog or cat may experience what is known as either an upper motor neuron (UMN) bladder or else a lower motor neuron (LMN) bladder. With these conditions, the affected animal cannot normally empty the bladder (i.e. urinate). Not only do these conditions cause an animal to be uncomfortable, but such disorders also lead to recurrent or persistent urinary tract infections (UTIs).
  • Upper Motor Neuron (UMN) Bladder: Nerve impairment cranial to (above or before) the level of the 4th lumbar vertebra (L4) may result in a UMN bladder. The bladder will feel full and firm (though it may leak a little bit, i.e. urinary incontinence). Due to specific nerve impairment, the detrusor muscle cannot relax normally. The detrusor muscle wraps around the bladder and causes urine to be expelled when it contracts, wringing the bladder empty; when it is relaxed, it allows the bladder to fill with urine for storage. While the detrusor muscle is unable to relax, the external sphincter of the urethra is working hard — acting like a plug to keep the bladder from emptying. Though uncommon, the bladder can theoretically rupture if it is not emptied via manual expression (read more below). A bladder rupture is a surgical emergency!
  • Lower Motor Neuron (LMN) Bladder: LMN bladders may occur secondary to an IVDD lesion between the 4th lumbar vertebra and 3rd sacral vertebra (L4-S3). The detrusor muscle is somewhat impaired, but it is more relaxed than with a UMN bladder. However, the external sphincter of the urethra isn’t functioning as well. Therefore, the bladder will feel flaccid (floppy), and urine will constantly dribble. If affected pets are not promptly cleaned, urine scalding of the skin can occur.

Certain signs that your pet may have IVDD can differ depending upon which region of the spinal cord is being compressed.

• Trouble breathing: Typically, IVDD is not life-threatening, but in severe cases of disc compression between the 1st and 5th cervical (neck) vertebrae (C1-5), pets will experience respiratory failure. This is an EMERGENCY that can result in death due to respiratory arrest! Nerves that branch off this area of the spine innervate the lungs, and lack of proper “upstream” nerve impulses mean that the lungs fail to receive the necessary signals to function.
• Hanging the head down while standing and not wanting to move: This is a sign of cervical (or neck) pain.
• Horner’s Syndrome: Abnormal nerve supply to one side of the face, thus affecting the eye on that side of the face. This results in a constricted pupil (miosis), a droopy eyelid (ptosis), and a slightly sunken-in eyeball (enophthalmos). This may occur with IVDD occurring between the 6th cervical vertebra and 2nd thoracic vertebra (C6-T2).
• Schiff-Sherrington posture: The front legs are rigidly extended outwards from the body while the back legs remain floppy (or flaccid). This type of abnormal body posture may occur in some cases of IVDD occurring between the 3rd thoracic and 3rd lumbar vertebrae (T3-L3).
• “Double engine gate”: Quick, choppy steps in the front legs yet weakness and swaying in the back legs due to ataxia. This abnormal gait typically occurs with cases of IVDD between the 6th cervical and 2nd thoracic vertebrae (C6-T2).
• Root signature: Pain in one limb at rest (your pet may hold up the affected leg) that seems to subside when walking. If a forelimb is affected, the problem may be due to compression of nerve roots between the 6th cervical vertebra and 2nd thoracic vertebra (C6-T2). If a hind limb is the issue, nerve roots between the 4th lumbar and 3rd sacral vertebrae (L4-S3) may be affected. (Click here for more information about root signature on The Meowing Vet’s Instagram profile @themeowingvet.)

If you observe the aforementioned clinical signs in your dog or cat, it’s time to get to the vet’s office! Your pet will likely be in a great deal of pain and may bite (even if he or she doesn’t normally), so protect yourself by moving your pet cautiously. When transporting your pet, gently lift them into your vehicle (ideally into a crate or carrier for confinement) and help them out rather than trying to make them jump, which can worsen a spinal cord injury.

