Bilateral Hind Limb Conditions

Question 1

Cause: Degenerative myelopathy

Answer 1

Degeneration of axons and mylein sheaths in thoracolumber spinal cord

Question 2

Degenerative myelopathy Predisposed breeds

Answer 2

Older (>8yr) Large and giant breed dogs

GSDs especially

Question 3

Signs: Degenerative myelopathy

Answer 3

Gradual loss of voluntary motor functions and position sense (knuckling/dragging feet, crossing legs when turning, dysmetria, ataxia), muscle atrophy, asymmetical parsesis

UMN signs in hind limbs (LMN if nerve roots effect later on)

No spinal hyperesthesia or pain, sensation normal

Urinary and fecal continence spared until late in progression

Forelimbs affected late in disease progression.

Question 4

Dx: Degenerative myelopathy

Answer 4

Definitive dx: histopathy- axonal and myelin degeneration with atrogliosis

Clinical dx: appropriate signs and exclusion of other causes, elevation of myelin based protein in CSF from lumbar cistern

Genetic test: SOD1 gene esp small breeds

Question 5

Tx: Degenerative myelopathy

Answer 5

None

Phyiotherapy and good nursing may improve life expectancy

Corticosteroids, NSAIDS, B-vit have no effect

Question 6

Cause: Lumbosacral instability

Answer 6

L7-S1: Hansen type II degeneration, compression of cauda equina, proliferation of interarcuate ligament

Question 7

Signs: Lumbosacral instability

Answer 7

Early: Lumbosacral pain, difficulty rising/negotiating stairs

Advanced: Rear limb paresis, decreased extension of hock, pseudohyperreflexia of pateller reflex (loss of sciatic nerve), flexor withdrawl decreased except hip, urinary and fecal incontinence, tail may be immobile

Pain on deep palpation- tail jack test more specific than lordosis test (lordosis will elicit paint with coxofemoral pathology too)

Question 8

Signalment: Lumbosacral instability

Answer 8

Older (5-8) large breed dogs esp working breeds

Transitional vertebra predisposes (8x more likely)

Rarely cats

Question 9

Dx: Lumbosacral instability

Answer 9

Myelography (extended and flexed views), epidurography, MRI, CT to confirm nerve compression

CSF not helpful

Question 10

Tx: Lumbosacral instability

Answer 10

Cage rest, NSAIDS/gabapentin/muscle relaxers/tramadol/prednisone- signs will recur with exercise

Surgical: lumbosacral dorsal laminectomy and removal of ligaments/bone that are putting pressure on the nerves- will not improve continence

Surgival: dorsolateral foramenotomy- less instability at L7/S1

Question 11

Ddx: Lumbosacral instability

Answer 11

Diskospondylitis, neoplasia, lumbosacral ostyeochrondrosis, degenerative myelopathy, cruciate4 rupture, prostate disease, trauma, coxofemoral arthritis

Question 12

Hansen type II: Thoracolumbar intervertebral disk disease

Answer 12

Replacement of nucleus pulposus with fibrocartilage by 7-8yr

Slow protrusion causing nerve/spinal compression pain by stretching of dorsal longitudinal ligament

Chronic, but may be more serious due to prolonged nerve damage

Question 13

Hansen type I: Thoracolumbarr intervertebral disk disease

Answer 13

Replacement of nucleus pulposus with hyaline cartilage (4-18mo) that often becomes calcified. Chondrodystrophic breeds especially

Explosive protrusion of nucleus pulposus material into spinal cord

Acute, but may be less serious if treated right away

Question 14

Cats: Thoracolumbarr intervertebral disk disease

Answer 14

Calcification is common, often in upper cervical and midlumbar region

Usually subclinical, may result in pain and difficulty walking

Question 15

Hx: Thoracolumbarr intervertebral disk disease

Answer 15

May be acute, subacute, or chronic

CS vary from hyperesthesia with no deficits to paralysis and anesthesia

Question 16

Signs: Thoracolumbarr intervertebral disk disease

Answer 16

UMN signs in hind limbs- most occur in T11-L2

Loss of

1. Conscious proprioception
2. Voluntary motor function, control of urination/defecation
3. Superficial pain
4. Deep pain- poor prognosis

