THE LOW DOWN ON IVDD
Understanding intervertebral disc disease
Your questions answered
IT’S DIFFICULT TO ASCERTAIN IF YOUR DOG WILL BE EFFECTED BY THIS GENETIC DISEASE; TYPICALLY SIGNS APPEAR WHEN THE DOG IS BETWEEN 3 and 8 YEARS OLD. HOWEVER, THEY ARE NOT EVER IMMUNE NO MATTER WHAT AGE.
When it comes to IVDD, education is key!
Remember prevention is better than cure
A diagram showing a dachshund’s spine and all the vertebrae in each section of the spine.
T4-13, L1-8, S1-3, and Ca1 vertebrae.
Image credit: The Dachshund Spine by Lisa J Emerson
Getting down to the nitty gritty of IVDD
How is IVDD categorised?
Disc Disease IVDD was first categorised by Hansen in 1952. It was categorised into Type 1 and Type 2. There are two ways a disc can degenerate and Hansen Type 1 is the most commonly type seen in dachshunds. It is also seen in other breeds, but is seen most commonly in the chondrotropic breed of dogs. It is more correctly known as hypochondroplastic.
What does hypochondroplastic mean?
It is a gene mutation which causes abnormal cartilage production. But this is what also contributes to the characteristic body shape of these breeds, like dachshunds (i.e. short legged bendy legged dogs). As well as dachshunds, other breeds can also be affected; to name a few Pekinese, Bassets, Beagles, Corgis and some Spaniel breeds. As a result, these are the types of dogs we see having problems. The cartilage in the dachshund breed isn’t made properly; hence there is not the long bone growth seen in long legged bred dogs.
So, what happens?
Due to this gene mutation, (hypochondroplasia), the nucleus (gel like soft centre) becomes hard and rigid, which becomes cartilaginous. Hansen Type 1, or (Chondroid Metaplasia), which is the fancy name given to Hansen Type 1 disease, results in changes to the nucleus pulposus. This is where the nucleus (jelly like soft centre pulp) degenerates. The matrix of the nucleus loses the ability to hold water, and therefore the loss of fluid results in replacement of cartilage and becomes calcified. When calcification occurs, the nucleus can no longer act as a cushion and the compressive forces are transferred to the annulus (the outer shell). With increased forces, the annulus becomes thicker, in an attempt to stabilise the spine. Through its loss of biomechanical integrity, the nucleus then explodes through the annulus. This applies direct pressure to the spinal cord, which in turn, causes concussive damage as well as persistent compression. When this happens, we see the signs and symptoms that our dachshunds display so suddenly.