The emergence of these clinical signs also tend to follow a specific order in which they first appear: CP deficits develop first, followed by ambulatory (or gait) abnormalities, then motor function problems arise (weakness, or paresis, followed by paralysis), bladder problems arise next, followed by loss of superficial pain sensation, and finally loss of deep pain awareness. With treatment of the IVDD, these abnormalities (or myelopathy deficits) should improve in reverse order.

Potential Consequences of IVDD

Despite proper treatment of IVDD, some consequences of such an injury may develop or persist.

• Myelomalacia (or hematomyelia): This condition is a scary one! With spinal cord injury following intervertebral disc disease, hemorrhage and necrosis (or cell death) of the spinal cord can arise, oftentimes up to 5 days following the initial IVDD problem. This condition results in irreversible damage to and softening of the affected portion of the spinal cord. However, this type of bleeding and cell death may travel up the spinal cord, which can be deadly if it affects the nerves that branch off to control the lungs. A worsening of clinical signs despite prompt treatment may make your veterinarian suspicious of this problem. Obtaining a concrete diagnosis can be tricky and involves a combination of MRI and cerebrospinal fluid (CSF) analysis (or spinal tap).
• Frequent or persistent urinary tract infections (UTIs)
• The potential for a future IVDD issue (due to genetic predisposition or as a consequence of adjacent spinal insecurity caused by surgery)
• Osteoarthritis of the spine
• Long-lasting mobility issues (including paralysis) or lack of pain perception (sensory-negative)

 

How Is IVDD Diagnosed?

Intervertebral disc disease is diagnosed through a combination of a physical examination, a specialized neurological exam (or neuro exam), and imaging. A neuro exam will guide your primary veterinarian or veterinary neurologist in locating the approximate region of spinal injury. This is known as neurolocalization. Via a neuro exam alone, the location of the spinal cord problem may be determined to be between either the 1st and 5th cervical vertebrae in the neck (C1-C5), 6th cervical vertebra and 2nd thoracic (chest) vertebra (C6-T2), 3rd thoracic and 3rd lumbar (lower back) vertebrae (T3-L3), 4th and 6th lumbar vertebrae (L4-6), and 7th lumbar vertebra and 1st sacral (pelvic) vertebra (L7-S1). During a neurological examination, your vet will watch your pet’s gait and movement (if your pet is still mobile), check spinal reflexes, ensure that your pet has superficial and deep pain perception or a lack thereof (including sensation of the surrounding skin, known as the cutaneous trunci or panniculus response), and has bladder control. These tests will help your vet neurolocalize your pet’s problem (or spinal lesion). Your vet will also use their exam findings to assign your pet a Modified Frankel Score for assessing the extent of the spinal injury, which can also aid in determining prognostic outlook:

Modified Frankel Score
0	Normal clinical signs
1	Pain only
2	Conscious proprioception (CP) deficits, ataxia (uncoordinated movements), ambulatory paresis (can walk but weak)
3	Non-ambulatory paresis (cannot walk because so weak)
4	Non-ambulatory paralysis (cannot walk because cannot move)
5	Respiratory failure or urinary incontinence, no deep pain sensation

Imaging the spine helps neurolocalize the problem further, isolating it at a particular intervertebral disc (or discs) rather than a broader region of the spinal column. Imaging tools include spinal radiographs (or X-rays of the spine), MRI, and CT scan. Basic spinal radiographs may not always provide your vet with enough detail, so it may be paired with a myelogram, in which a special dye is injected into the spine; the dye permeates around the spinal cord to better highlight areas of injury. (Myelography is not without risk however. Injection is invasive and may result in bleeding, meningitis, or seizures. Your vet will determine the benefit vs. risk of this procedure for your specific pet.)

