Snow Leopard

Snow Leopard
Snow Leopard cub (7 mos old) - Cape May County Zoo

Tuesday, August 9, 2011

DOWNward Dog

This is a cute dog doing a yoga pose referred to as the downward dog - appropriate, I know. 

Today's blog is NOT about this. It's about a condition called intervertebral disk disease (IVDD) - specifically affecting the thoracolumbar spine.  The American College of Veterinary Surgeons has a more detailed web page on IVDD. 

This condition can affect the cervical spine as well but I'll leave that for another day.  

These dogs present with everything from subtle signs of pain  and lethargy to weakness in one or both hind legs to being completely paralyzed in the hind end. 

The most common breeds we see this in are the dogs with the "long" backs - dachshunds are at the top of the list (they have 10 times the risk of ALL other breeds combined!) but we also see it in corgis, beagles, shih tzus and Lhasa apsos. It CAN occur in any breed however. It VERY rarely occurs in cats. Obesity (which is a common problem in the dachshunds as well as many breeds) does add to the likelihood this will happen.

The disk between the vertebrae herniates and compresses the spinal cord, resulting in an increasing loss of neurologic function until it basically dies and is beyond saving. 

It can happen either traumatically (more common in the younger dogs) - they are hit by a car, another dog, jumping off the couch, they jumped over your deck onto the lawn, etc OR it can occur by the simple act of curling up to sleep (more common in the older dogs). As the dog ages, the disk material becomes more brittle and it takes much less to cause this material to "explode" into the space.

A complete and thorough neurologic exam helps determine whether this can be medically managed or needs immediate surgical intervention. We assess conscious proprioception (curling the dog's toes under - normally should be corrected by the dog within milliseconds!), superficial pain (pinching the skin), motor ability, reflexes and finally deep pain. If deep pain is lost the prognosis is poor even with surgery.

Interestingly, x-rays of the spine do not always show anything. In some cases we can see a narrowing of the space between the vertebrae.

In MOST cases, these dogs can be managed with cage rest, steroids and sometimes muscle relaxers and/or other pain meds (ie  Tramadol). However, it is important to note if the dog is getting worse (has increasing loss of function in the hind legs, worsening pain or difficulty with urination/defecation) because that could signal the need for surgical intervention. This downward spiral can happen quickly - even within hours. DO NOT wait! Call your vet! 

These dogs are then sent to a board-certified veterinary surgeon who will likely first want to do an MRI to get a definite diagnosis (there can be a few other things that cause similar signs - including tumors, a condition called fibrocartilaginous embolism, infections, etc) AND to get the exact location of the lesion/s. Surgery involves decompressing the spinal cord by removing the disk fragments causing the problem. 

This is NOT an inexpensive endeavor, however and if you go this route be prepared to spend $5000 or more when all is said and done (diagnostics, surgery, meds, post op care). These dogs can do great and return to completely normal function. This depends heavily on how severe the neurologic loss is at the time of presentation.

I saw a 2 yr old chihuahua last week that went to another vet approximately 2 weeks prior and was diagnosed with IVDD.  He was put on appropriate medications. The owner believed his condition was due to Lyme disease (she didn't understand the information given to her but it seemed to be due in large part to a language and education barrier). When I saw the dog, he had gotten significantly worse (confirmed after I reviewed his previous records) to the point that, now, we have to recommend euthanasia. 

A few weeks prior to that I saw an 11 yr old Pomeranian who had gone out back for a few minutes and when the owners went to check on him, he seemed paralyzed in the hind end. They didn't know what happened at all. They were not near a road, cars, etc. There were no other pets in the area. This dog had some deep pain function and because they couldn't go to the specialist, we went with trying medications. However, the next day the dog was still very painful and was not urinating on his own. I finally convinced them to go to the specialist because he was definitely declining neurologically. Unfortunately, they were unable to have the surgery due to financial constraints.

Dogs can live with hind end paralysis. They make carts for these dogs that can be fitted specifically to YOUR dog. Google  "carts for dogs"  and you will see several companies that do this. The key thing to note is that these dogs often need to have their bladders manually expressed daily AND are more prone to urinary tract infections. I have met a few that have done well with VERY dedicated and attentive owners who know when they need to be seen by a veterinarian.   

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