Intervertebral

Intervertebral Disk Disease in Canines: 

Intervertebral Disk Disease in Canines Anna Larson December 11, 2004 AnSc 3221 – Principles of Animal Breeding

Topics to be Covered: 

Topics to be Covered I. What is IVDD? II. Types of IVDD III. Locations and Signs IV. Genetics V. Breeds VI. Diagnosis VII. Treatment options VIII. Decreasing its occurrence in canines

What is IVDD?: 

What is IVDD? Intervertebral disk disease occurs when the disk material between the vertebrae ruptures, forcing its interior fluid out towards the spinal column. This puts the spinal column under a great deal of pressure, causing pain and possibly paralysis.

Two Types of Intervertebral Disk Disease: 

Two Types of Intervertebral Disk Disease 1. Type I IVDD - complete rupture of disk - primarily occurs in dogs bred that have short, thick legs - occurs at a young age (3-6 years) - commonly occurs in several sites - relatively quick developing with serious consequences 2. Type II IVDD - protrusion of disk material without complete rupturing - typically occurs in large breed dogs - seen in older dogs (8-10 years) - usually occurs in only one disk - clinical signs develop slowly

There are two general places where IVDD occurs:: 

There are two general places where IVDD occurs: 1. Cervical (neck) 2. Thoracolumbar (mid-back) IVDD is rarely seen in the thoracic region because extra ligaments connect the ribs and help to reinforce the outer, fibrous portion of the disk.

Where does cervical IVDD occur?: 

Where does cervical IVDD occur? There can be an instability between C-1 and C-2. This can cause neurological problems, especially in large dogs.

Signs of Cervical IVDD: 

Signs of Cervical IVDD Dog may appear quiet and lethargic Sensitive to touching in the neck area or obvious neck pain Shivering Crying when moving head Decreased appetite Dragging of rear legs or paralysis of all four limbs (tetraparesis)

Where does thoracolumbar IVDD occur?: 

Where does thoracolumbar IVDD occur? This occurs towards the end of the thoracic vertebrae at the thoracolumbar (T-L) junction. This is the second area in which it is very common area to have disk disease.

Signs of Thoracolumbar IVDD: 

Signs of Thoracolumbar IVDD Quiet and lethargic Sensitive upon touching back area where ribs end Shivering Crying Dragging of rear legs Inability to move Decreased appetite Hunched back Uncontrollable bladder and bowel movements No feeling, or paralysis in rear end

Other Characteristics and Signs of IVDD: 

Other Characteristics and Signs of IVDD One side of the body may be affected more than the other due to the disk material bulging on one side more than the other. Muscle spasms around the affected area of the spinal cord may also occur.

Genetics of IVDD: 

Genetics of IVDD Polygenic Heritability has been estimated to be approximately 0.7 in dachshunds. Presence of disk calcifications at an early age may indicate the likelihood of future development of IVDD.

Canine Breeds Predisposed to IVDD:: 

Canine Breeds Predisposed to IVDD: Bassett hound Dachshund Welsh corgi Pomeranian Shih tzu Mini poodle Doberman pinscher Beagle French bulldog Pekinese Lhasa apso Cocker spaniel

Diagnostic Tests: 

Diagnostic Tests Myelogram Spinal Tap Radiographs CT scan MRI

Diagnosis: Myelography: 

Diagnosis: Myelography An x-ray of the spinal cord is taken after injection of air or a radio-opaque substance into the affected area. Necessary as a means of distinguishing disk protrusion from other diseases such as spinal neoplasia and degenerative myelopathy Most important in determining the site(s) of disk herniation as well as in lateralization of the disk material within the spinal canal prior to surgical decompression

Diagnosis: Radiography: 

Diagnosis: Radiography Used mainly to rule out other disorders, not as the sole diagnostic tool for IVDD Does not allow for visualization of the spinal cord or nerve roots as myelography does Radiograph above: There is calcified disk material in the spinal canal between L-2 and L-3, and it is painful and weak in its rear legs. Myelogram below: outlines spinal cord in the lumbar vertebrae. The vertical column of dye at the top is where the needle was inserted to inject the dye.

Diagnosis: MRI: 

Diagnosis: MRI Magnetic Resonance Imaging Used if myelogram is inconclusive Provides information about the health of the spinal cord

Treatment Options: 

Treatment Options Medication and strict cage rest Surgery Acupuncture Therapeutic ultrasound Neuromuscular stimulation Massage Passive range of motion Hydro-treadmill Ambulation exercises

Treatment: Medication and Cage Rest: 

Treatment: Medication and Cage Rest Anti-inflammatory drugs will help alleviate pain by reducing the swelling around the spinal cord. Along with cage rest, medications will allow the disk time to repair with no additional fluid leakage. Dog should be let out only when necessary and should be on a short leash at all times. Consider surgery if there is not improvement within three weeks.

Treatment: Surgery: 

Treatment: Surgery Recommended if dog is showing signs of neurological damage or with repeated episodes of pain and weakness. Surgical procedures are the only way to remove disk material that is compressing the spinal cord. Prognosis typically ranges from fair to good. Poor prognosis with paralysis or if there was a loss of pain perception for more than 24 hours.

Treatment: Physical Therapy: 

Treatment: Physical Therapy Acupuncture is used to increase the rate of nerve regeneration and to relieve pain. Ultrasound can be helpful in decreasing inflammation, pain and muscle spasms. Neuromuscular stimulation can help to slow down or prevent muscle atrophy. Gentle massage is used to stimulate circulation. Range of motion can be used to prevent joint degeneration. Hydro-treadmill and ambulation exercises help to strengthen and re-educate the activities of muscles and nerves.

How can we decrease the occurrence of intervertebral disk disease in canines?: 

How can we decrease the occurrence of intervertebral disk disease in canines? Develop a DNA bank to help make progress in mapping the genes predisposing particular dogs to IVDD. Compile genealogical information and pedigrees to make a more accurate assessment of the heritability of the disease. Use radiographs to screen dogs for calcifications at an early age and again before breeding. Do not use dogs with any signs or history of IVDD for breeding.

Resources: 

Resources http://www.tops-vet-rehab.com/injuries.html#IVDD http://www.thedachshundnetwork.com/discdisease.htm http://www.nationaldog.com.au/2002_july/Dachs_Test_for_Back.pdf http://www.upei.ca/~cidd/Diseases/musculoskeletal/intervertebraldiskdisease.htm http://www.upei.ca/~cidd/intro.htm http://www.lbah.com/Canine/ivd.htm http://www.upei.ca/~cidd/intro.htm http://www.upei.ca/~cidd/intro.htm http://www.nationaldog.com.au/2002_july/Dachs_Test_for_Back.pdf http://www.vgl.ucdavis.edu/research/canine/projects/ivdd/ Saunders, Textbook of Veterinary Internal Medicine., copyright 2000.