Intervertebral Disc Disease (IVDD)

Summary

Intervertebral disc disease (commonly referred to by veterinarians with the acronym "IVDD") is a common disease of the joints of the spine. It occurs when one or more of the discs that serve as cushions between the vertebrae of the spine degenerates. With this degeneration comes a hardening and eventual herniation of the nucleus pulposus contained within the disc. Because the spinal cord is immediately adjacent, compression of this extremely sensitive structure is the consequence of herniation.

IVDD is a disease of highly variable severity due to the wide degree to which the cord may be compressed. Minimal compression may lead to mild, temporary pain while severe compression can cause permanent paralysis. Thoracolumbar (lower back area) and cervical (neck region) spinal compressions are most common.

Two types of IVDD have been described. Type I occurs in chondrodystrophic (dwarfed) breeds of dogs whose normal cartilage development has been tinkered with genetically for the purposes of a short, stout appearance. In these cases the degeneration of the disc material occurs essentially as a result of a cartilage deformity, it happens at a relatively young age (3 to 6 is most typical), and it tends to recur episodically in multiple areas along the spine.

Type II is much less common. It happens with fibrous degeneration of the disc material later in life. Older large breed dogs are most often affected by this typically less severe version of disc disease. Only one area of the spine tends to become diseased with this type of IVDD.

Affected Breeds

The more typical, Type I IVDD is common in the Dachshund along with many other chondrodystrophic breeds of dogs including:

• Basset Hound

• Beagle

• French Bulldog

• Lhasa Apso

• Pekingese

• Pomeranian

• Shih Tzu

• Welsh Corgi

• Cocker Spaniels

• Cavalier King Charles Spaniels

Doberman Pinschers are the only non-chondrodystrophic large breed dog to be predisposed to this disease. It's referred to as "Wobbler's disease" in this breed. Apart from affecting larger breed dogs more commonly, Type II IVDD seems to offer no specific breed predispositions.

Treatment

IVDD is considered a highly treatable disease.

Rest and anti-inflammatory drugs tend to help those whose intervertebral disc disease symptoms have not yet progressed to severe chronic pain or catastrophic neurological dysfunction. A full thirty days of strict rest is generally recommended following each individual episode of disc-related symptoms to prevent further disc displacement (which could cause compression of the spinal cord or exacerbation of any existing compression).

Severely affected patients almost always require surgery but the call can be a tough one to make in cases where pain is the only sign. Duration and severity of pain are helpful in determining whether surgery is the right choice in cases where the threat of outright paralysis isn't an immediate issue.

The exact type of procedure employed differs according to the spinal segments affected. For example, a procedure called a dorsal hemilaminectomy is used to gain access to most of the spinal canal, remove prolapsed disc material and relieve compression on the spinal cord whereas a so-called "ventral slot" version of the same is the approach taken when prolapsed disc material affects the spinal cord underlying the neck vertebrae.

A board-certified veterinary surgeon or veterinary neurologist is always tapped for these delicate surgical procedures.

Veterinary Cost

The cost in cases progressing to severe neurological dysfunction or unmanageable pain can be very steep once advanced imaging studies are deemed necessary. $1,000 to $3,000 is a typical cost for the sophisticated imaging techniques required in these cases. Surgery is definitely a high-cost proposition in these cases. Individual surgical procedures themselves will typically cost anywhere from $1,500 to $4,000.

Prevention

Ideally, all affected animals should be removed from the breeding pool. Unfortunately, IVDD's unknown mode of inheritance means that it's difficult to convince breeders to carefully evaluate their breeding stock for the possible elimination of this disease. Reducing the breeding of chondrodystrophic dogs would almost certainly reduce the incidence of IVDD but that seems a highly unlikely approach given the increasing popularity of these breeds.

References

LeCouteur RA, Child G. 1995. Diseases of the spinal cord. In EJ Ettinger and EC Feldman (eds.) Textbook of Veterinary Internal Medicine, pp. 629-696. WB Saunders Co., Toronto.

Bennett D, May C. 1995. Joint diseases of dogs and cats. In EJ Ettinger and EC Feldman (eds) Textbook of Veterinary Internal Medicine, p. 2032-2077. WB Saunders Co., Toronto.

Stigen O, Christensen K. 1996. Calcification of intervertebral discs in the dachshund: an estimation of heritability. ACTA Veterinaria Scandinavica 34(3): 357-361.