Managing Disorders of the Canine Spine

Introduction

Dog being examined

Spinal pain is a common complaint in canine patients, but many spinal disorders share similar clinical symptoms and history 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 Whenever significant spine-related pain is present in a canine patient, it is important to consider:[2]

• Severe cervical pain is one of the few conditions that can cause a dog to “scream or cry” in pain
• Dogs with spinal pain may exhibit a number of postural abnormalities such as hunched back and torticollis
• Nerve root sign indicates nerve root irritation leading to unilateral limpness of the extremity
• Compression or degeneration of the spine may cause paralysis/paralysis of the limbs with ataxia. However, it is important to note that these changes can also be due to lesions other than the spine, such as brain tumors and midthoracic lesions
• Dogs with acute and/or progressive underlying spinal pain must always be referred to a veterinarian as an urgent matter

Atlantoaxial Instability

Jump accidents can cause AA instability

Atlantoaxial (AA) instability occurs after atlantoaxial joint subluxation or dislocation. This can be congenital (usually due to abnormal formation of ligaments in the animal’s vertebrae) or occur after an accident. [2][3] This is especially true for injured small dogs Jump from tall buildings. [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 dogs or small breeds. [4][5] Therefore, it should be suspected in any small dog showing signs of C1 to C5 myelopathy. [2] The diagnosis of AA instability can usually be made on survey radiographs. [5]

[6][7]

Treatment

Treatment can 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

Conservative management is indicated when:[2]

• An acute history of neurological signs
• Surgery may not provide sufficient stability for immature bones
• Financial considerations

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

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

The use of cervical manipulation has been found to be an appropriate treatment option for young dogs experiencing acute onset of unstable AA with clinical signs regardless of the severity of arthritis at presentation.

Surgical

The goal of surgical management of AA instability is to reduce subluxation. It is recommended for patients with arthritis or neck pain that does not respond to conservative treatment.[5]

Both back and forth approaches have been described. The prognosis for postoperative patients is generally good.[5]

Physiotherapy Management

As both conservative and surgical patients are likely to be in splint initially the treatment strategies will be similar. Patients are rarely referred to physical therapy during the first stage of recovery (i.e. after being splinted).

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

• Static proprioceptive and balance training
  • Rhythmic stabs
  • 3-legged stand / diagonal stand (patients must be supported to avoid falling) .
  • Abnormalities such as walking backwards (depending on patient compliance) .
• Functional mobility exercises, such as sit-stand/handstand (depending on patient compliance)
• Once the patient is out of the splint, rehabilitation can begin to gradually restore cervical range of motion (ROM) and cervical strength and proprioception
• It is important to ensure that the dog has good stability and motion control on the chest harness

Caudal Cervical Spondylomyelopathy

Young great dane, higher risk of CCSM

Caudal cervical myelopathy (CCSM), also known as Wobblers syndrome and cervical instability, is a progressive degenerative disorder of the disc ligaments and cervical facet joints, culminating in spinal cord and nerve root compression. [9]

It can affect any breed, but young Great Danes and older Dobermans are more susceptible. [10] Disc-associated CCSM is common in Doberman Pinschers and other large breeds. [9]

Pathological abnormalities associated with CCSM can be roughly divided into two groups according to the age of the animal at presentation:[2]

1. Puppies (such as Great Danes under two years of age) often have spinal deformities and secondary soft tissue changes that result in spinal cord compression
2. Middle-aged dogs (usually large and giant dogs) with spinal cord compression due to dorsal annulus hypertrophy or Hansen type 2 disc rupture

Most dogs with CCSM will have a history of slowly progressive symptom onset that gradually worsens over time. However, it is important to note that acute exacerbations are possible. CCSM most commonly occurs at C5/6 and/or C6/7. [2]

Key Features

The main features of CCSM include “waggle” gait paralysis and cervical spine pain:[11][2]

