Managing Disorders of the Canine Spine

Introduction[edit | edit source]

Dog being examined

Spinal pain is a common presenting complaint in canine patients, but many disorders of the spine have similar clinical signs and histories and must be considered in the differential diagnosis.[1] This page discusses some of the more common causes of spinal dysfunction in dogs. The following points are important to consider whenever a canine patient presents with apparent spine-related pain:[2]

  • Severe cervical pain is one of the few conditions that will cause “screaming or crying” pain in the dog
  • Dogs with spinal pain may display numerous postural abnormalities such as a hunched back, low carriage of the head and torticollis
  • Nerve root signs indicate that there is irritation of the nerve root, resulting in unilateral limb lameness
  • Spinal compression or degeneration may cause limb paresis / paralysis with associated ataxia. However, it is important to note that these changes can also be due to pathologies outside of the spine, such as brain tumours and mid-thoracic pathology
  • Dogs with acute and / or progressive potential spinal pain must always be referred to the veterinarian as a matter of urgency

Atlantoaxial Instability[edit | edit source]

Jumping accident, may cause AA instability

Atlantoaxial (AA) instability occurs after the subluxation or dislocation of the atlantoaxial joint. This can be congenital (often due to the abnormal formation of ligaments in the animal’s vertebrae) or occur after an accident.[2][3] This is especially true for smaller dogs who get injured jumping from tall structures.[2]

AA instability can cause:[2]

  • Spinal cord compression
  • Pain and disability

It can occur in dogs and cats, but in canine patients, it is common in young, toy- or small-breed dogs.[4][5] It should, therefore, be suspected in any small dog who presents with signs of a C1 to C5 myelopathy.[2] Diagnosis of AA instability can typically be made on survey radiographs.[5]

Treatment[edit | edit source]

Treatment may be conservative or surgical. It is important to note that manual manipulation of the neck should be avoided if AA instability is suspected.[2]

Conservative[edit | edit source]

Conservative management is indicated in the following instances:[2]

  • An acute history of neurological signs
  • Immature bones for which surgery may not provide adequate stabilisation
  • Financial considerations

The goal of conservative management is to encourage fibrous tissue that can stabilise the AA joint to form, and to prevent further subluxation. Treatments include:[2]

  • Cervical splints
  • Pain management
  • Strict exercise restriction for around 8 weeks

It has been found that the use of a cervical splint is a viable treatment option for young dogs who experience an acute-onset of AA instability with clinical signs, regardless of the severity of the neurological deficits on presentation.[8]

Surgical[edit | edit source]

The goal of surgical management of AA instability is to achieve reduction of the subluxation. It is recommended for patients who have neurological deficits or neck pain that is not responding to conservative management.[5]

Both dorsal and ventral approaches have been described. The prognosis for patients following surgery is usually good.[5]

Physiotherapy Management[edit | edit source]

As both conservatively and surgically managed patients are likely to be in a splint initially, the treatment approaches will be similar. Patients are not often referred for physiotherapy in the initial stages of recovery (i.e. the splinted stage).

Owners should be advised to perform exercises that focus on maintaining strength and function in the rest of the body. Exercises may include:[2]

  • Static proprioceptive and balance training
    • Rhythmic stabs
    • 3-legged stand / diagonal stand (patients should be supported to prevent them falling)
    • Non-habitual movements such as walking backwards (depending on patient compliance)
  • Functional mobility exercises such as sit-stand / down-stand (depending on patient compliance)
  • Once the patient is out of its splint, progressive restoration of cervical active range of motion (ROM), as well as rehabilitation of the strength and proprioception of cervical spine can commence
  • It is important to ensure that the dog has good stability and motor control of the thoracic sling

Caudal Cervical Spondylomyelopathy[edit | edit source]

Young great dane, higher risk of CCSM

Caudal cervical spondylomyelopathy (CCSM), also known as Wobblers syndrome and cervical vertebra instability, is a degenerative, progressive disorder of the intervertebral disc, ligaments, and facet joints of the cervical spine that, ultimately, results in compression of the spinal cord and nerve roots.[9]