Why is knowing this detail so important? Because it will inform your pet’s neurology specialist where exactly to make his or her incision if your pet undergoes surgery to treat the IVDD. To gain even more insight, advanced imaging tests are recommended. These tools include either an MRI or CT scan (a.k.a. CAT scan), which are typically only available at specialty veterinary hospitals. (A CT scan may be performed with or without a myelogram.) Imaging also helps your vet differentiate IVDD from some of its lookalikes, including a fibrocartinagenous embolism (FCE), spinal fracture, spinal tumor, diskospondylitis, congential malformations, degenerative myelopathy, and meningitis. For similar differentiation purposes, your vet will likely wish to perform a cerebrospinal (CSF) fluid analysis (or spinal tap).

What Are the Treatment Options for IVDD?

Surgery is typically reserved for ‘back dogs” with uncontrollable pain, mobility problems, or loss of pain perception. In contrast, conservative (i.e. medical) therapy may be attempted depending on the circumstance, especially in less severe cases with a lower Modified Frankel Score (see chart above). For instance, patients that have cervical (neck) pain only with no other clinical signs (score of 1) tend to do well with medical management alone (though some may have relapses in pain later on). Financial constraints* and high anesthetic risk due to concurrent diseases are additional reasons why conservative therapy may be elected over surgery. (*Yes, back surgery is quite expensive. However, keep in mind that conservative management may be just as expensive or even more so over time due to more frequent veterinary visits due to flare-ups and rechecks.)

Conservative or Medical Management

Conservative treatment is a viable option for IVDD cases with a Modified Frankel Score of 1 (see chart above). It may also yield success in cases with a score of 2 or 3, but it should not be the choice for most cases of scores 4 or 5. Dogs with a score for 4 or 5 (who are losing both motor function and their ability to feel) should be referred for surgery in the majority of cases. Conservative management involves:

• Strict cage rest for 2-3 weeks to allow a tear in the annulus fibrosus to heal while also preventing additional nucleus pulposus material from herniating out.
• Pain control (analgesia): This is key as IVDD patients are painful! Such pain medication choices may include use of a non-steroidal anti-inflammatory drug (NSAID) or corticosteroid, opioid, anti-spasmotic agent to relax muscle spasms (such as methocarbamol or diazepam), and other drugs that alleviate neurogenic pain (like gabapentin or amantadine).
• Supplementary treatments to reduce inflammation and/or help manage pain.
  • “Cold” laser therapy: also stimulates blood supply to hasten healing as well as encourages the growth of new cells
  • Acupuncture
• Bladder management: In addition to learning how to manually express your pet’s bladder if he or she cannot empty it normally (read more below under “Post-Operative Care”), your vet may prescribe one of the following medications to make bladder emptying a bit easier. For UMN bladder: prazosin or phenoxybenzamine, diazepam or methocarbamol). For LMN bladder: bethanechol.

Depending on how your vet deems your pet’s progress upon rechecks (ideally in 2 days and then in 2 weeks following the initial IVDD event), a longer course of medical management may be recommended (often for 4 weeks total duration) or else your pet may be referred to surgery due to failure to improve.

Surgery

Surgery is strongly recommended for patients with a Modified Frankel Score (see chart above) of 3, 4, or 5 as these patients have severe weakness, cannot walk, and/or cannot perceive pain. Depending on the site of the IVDD, one of three surgical procedures may be advised: ventral slot (for C2-T1), hemilaminectomy (for T9-L6), and fenestration (a controversial technique for IVDD cases between either C2-5 or T10-L2). The common goal for each of these operations is to remove the diseased, compressing intervertebral disc material. The advantages of surgery over conservative management include a faster and more complete recovery with a reduced recurrence of future IVDD issues.

However, each surgery carries its own potential complications due to the delicate site being operated upon. Such complications include hemorrhage, infection, spinal instability (especially the vertebrae directly in front of and behind the operative site), laceration of the recurrent laryngeal nerve (in ventral slot operations; this results in laryngeal paralysis), and failure to completely de-compress the IVDD site. Therefore, such surgeries should be performed by a veterinary neurology specialist. Moreover, stem cell therapy in concert with surgery is of emerging interest in helping cases of deep pain-negative dogs (those dogs with IVDD who no longer have pain perception, i.e. are sensory-negative).