Question 17

Dx: Thoracolumbarr intervertebral disk disease

Answer 17

Spinal radiography- collapse of disc spaces, calcified disc material in vertebral canal

Myelography- definitely locate lesion

CT/MRI

Question 18

Grade 1: Thoracolumbarr intervertebral disk disease

Answer 18

Spinal hyperesthesia without neurological deficits

Question 19

Grade 2: Thoracolumbarr intervertebral disk disease

Answer 19

Paresis but ambulatory

Question 20

Grade 3: Thoracolumbarr intervertebral disk disease

Answer 20

Paresis, non-ambulatory

Question 21

Grade 4: Thoracolumbarr intervertebral disk disease

Answer 21

Paralysis with deep pain

Question 22

Grade 5: Thoracolumbarr intervertebral disk disease

Answer 22

Paralysis without deep pain

Question 23

Tx: Grade 1, 2, and 3 Thoracolumbar intervertebral disk disease

Answer 23

Strict cage rest for ~2wks and 2 weeks after resolution of clinical signs, prednisone for pain

1/3 will have recurrence, chronic steroids may worsen prognosis

If no improvement consider surgery

Never give NSAIDS for pain- gastric ulceration

Question 24

Tx: Grade 4 Thoracolumbar intervertebral disk disease

Answer 24

May show improvement with cage rest but will relapse- pain control and bladder management (UTI common w/UMN bladder); some dogs may deteriorate with cage rest

Surgical best option: over 90% recovery, operate within 24hrs if possible; Dorsal hemilaminectomy and disc fenestration of surrounding discs

Question 25

Tx: Grade 5 Thoracolumbar intervertebral disk disease

Answer 25

Typically will not recover regardless of treatment Surgical approach: dorsal hemilaminectomy and durotomony for more accurate prognosis; If deep pain has not returned 2wks post-op it is unlikely to recover Successful sx: motor/bladder function returns after ~4wks and will continue to improve, physiotherapy crucial for recovery

Question 26

Grade 4 and 5Thoracolumbarr intervertebral disk disease Physiotherapy

Answer 26

1. flexion and extension of the limbs 2. massaging the limbs 3. assisted walking and standing

Question 27

Prevention: Thoracolumbarr intervertebral disk disease

Answer 27

No known behavioral risk factor | Percutaneous disc ablation to destroy T10-L4 and prevent extrusions

Question 28

Cause: Diskospondylitis

Answer 28

Infection of the cartilaginous endplates with involvement of the intervertebral disc Vertebral osteomyelitis- S. intermedius, Brucella canis, Streptococcus spp.

Question 29

Signalment: Diskospondylitis

Answer 29

Large, middle-aged dogs | Rare in cats

Question 30

Signs: Diskospondylitis

Answer 30

Common in C6/7, T4-6, and L7/S1 Hyperesthesia, pyrexia, depression, weight loss Untreated: Proliferation of fibrous connective tissue and new bone leading to spinal cord compression Complications: Spinal cord myelitis, pathological vertebral fractures, disc protrusion, vertebral instability

Question 31

Dx: Diskospondylitis

Answer 31

Spinal cord signs with concurrent systemic signs of infection, CSF often normal or with mildly elevated proteins Definitive diagnosis: spinal radiographs (bone lysis, sclereosis, spondylosis), scintigraphy or MRI

Question 32

Tx: Diskospondylitis

Answer 32

Minimal neurological involvement: analgesic and parenteral abx Neurological dysfunction: surgical decompression/stabilization Prognosis good unless fungal infection