It can affect any dog breed, but younger Great Danes and older Dobermanns are more likely to be affected.[10] Disc‐associated CCSM is often found in Doberman pinschers and other large‐breed dogs.[9]

The pathological abnormalities associated with CCSM can be roughly divided into two groups based on the age of the animal at presentation:[2]

  1. Young dogs (e.g. Great Danes less than two years of age) generally have vertebral malformation with secondary soft tissue changes that cause spinal cord compression
  2. Middle-aged dogs (typically large- and giant-breeds) have spinal cord compression as a result of hypertrophy of the dorsal annulus fibrosis or Hansen type 2 disc rupture

Most dogs with CCSM will be presented with a history of a slow, progressive onset of symptoms that gradually worsen with time. It is, however, important to note that acute exacerbations are possible. CCSM most commonly occurs at C5/6 and/or C6/7.[2]

Key Features[edit | edit source]

Key characteristics of CCSM include a “wobbling” gait, paresis and cervical pain:[11][2]

  • Symptoms range from mild ataxia of the rear legs to non-ambulatory tetraparesis
  • The owner will report the dog has a wobbly, unsteady gait in the hind legs, and “knuckling over” on the hind feet
  • Affected dogs will generally have a low head and neck posture and resist extension of the cervical spine
  • Cervical pain is not typically present, but a small number of dogs will have mild cervical pain on neck manipulation
  • Dogs with CCSM tend to walk with a stiff, stilted gait in the front legs
  • Deficits of the hind legs are typically present - these are made worse with neck extension
  • Neurological abnormalities in the front legs will be absent or less severe than in the hind legs apart from in dogs who are more severely affected
  • Definitive diagnosis can only be made with myelography

[12]

Treatment[edit | edit source]

Conservative Management[edit | edit source]

Conservative management tends to be indicated only when there are financial constraints, or the animal has comorbidities that would prevent surgery.[2] De Decker and colleagues found that conservative management of CCSM is associated with a “guarded prognosis”.[13]

Treatment usually consists of:[9]

  • Restricted activity
  • Using a body harness
  • Analgesia and / or steroids

Surgical Management[edit | edit source]

Surgical techniques include:[2]

  • Dorsal laminectomy
  • Ventral cervical decompression
  • Modified distraction-stabilisation technique

Post-operative care depends on the animal’s neurological status, but a dog will require a harness instead of a collar for the rest of its life.[2]

Physiotherapy Management[edit | edit source]

In the case of surgery, activity limitations will be determined by the surgeon. It will be important to maintain and improve the dog’s general strength, mobility and exercise tolerance. Progressions will depend on the patient’s tolerance and the surgeon’s guidelines.

Treatment will focus on:[2]

  • Managing pain
  • Enhancing cervical strength, proprioception / sensorimotor function
  • Active ROM (avoiding hyperextension)
  • Static strengthening of cervical muscles - this can start during the first week post-surgery
  • If the dog has retrieving skills - progressive loading of the cervical extensors in mid-range can be achieved by getting the dog to retrieve articles

Sensorimotor rehabilitation may include:[2]

  • Eye movements - initially with neck in neutral before moving to progressive lateral flexion
  • Foraging activities
  • Dog touching a target with its nose

Degenerative Myelopathy[edit | edit source]

DM, common in German Shepherds

Degenerative myelopathy (DM) is an insidious, progressive neurodegenerative condition of the spinal cord. It begins in late adulthood and has been compared to amyotrophic lateral sclerosis in humans. It is common in German Shepherds, but can occur in any breed.[14] Neurological signs usually start to develop in dogs aged 5 years or older. The average age of onset in large-breed dogs is 9 years. DM causes general proprioceptive ataxia and upper motor neuron (UMN) spastic paresis of the pelvic limbs. Ultimately, it leads to paraplegia.[15]

The earliest clinical signs of DM are:[15]

