Smal animal SC disease

Question 1

Typical age and breeds for FCEM?

Answer 1

most common in young adult dogs of the larger breeds of dogs:
miniature schnauzer, Labrador retriever,
boxer breeds

Dog: 2 months to 13 years and 5 months, with a median of 4–6 years in the majority of studies

Cats: DSH
from 6 months to 17 years (median, 10 years)

Question 2

Why are some animals very painful at the onset of FCEM?

Answer 2

Central neurogenic pain refers to spontaneous pain associated with CNS parenchymal lesions that do not involve the meninges. Acute spinal cord injury or ischemia may be related to spontaneous pain in addition to some loss of sensory function caudal to the lesion. The extreme discomfort exhibited by some dogs at the onset of spinal cord ischemia associated with fibrocartilaginous embolism may well be an example of spontaneous central neurogenic pain. The pathophysiology of this form of pain is poorly understood, but disinhibition of dorsal gray column neuronal cell bodies that project into the spinothalamic pathway or a disturbance of the lateral spinothalamic tract, the ventral spinothalamic tract, or both, which results in spontaneous discharge, are possible explanations.

Question 3

4 hypothesis of embolus entering the vasculature in FCEM

Answer 3

1) Direct penetration of nucleus pulposus fragments into spinal cord or vertebral vessels
2) Chronic inflammatory neovascularization (arterial and venous) of the degenerated
intervertebral disc
3) Presence of embryonic remnant vessels within the nucleus pulposus (which is normally
avascular in adults)
4) Mechanical herniation of nucleus pulposus into the vertebral bone marrow sinusoidal venous channels, with subsequent retrograde entrance into the basivertebral vein
and internal vertebral venous plexus.

Question 4

What is a Schmorl node?

Answer 4

intervertebral disc material in the marrow of the vertebral bodies (one of proposed mechanisms for FCEM, common in humans, rare finding in dogs)

Question 5

Where does nephroblastoma usually occur in the dog, and what is the typical signalment?

Answer 5

T 10-L 2 SCS
Intradural-extraparenchimal

Dogs younger than 2,5 years old

Question 6

Why does a nephroblastoma usually always involve SCS T10-L2)

Answer 6

correlates with the site of embryonic renal development from intermediate mesoderm and the embryonic mesonephros.

Question 7

Most common cause of infectious myelitis in dogs?

Answer 7

Canine distemper virus. Other infectious diseases are caused by protozoal agents (Toxoplasma gondii, Neospora caninum), Rickettsia species, and fungal agents.

Question 8

Most common isolates from dogs with discospondylitis?

Answer 8

Staphylococcus pseudintermedius is the most common isolate. Streptococcus species and Escherichia coli have also been isolated in this lesion. Be aware that, particularly in intact male and female dogs, Brucella canis has been identified in these infections and that it is contagious to humans.
Aspergillus spp.- German Shepherd Dogs

Question 9

MST for dogs with nephroblastoma?

Answer 9

70 days (one study) - 374 (another)

BrewerD.M,Cerda-GonzalezS,DeweyC.W,et al.Spinal cord nephroblastoma in dogs: 11 cases (1985-2007).J Am Vet Med Assoc.2011;238:618–624.

Question 10

Where do 80% of IVD extrusion occur in the dog? Why?

Answer 10

T10 and L3 vertebrae

This may relate to the increased motion of the vertebral column at this level compared with the more stable thoracic area. In addition, between the first 10 thoracic vertebrae, an intercapital ligament courses transversely across the dorsal surface of the intervertebral disc to connect the heads of the ribs where they articulate with both adjacent vertebrae. This is an added support to the articulation of the vertebral bodies and may help to prevent intervertebral disc herniation or protrusion between thoracic vertebrae cranial to T10.

Question 11

In which domestic species is lymhoma the most common vertebral neoplasia?

Answer 11

Cats and cattle

Question 12

Most common region for lymphoma in the spinal cord?

Answer 12

Thoracolumbar, usually restricted to 1-3 foramina

Question 13

Typical dog breeds for deg. Myelopathy?

Answer 13

German shepherd dog
boxer,
Cavalier King Charles spaniel,
Pembroke Welsh corgi,
kuvasz,
Bernese mountain dog.

Question 14

4 stages of DM based on clinical signs?

Answer 14

1. Ambulatory pelvic limb UMN paresis and GP ataxia
2. Nonambulatory paraparesis and GP ataxia to paraplegia with areflexia in the pelvic limbs, mild muscle atrophy, and some incontinence
3. LMN paraplegia with thoracic limb paresis and ataxia
4. LMN tetraplegia, severe atrophy, dysphagia, and tongue paresis

Question 15

Typical breeds and signs of SAD

Answer 15

Pug dogs and french bulldogs

GP ataxia and UMN paresis, affected dogs often have fecal incontinence and have a low tail carriage

Question 16

Wat is shown in the image? Multiple Afghan hounds from the litter are recumbant, with a spastic paraparesis and GP ataxia of the pelvic limbs. They are 8 MO

Answer 16

A microscopic section of the C8 spinal cord segment from a young Afghan hound with myelinolysis. Note the sparing of the fasciculus proprius and the nerve roots.