Post-Operative Care

Careful post-op care is imperative following an IVDD surgery. Follow your vet’s advice implicitly! Failure to adhere to your vet’s orders can result in dire complications. Pet owners must be dedicated to ensuring that they dogs or cats receive the following post-op care multiple times daily for several weeks. Such post-operative considerations include:

• As with conservative management, strict cage rest for 4 weeks is crucial to allow healing of the surgical site and to help manage pain. After 1 month of being confined to a small kennel, your dog or cat may gradually return to activity and gentle play.
• Pain control for 2 weeks (with medications discussed previously).
• Physical therapy / rehabilitation: Your vet may recommend that you work with a certified animal rehabilitator or physical therapist to expedite your pet’s recovery process. Even dogs with a very poor prognosis — those who are unlikely to ever walk again — may benefit from rehab, as there are some reports of “spinal walking” in which a new configuration of nerve connection following a severe spinal cord injury may allow such pets to regain some mobility.
• Passive range of motion (pROM): Your vet will show you a series of passive exercise to perform on each of your dog or cat’s limbs multiple times per day in order to prevent his or her joints from “locking up” before walking ability returns.
• Flip your pet every few hours in order to prevent bed sores (skin ulcers) caused by pressure points sustained from lying too long on one side.
• Help your pet get around safely with use of a sling or cart (a.k.a. doggie wheelchair). Getting up and moving around important for mental stimulation as well as muscle use.
• Manual bladder expression: Until your pet regains normal innervation of the bladder (if he or she ever does), you will have to help empty it several times daily via manual expression. Your veterinary team will guide you through this process in order to accomplish bladder emptying safely and effectively. Before you get the hang of it, bladder expression can be difficult, so your vet may prescribe one of the drugs listed above (under “Conservative or Medical Management”) to make the process a bit easier. However, even with regular manual expression by an experienced person, a small amount of urine is always retained in the bladder, so a UTI is nearly certain to emerge at some point.
• Prevention of further IVDD episodes (see the guidelines below)

Regular rechecks per your vet’s direction are also important to allow your vet to pick up on complications early on, to detect an emerging UTI, etc. Following surgery, your vet will likely wish for repeat radiographs (X-rays) to monitor healing of the surgical site.

What Is the Prognostic Outlook for IVDD?

Although IVDD is not typically a life-threatening problem in most scenarios, it may present serious consequences if not appropriately managed, causing significant impairment on the quality of life of a dog or cat.

The lives of patients with a Modified Frankel Score of 5 (sensory-negative, or unable to feel deep pain) are most significantly impacted. These patients suffer frequent UTIs, skin ulcerations, self-mutilation (they may chew on their bodies, often out of boredom since they can’t move around and explore their surroundings, yet they can’t feel the damage they’re doing). Therefore, immediate surgery is vital for these patients. Most of these sensory-negative dogs with IVDD in the thoracic/lumbar region that do go on to regain sensation post-op do so within 2 weeks of surgery (though it may take up to 3 months in some circumstances). Unfortunately, not all improve. Therefore, many pet owners may elect euthanasia to prevent undue suffering in the face of such a grave prognosis.

The sooner an animal is treated, the sooner it will likely recover. Below are the general “rules” that a dog or cat’s prognosis tends to follow, depending on the type and location of IVDD sustained.

• Cervical spine (neck region)
  • Hansen Type I Disc Degeneration
    • Conservative Management: Pain only = approximately 70% recovery. Pain with weakness and ataxia = good to fair prognosis. Non-ambulatory (cannot walk) = guarded to poor prognosis.
    • Surgery: Ambulatory (can walk) = 95% success rate. Non-ambulatory = approximately 75% success rate (better for spinal lesions higher up in the cervical spine than lower).
    • Sadly, many pets with IVDD between the 1st and 5th cervical vertebrae (C1-5) who are sensory-negative may succumb to respiratory failure, dying upon transport to the nearest veterinary emergency center.
  • Hansen Type II Disc Degeneration
    • Conservative Management: Pain only = often good prognosis. Pain with weakness and ataxia = good to fair prognosis. Non-ambulatory = poor prognosis.
    • Surgery: Ambulatory = 60-80% success. Non-ambulatory = approximately 60% success (though a longer recovery time). Cats are different, however, as surgery for this type of neck IVDD in felines carries a nearly 100% mortality rate.
• Thoracic or lumbar spine (chest or low back region, respectively)
  • Hansen Type I Disc Degeneration
    • General rule of thumb:
      