  • Ataxia and mild spastic paresis in the pelvic limbs
  • Worn nails and asymmetric pelvic limb lameness
  • Spinal reflex abnormalities that are consistent with UMN paresis (often localised to T3 to L3 or L3-S3)[16]

As disease duration increases, dogs will develop lower motor neuron (LMN) paralysis in the pelvic limbs and eventually the thoracic limbs will also be affected. LMN signs emerge, including hyporeflexia of the patellar and withdrawal reflexes, flaccid paralysis, and widespread muscle atrophy. Most large dogs develop non-ambulatory paraparesis (i.e are unable to support their weight) within 6 to 9 months of developing clinical signs of DM.[15]

Diagnosis[edit | edit source]

Because DM presents similarly to other acquired spinal cord diseases, diagnosis can be difficult. Moreover, older dogs often have various orthopaedic and neurological co-mordities, which can make diagnosis more challenging.[15]

Disorders that may present similarly and coexist with DM include:[15]

A diagnosis of DM can only be during a postmortem examination,[17] so DM is usually given as a “presumptive diagnosis” based on clinical signs and when other pathologies have been excluded.[15]

Treatment[edit | edit source]

Overall, the long term prognosis of DM is poor.[20] There is a lack of evidence-based medicine approaches to the management of DM. While it is believed that DM is an immune-mediated neurodegenerative disease, immunosuppressive therapies do not appear to have any long-term benefits.[15]

It has been proposed that a management approach including exercise, vitamin support, aminocaproic acid, and N-acetylcysteine may be beneficial.[2]

Physiotherapy Management[edit | edit source]

Dog wheelchair, available commercially.

Exercise therapy, focusing on muscle power, exercise tolerance and mobility-related activities, is considered to be an important part of the supportive and symptomatic treatment of DM.[2] However, the disease process of DM will continue regardless of physiotherapy treatment. Thus, the goal of physiotherapy is to delay deconditioning and maintain function for as long as possible.[2] One study by Kathmann and colleagues found that dogs who receive intensive physiotherapy have longer survival times (255 days) than dogs who receive moderate (130 days) or no physiotherapy (50 days).[16]

The exercise programme used in the Kathmann study consisted of: active exercise, passive exercise, massage, hydrotherapy and paw protection.[16] However, the authors did not describe how they developed their protocol and there is little consensus in the literature about which modalities are of benefit for DM. To view this protocol see page 2 of the study.

Follow this link to learn about Training a Dog to Use a Wheelchair

General recommendations[edit | edit source]
  • Cardiorespiratory exercise training
  • Alternating bouts of exercise with rest periods to avoid excessive fatigue
  • Aquatic exercise  - allows for greater mobility and strength gains
  • Strength training
  • Flexibility exercise

It is important to remember that interventions should be designed around the patient's unique presentation and environmental challenges, and it should focus on function.[2]

Spondylosis[edit | edit source]

Old large dogs more affected by Spondylosis

Spondylosis is defined as "ankylosis of a vertebral joint"[21] (i.e. the production of bone spurs along the spinal vertebrae). It is a degenerative, noninflammatory condition that occurs most often in the caudal thoracic and cranial lumbar spine in canine patients. Older, large-breed dogs are at greater risk of developing this condition.[2][21] In most cases, this condition is not considered to be of great clinical relevance,[22] except in working dogs where reduced spinal flexibility might limit activity. However, in severe cases, osteophyte formations may extend dorsolaterally, compressing spinal nerve roots at the level of the intervertebral foraminae.[2]

Diffuse Idiopathic Skeletal Hyperostosis (DISH) is a variant of spondylosis. DISH is a systemic disease that affects the axial and peripheral skeleton.[21]

  • It is more prevalence in ageing dogs
  • It results in ossification of soft tissues, including the spinal ventral longitudinal ligament[2][23]
  • It is often misdiagnosed as severe spondylosis
  • Diagnosis is made on x-ray, CT and MRI[22]

Grading of spondylosis:[2]