Afghan hound myelinolytic encephalomyelopathy is inherited as an autosomal recessive gene disorder. It is a unique primary demyelination that causes necrosis of myelin but spares the axons. It appears to start in the myelin in the midthoracic spinal cord segments and to progress cranially and caudally. The clinical signs begin with mild pelvic limb spastic paresis and ataxia and loss of control of the trunk muscles by 7 to 10 days. They are followed by thoracic limb spastic paresis and ataxia and then recumbency by about 14 to 21 days. The initial onset of clinical signs ranges between 3 and 13 months of age. The myelinolytic lesion is bilaterally symmetric in all the funiculi but spares the fasciculus proprius. The “naked” demyelinated axons float unsupported in their funiculi among a plethora of lipid-filled macrophages. One of the earliest publications on this disorder erroneously explained this lesion as a vascular compromise. Primary demyelination with axonal sparing cannot be caused by any known vascular disorder. The unique distribution of this lesion is unexplained. Most of these dogs also have the same primary demyelination of the axons that surround the dorsal nucleus of the trapezoid body. No clinical signs have been associated with the lesion in the trapezoid body. This inherited myelinolytic disorder was confirmed at autopsy in the dogs in this litter. MRI studies of these dogs have not been described.

Question 17

Which vertebral body has a high chance of fracture and why?

Answer 17

Cranial aspect of the body of C2 (axis)

This may be the result of the physical stress that is placed there, where the dens articulates with the atlas. The latter acts as a fulcrum when flexion of the head and neck is forced. In addition, the presence of two growth plates in the cranial portion of the body of the axis may be a risk factor for a fracture there.

Question 18

Name the ossification centres of the axis

Answer 18

• Center 1 - cranial articular surface of the axis body and the dens.
• Intercentrum 1 - for the ventral arch (body) of the atlas.
• Centrum of proatlas: small apex of the dens.
• Intercentrum 2: narrow ossification center between the ossification centers of centrum 1 and centrum 2.
• Centrum 2: central region of the body of the axis.

Question 19

Which ligaments participate in the normal alignment between atlas and axis?

Answer 19

1) transverse ligament of the atlas - attached on both sides of the ventral arch of the atlas and passes dorsal to the dens
2) dorsal longitudinal atlantoaxial ligament - dorsal arch of the atlas and the spine of the axis
3) apical and two lateral (alar) ligaments - attach the apex of the dens to the basioccipital bone cranially

Question 20

Where are the pathological lesions with “inherited encephalomyelopathy and polineuropathy” of rotweilers located?

Answer 20

The spinal cord lesion consists of a bilateral symmetric axonopathy with secondary demyelination and astrogliosis, which is most pronounced in the lateral and ventral funiculi. This lesion is not limited to the spinocerebellar tracts. Many tracts are affected, including the UMN tracts, which is why the gait disorder is typical for a dysfunction of the GP and UMN systems. The thoracolumbar segments are most affected, which possibly suggests where the degenerative lesion first develops and explains why the clinical signs are first observed in the pelvic limbs. Vacuolation of neuronal cell bodies is scattered through the spinal cord and brain, with no other evidence of any microscopic abnormality of these neurons. The brains of these dogs test negative for prion protein. A neuropathy is prominent in the recurrent laryngeal nerves and scattered in other long nerves. Denervation atrophy of all the intrinsic laryngeal muscles except for the cricothyroideus is significant

Question 21

Neuro signs in “inherited encephalomyelopathy and polineuropathy” of rotweilers

Answer 21

The clinical signs begin at about 6 to 8 weeks of age and may start with either inspiratory dyspnea or paraparesis and pelvic limb ataxia. Some of the dogs that first exhibited the signs of laryngeal paralysis had laryngeal tie-back surgery to improve their breathing before the clinical signs were first observed in the pelvic limbs. It is paramount that the veterinary surgeon be aware of this disorder and counsels the owner appropriately before surgery. All dogs progress in a few weeks to tetraparesis and ataxia in all four limbs. Some dogs develop megaesophagus and regurgitate, and some dogs have bilateral microphthalmia. These small eyes appear to be sunken into the orbits, and therefore the third eyelids become prominent. Horner syndrome does not occur in these dogs. A few dogs have been reported to exhibit clinical signs of dysfunction of the cerebellum or the vestibular system

Question 22

Name the inherited neurodegenerative disorders of the Rottweiler breed

Answer 22

1) inherited encephalomyelopathy and polineuropathy
2) neuroaxonal dystrophy
3) leukoencephalomyelopathy
4) motor neuron disease
5) polyneuropathy (axonopathy)
6) distal neuropathy
7) dystrophynopathy (Duchane type of muscular dystrrophy)

Question 23

Which nerves innervate the lateral scapular muscles (eg. Atrophy of lateral scapular muscles seehn in dogs with disk associated spondlomyelopatyhy

Answer 23

C6-7 SCS - suprascapular nerve (supraspinatus and infraspinatus m.) and subscapular nerve (subscapular muscle)

Question 24

Which storage disease is most common in West highland white terriers and Cairn terriers?

Answer 24

Globoid cell leukodystrophy (Krabbes disease)

Question 25

Which enzyme is deficient in Globoid cell leukodystrophy?

Answer 25

Galactosylceraminase-1 (Beta galactocerebrosidase)

Accumulation of galactosylsphingosine (psychosine)

Question 26

What is the most likey DD? (See image)

2 month old Cairn terrier with signs of a progressive gait disorder that initially affected the pelvic limbs and progressed to tetraparesis with sublte cerebellar signs

Answer 26

Globoid cell leukodystrophy (Krabbes disease)

Galactosylceramidase 1 deficiency (accumulation of galactosylsphingosine)