      Modified Frankel Score (or grade)	Conservative Management	Surgery
      1	95-100% recovery	97% recovery
      2	85-90% recovery	95% recovery
      3	80-85% recovery	95% recovery
      4	75-80% recovery	95% recovery
      5	50% recovery	50% recovery (if surgery within the first 48 hours)

      • Conservative Management: With each increase in the Modified Frankel Score, there is an approximate 15% decrease in the likelihood of recovery. (This drops to only a 50% chance of recovery once the ability to perceive sensation/pain is lost.)
      • Surgery: Over a 95% chance of recovery until loss of sensation, then only a 50% chance of recovery. If a non-ambulatory dog is to regain the ability to walk, most do so within 2 weeks following surgery.
  • Hansen Type II Disc Degeneration
    • Conservative Management: Unknown prognosis since this disease progresses so slowly and the main goal is the keep the pet comfortable.
    • Surgery: 60% success (though the primary goal is to prevent progression, not necessarily to fix previously acquired damage).

Prevention?: If My Pet Has Dealt with IVDD in the Past, What Things Can I Do to Reduce Chances of Re-occurrence?

Long-Term Guidelines Following an IVDD Event:

• Manage your pet’s weight! Obesity increases mechanical stress everywhere in the body, including the spine. A lean body weight removes some of this unnecessary stress.
• No jumping on or off the bed or couch! This means not leaving your pet up on a high surface unsupervised to avoid accidental falls or attempts to jump.
• No sudden, jerky exercise! This means no ball launchers, no fly ball, no long-range Frisbee-throwing, and no rough-housing!
• Be careful with stairs! When at all possible, carry your pet over up or down stairs, or install a ramp. You may also consider using a baby gate to block off access to steps and staircases.
• Swap out your dog’s neck lead for a chest harness. A leash attached to the neck may unintentionally place strain on the spinal column.
• Ask your vet if a supportive back brace may help add some protection to your individual pet’s spinal column.

– Maranda Elswick, DVM

 

If you suspect that your dog or cat may be suffering from Intervertebral Disc Disease (IVDD), schedule an appointment with your veterinarian. Some cases of IVDD are an EMERGENCY!

STAY IN THE LOOP OF The Meowing Vet’s DAILY ANIMAL VIDEOS AND SHARED NEWS ARTICLES BY FOLLOWING THE MEOWING VET ON FACEBOOK AND INSTAGRAM (@THEMEOWINGVET). AND SIGN UP FOR OUR BLOG MAILING LIST IN THE RIGHT-HAND SIDEBAR OF YOUR DESKTOP BROWSER SO YOU NEVER MISS OUT ON OUR WEEKLY INFORMATIVE ARTICLES. YOU CAN HELP US (AND ANIMALS) IMMENSELY BY SHARING OUR SITE’S ARTICLES WITH YOUR PET-LOVING FRIENDS AND INVITING THEM TO LIKE OUR FACEBOOK PAGE! BEFORE YOU GO, WE WANT TO SEE YOUR BEST PET PHOTOS TO FEATURE ON OUR WEBSITE; CLICK HERE FOR SUBMISSION GUIDELINES! AND WHILE YOU’RE AT IT, VISIT OUR PET SHOPPING PAGE!

---

Special thanks to Karen Dyer Inzana, DVM, PhD, DACVIM (Neurology); Theresa Pancotto, DVM, MS, MS, DACVIM (Neurology); and Samantha Emch, DVM, MS, DACVIM (Neurology) for superb clinical teaching.