  • Grade 0: No enthesophytes
  • Grade 1: Small enthesophyte at the edge of the epiphysis that does not extend past the end plate
  • Grade 2: Enthesophyte extends beyond the end plate, but does not connect to enthesophyte on the adjacent vertebra
  • Grade 3: Enthesophytes on adjacent vertebrae connect to each other forming a radiographic bony bridge between the two

Key Features[edit | edit source]

Patients are often asymptomatic until an acute incident causes a flare, such as a fracture of a bony spur or bridge.[2]

Clinical signs, if present, may include:[2][22]

  • Stiffness
  • Restricted spinal and hind limb motion and associated changes in gait
  • Pain

NB: Spondylosis can co-exist with other spinal conditions such as osteoarthritis, intervertebral disc disease and DISH.[2]

Treatment[edit | edit source]

Patients with apparent spinal pain and stiffness tend to be managed conservatively with nonsteroidal anti-inflammatory drugs or analgesics and weight loss as needed. Patients with neurologic deficits or severe / persistent spinal pain require further diagnostic testing such as CT, MRI, and analysis of cerebrospinal fluid in order to narrow down the cause of their symptoms.[2]

Physiotherapy Management[edit | edit source]

There are no evidence-based clinical guidelines available and treatment is determined based on the dog's assessed deficits. Spondylosis is commonly associated with secondary areas of joint degeneration, and these dysfunctions must also be identified and addressed.[2]

Physiotherapy aims to:[2]

  • Manage pain if present
  • Optimise spinal mobility - “normal” spinal mobility may not be realistic due to bony bridging
  • Strengthen where appropriate to improve function
  • Optimise general and spinal proprioception
  • Modify activities as necessary (to preserve function and to slow deconditioning)
  • Educate clients about the possibility of osteophyte fracture and associated signs

Dogs with spondylosis are usually able to live full, active lives, depending on the location of bony changes and the degree of progression. Activity tolerance will vary widely between patients and may change as the pathology progresses. It is important to encourage optimal mobility, but to respect pain.[2]

Because of the diffuse, non-specific nature of spondylosis, exercise selection is guided by the patient. For instance, some dogs may respond well to hydrotherapy while others may experience flare ups. Progressions should be made according to the patient’s comfort. Clients should also be educated on the potential for symptom flare-ups, why these occur and how to manage them. These patients can often become chronic pain patients with features of centralised pain once there have been symptomatic episodes.[2]

Exercises to maintain strength and mobility should become part of the patient’s lifestyle in the long-term. It is important to work with the client to find practical ways of implementing a suitable, regular and sustainable programme at home or at the practice.[2]

References[edit | edit source]