• Symptoms range from mild ataxia of the hind legs to ambulatory quadriplegia
• Owners will report the dog has a waddling gait on the hind legs and “hyperarticulation” of the hind feet
• Affected dogs typically have a bowed head and neck posture and resist extension of the cervical spine
• Neck pain is usually absent, but a few dogs experience mild neck pain during neck manipulation
• Dogs with CCSM tend to walk with stiff, stilted front legs
• Often there are hind leg defects – these are made worse by neck extension
• Except in more severely affected dogs, neurologic abnormalities in the front legs will be absent or less severe than in the hind legs
• Definite diagnosis can only be made by myelography

[12]

Treatment

Conservative Management

Conservative management is only favored when there are financial constraints or the animal has comorbidities that preclude surgery. [2] De Decker and colleagues found that conservative management of CCSM was associated with a “prudent prognosis.” [13]

Treatment usually consists of:[9]

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

Surgical Management

Surgical techniques include:[2]

• Dorsal laminectomy
• Ventral cervical decompression
• Improved distraction stabilization technology

Postoperative care depends on the animal’s neurological state, but dogs will require a harness rather than a collar for the rest of their life. [2]

Physiotherapy Management

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

Treatment will focus on:[2]

• Managing pain
• Enhance cervical spine strength proprioception/sensory motor function
• Active ROM (avoiding hyperextension)
• Static strengthening of the neck muscles – this can start in the first post-op week
• If the dog has the ability to retrieve the object – progressive loading of the neck extensors in the moderate range can be achieved by allowing the dog to retrieve the object

Sensorimotor rehabilitation may include:[2]

• Eye Movements – Initially neutral neck position, then move to progressive lateral flexion
• Foraging activities
• Dog touching a target with its nose

Degenerative Myelopathy

DM, common in German Shepherds

Degenerative myelopathy (DM) is an insidious, progressive neurodegenerative disorder of the spinal cord. It begins in late adulthood and has been compared to amyotrophic lateral sclerosis in humans. It’s common in German Shepherds, but can occur in any breed. [14] Neurologic symptoms usually begin Develops in dogs 5 years or older. The average age of onset in large dogs is 9 years. DM causes generalized proprioceptive ataxia and spastic paralysis of the upper motor neurons (UMNs) of the pelvic extremities. Eventually it can lead to paraplegia. [15]

The earliest clinical signs of DM are:[15]

• Pelvic limb ataxia and mild spastic paralysis
• Frayed nails and asymmetrical limping of pelvic limbs
• Spinal reflexes consistent with UMN palsy (usually limited to T3 to L3 or L3-S3) [16]

As the duration of the disease increases dogs will develop lower motor neuron (LMN) paralysis in the pelvic limbs and eventually the thoracic limbs will be affected. LMN symptoms appear including hyporeflexia of the patellar and withdrawal reflexes flaccid paralysis and muscle stretch paralysis. Most are large dogs develop non-ambulatory paraparesis (i.e. inability to bear weight) within 6 to 9 months of developing clinical symptoms of DM.[15]

Diagnosis

Because DM presents similarly to other acquired spinal diseases, it can be difficult to diagnose. Additionally older dogs often have various orthopedic and musculoskeletal co-mordities that can further complicate the diagnosis.[15]

Diseases that may similarly coexist with DM include:[15]

• Degenerative lumbosacral syndrome
• Intervertebral disc disease
• Spinal cord neoplasia
• Degenerative joint diseases (eg, hip dysplasia or cranial cruciate ligament rupture) .

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

[18][19]

Treatment

Overall, the long-term prognosis for DM is poor.[20] There are no evidence-based treatment options for DM. While DM is believed to be an autoimmune disease, vaccines appear to have no long-term benefit.[15]

It has been suggested that a treatment including exercise vitamins aminocaproic acid and N-acetylcysteine may be helpful.

Physiotherapy Management

Dog wheelchair, available commercially.