Question 33

Types/Locations of Vertebral/spinal neoplasia

Answer 33

1. Intramedullary- astrocytoma, oligodendroglioma, ependymoma 2. Metastatic intramedullary- hemangiosarcoma, melanoma, carcinomas 3. Intradural-extramedullary- meningioma, nephroblastoma, MPNSTs 4. Extradural- vertebral osteosarcoma, chondrosarcoma, multiple myeloma, hemangiosaroma, fibrosarcoma and mets

Question 34

Most common type of Vertebral/spinal neoplasia in Dogs

Answer 34

Spinal cord Meningioma, 2nd Hemangiosarcoma

Question 35

Vertebral/spinal neoplasia are usually found in what portion of the spinal column

Answer 35

Thoracolumbar area

Question 36

Signalment: Vertebral/spinal neoplasia

Answer 36

Medium to large breed dogs around 6yr (30%

Question 37

Most common type of Vertebral/spinal neoplasia in Cats

Answer 37

Extradural lymphosarcoma in the thoracolumbar spinal chord esp cats with FeLV Cerebral meningiomas

Question 38

Signs: Vertebral/spinal neoplasia

Answer 38

Root signs with progressive neurological deficits (depends on nerves effected)

Question 39

Diagnosis: Vertebral/spinal neoplasia

Answer 39

Lytic lesions on radiographs, abnormalities in the dye column on myelogram Intramedullary- thin and divergent columns of dye Intradural-extramedullary- characteristic "golf-tee" sign Extradural- deviation of dye towards the lumen

Question 40

Tx: Vertebral/spinal neoplasia

Answer 40

Meningiomas- resection No tx- survival limited to weeks/months Tx: post-op radiation/chemotherapy can increased life expectancy

Question 41

Cause: Vertebral fractures and luxations

Answer 41

Trauma to sacroiliac and thoracolumbar areas especially Tail tugs resulting a sacrococcygeal luxations/fractures common in cats

Question 42

Signs: Vertebral fractures and luxations

Answer 42

History of trauma and evidence of other wounds Spinal hyperesthesia or anesthesia, decreased/absent voluntary motor activity, misalignment of spine, crepitus, Schiff-Sherrington LMN signs caudal to lesion if spinal edema that may resolve to UMN signs after 24hrs

Question 43

Diagnosis: Vertebral fractures and luxations

Answer 43

Radiography CT/MRI more precise

Question 44

Tx: Vertebral fractures and luxations

Answer 44

Analgesia as needed, correct other life threatening traumas (shock, hypovolemia, etc), steroids (limited efficacy), 20% Mannitol to reduce spinal edema once hypovolemia is corrected Surgical decompression of spinal cord if unstable lesion Stabilization works better for smaller patients; larger patients may benefit more from cage rest

Question 45

Bulldogs and boston terriers

Answer 45

Hemivertebrae- failure of left and right centers of ossification to fuse

Question 46

Block or fused vertebrae

Answer 46

Incomplete segmentation of two or more vertebrae May not cause neurological signs

Question 47

Spinal dysraphism

Answer 47

Bulldogs and bostons- spina bifida, meningiocele, myelomeningocele Manx cats- sacrococcygeal dys/agenesis Weimeraners- inherited myelodisplasia

Question 48

Spinal synovial cysts

Answer 48

Articulation facets, may cause pain Tx: surgical decompression and stabilization

Question 49

Spondylosis deformans

Answer 49

Common in older dogs, rarely clinical Formation of bone spurs/ridges at intervertebral spaces

Question 50

Old dog hind limb tremors

Answer 50

Old terriers and large breeds predisposed Mild tremors in hind limbs while standing or at rest that often disappear with movement; may be slowly progressive Unknown etiology and no tx

Question 51

Dancing dobermans

Answer 51

Flexion of pelvic limbs while standing may be slowly progressive over years (CP deficits) No discomfort, walking unaffected