  1. Cardy TJ, De Decker S, Kenny PJ, Volk HA. Clinical reasoning in canine spinal disease: what combination of clinical information is useful? Vet Rec. 2015;177(7):171.
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 2.26 2.27 2.28 2.29 2.30 2.31 2.32 2.33 Van der Walt A. Managing Disorders of the Canine Spine Course. Plus , 2021.
  3. Takahashi F, Hakozaki T, Kouno S, Suzuki S, Sato A, Kanno N et al. Atlantooccipital overlapping and its effect on outcomes after ventral fixation in dogs with atlantoaxial instability. The Journal of veterinary medical science. 2018;80(3):526–31.
  4. Planchamp B, Bluteau J, Stoffel MH, Precht C, Schmidli F, Forterre F. Morphometric and functional study of the canine atlantoaxial joint. Research in Veterinary Science. 2020;128:76-85.
  5. 5.0 5.1 5.2 5.3 Slanina MC. Atlantoaxial Instability. Vet Clin North Am Small Anim Pract. 2016;46(2):265-75.
  6. Southeast Veterinary Neurology. What is Atlantoaxial Instability in Dogs? || Southeast Veterinary Neurology. Available from: https://www.youtube.com/watch?v=q2Q9d_jHznY [last accessed 1/3/21]
  7. MercolaHealthyPets. Dr. Becker Discusses Atlantoaxial Instability in Dogs. Available from: https://www.youtube.com/watch?v=mpaIZdJWBgg [last accessed 1/3/21]
  8. Havig ME, Cornell KK, Hawthorne JC, McDonnell JJ, Selcer BA. Evaluation of nonsurgical treatment of atlantoaxial subluxation in dogs: 19 cases (1992-2001). J Am Vet Med Assoc. 2005;227(2):257-62.
  9. 9.0 9.1 9.2 Reints Bok TE, Willemsen K, van Rijen MHP, Grinwis GCM, Tryfonidou MA, Meij BP. Instrumented cervical fusion in nine dogs with caudal cervical spondylomyelopathy. Vet Surg. 2019;48(7):1287-98.
  10. Plessas J. Treating neck pain in dogs – neurological five-step approach [Internet]. Vet Times. 2016 [cited 1 March 2021]. Available from: https://www.vettimes.co.uk/app/uploads/wp-post-to-pdf-enhanced-cache/1/treating-neck-pain-in-dogs-neurological-five-step-approach.pdf
  11. Shekhar P, Singh GD, Kumar S, Singh AK, Choudhury S, Shukla A. Wobbler's syndrome in labrador and rotweiller pups: an emerging concern in canines: a review. International Journal of Science, Environment and Technology. 2018;7(1):361-4.
  12. MercolaHealthyPets. Wobbler's Syndrome in Dogs. Available from: https://www.youtube.com/watch?v=teYOyBn9xCY [last accessed 1/3/2021]
  13. De Decker S, Bhatti SF, Duchateau L, Martlé VA, Van Soens I, Van Meervenne SA, Saunders JH, Van Ham LM. Clinical evaluation of 51 dogs treated conservatively for disc-associated wobbler syndrome. J Small Anim Pract. 2009;50(3):136-42.
  14. Holder AL, Price JA, Adams JP, Volk HA, Catchpole B. A retrospective study of the prevalence of the canine degenerative myelopathy associated superoxide dismutase 1 mutation (SOD1:c.118G > A) in a referral population of German Shepherd dogs from the UK. Canine Genet Epidemiol. 2014;1:10.
  15. 15.0 15.1 15.2 15.3 15.4 15.5 15.6 Coates JR, Wininger FA. Canine degenerative myelopathy. Vet Clin North Am Small Anim Pract. 2010;40(5):929-50.
  16. 16.0 16.1 16.2 Kathmann I, Cizinauskas S, Doherr MG, Steffen F, Jaggy A. Daily controlled physiotherapy increases survival time in dogs with suspected degenerative myelopathy. J Vet Intern Med. 2006;20(4):927-32.
  17. Nardone R, Höller Y, Taylor AC, Lochner P, Tezzon F, Golaszewski S. Canine degenerative myelopathy: a model of human amyotrophic lateral sclerosis. Zoology. 2016;119(1):64-73.
  18. Heron Lakes Animal Hospital. Degenerative Myelopathy in Dogs. Available from: https://www.youtube.com/watch?v=VTKrZnN1XPs [last accessed 4/3/2021]
  19. AKC Canine Health Foundation. How to Care for a Dog with Degenerative Myelopathy. Available from: https://www.youtube.com/watch?v=ezYqUJTbAL0 [last accessed 4/3/2021]
  20. Neeves J, Granger N. An update on degenerative myelopathy in dogs. Companion Animal (2053-0889) [Internet]. 2015 Jul [cited 4 March 2021];20(7):408–12.
  21. 21.0 21.1 21.2 Widmer WR, Thrall DE. Canine and feline vertebrae. In: Thrall DE. Veterinary diagnostic radiology. 7th Edition. St Louis: Elsevier, 2018. p249-70.
  22. 22.0 22.1 22.2 Meij BP. Spondylosis and spinal abnormalities: when are they relevant? [Internet]. 2012 [cited 5 March 2021]. Available from: https://www.vin.com/apputil/content/defaultadv1.aspx?id=5328287&pid=11349
  23. Kranenburg HC, Westerveld LA, Verlaan JJ, et al. The dog as an animal model for DISH?. Eur Spine J. 2010;19(8):1325-1329.