Exercise therapy focusing on muscle strength resistance exercises and movement-related activities is considered an important part of supportive and symptomatic DM treatment.[2] However DM disease will progress regardless of physical therapy treatment. So the purpose of physical therapy is to delay deconditioning and remain active as long as possible.[2] A study by Kathmann et al found that dogs receiving intense exercise lived longer (255 days) than dogs receiving moderate exercise (130 days) or no exercise (50 days).[16]

The exercise programs used in Kathmann’s study were: active exercises passive exercises with therapeutic fluid injections and hip protection.[16] However, the authors did not describe how their protocol was developed and there is little consensus in the literature about practical strategies don’t DM. To review this protocol see page 2 of the course.

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

General recommendations

• Cardiorespiratory exercise training
• Alternate exercise and rest periods to avoid excessive fatigue
• Water gymnastics – allows greater mobility and strength
• Strength training
• Flexibility exercise

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

Spondylosis

Old large dogs most affected by Spondylosis

Spondylosis is defined as ankylosis of a joint of the spine[21] (i.e. bony formation around the spine). It is a non-inflammatory condition that commonly occurs in the caudal thoracic and cranial lumbar spine in canine patients. Older, larger dogs have size risk of developing this condition.[2][21] This condition is generally not considered to be of great clinical importance[22] except in working dogs where decreased spinal flexibility may restrict function. However in severe cases osteophyte formations may extend dorsolaterally compressing the spinal portion of the intervertebral foraminae of the nerve roots.[2]

Diffuse Idiopathic Skeletal Hyperostosis (DISH) is a subtype of skeletal hypertosis. DISH is a systemic disorder affecting the axial and peripheral skeleton.[21]

• It is more prevalence in ageing dogs
• It causes ossification of soft tissues including the ventral longitudinal ligament of the spine [2][23]
• 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 osteophytes at the epiphyseal margin, not extending beyond the endplates
• Grade 2: Enthesophyte that extends beyond the endplates but does not connect to adjacent vertebrae
• Grade 3: Attachments on adjacent vertebrae connect to each other, forming a radiographic bony bridge between the two

Key Features

Patients are usually asymptomatic until an acute event causes the flare, such as a bone spur or a fracture of a bridge. [2]

If present, clinical signs may include:[2][22]

• Stiffness
• Limited spinal and hindlimb motion and associated gait changes
• Pain

Note: Spondylosis can coexist with other spinal disorders such as osteoarthritis, disc disease, and DISH. [2]

Treatment

Patients with significant spinal pain and stiffness tend to be managed conservatively with NSAIDs or analgesics, and lose weight as needed. Patients with neurological deficits or severe/persistent spinal pain require further diagnostic testing such as CT MRI and analysis Cerebrospinal fluid to narrow down the cause of its symptoms. [2]

Physiotherapy Management

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

Physiotherapy aims to:[2]

• Manage pain if present
• Optimizing spinal mobility – “normal” spinal mobility may not be realistic due to bony bridges
• Appropriate enhancements to improve functionality
• Optimizing general and spinal proprioception
• Modify activities as needed (to maintain function and slow down dysregulation)
• Educate clients on the likelihood and associated signs of osteophyte fractures

Depending on where and how advanced the skeletal changes are, dogs with spondylosis are often able to live full lives. Activity tolerance varies widely between patients and may change as the pathology progresses. Encouraging optimal liquidity is important, but respect pain. [2]

Because of the diffuse nonspecific nature of spondylosis, exercise selection is guided by the patient. For example, some dogs may respond well to hydrotherapy, while others may have flare-ups. Progression should be made according to the comfort of the patient. Customers should also be educated About the possibility of symptom flare-ups, why they occur and how to manage them. Once symptomatic onset occurs, these patients tend to become chronic pain patients with focal pain features [2].

Maintaining physical strength and mobility should become part of the patient’s life for a long time. It is important to work with the patient to find practical ways to implement a consistent and consistent appropriate program in the home or office.[2]