Methocarbamol for dogs with IVDD (intervertebral disk disease) is a commonly prescribed medication that helps provide relief to dogs suffering from this painful condition. In order to better understand how this medication works and its exact mode of action, it helps to gain a better insight on what happens when dogs are suffering from intervertebral disk disease. Intervertebral disk disease can be a very distressing condition to both the owner and dog alike, and therefore, many dog owners wish to provide their dogs with quick relief through several prescription medications, and methocarbamol for dogs with IVDD is often one of them.
Intervertebral Disk Disease in Dogs
Intervertebral disk disease is a condition that involves a herniated disc of the dog's spine. To better understand what happens, it helps to take a little lesson in anatomy.
A dog's backbone or spine is meant to provide support to the body and protects the dog's spinal cord, a column of nerves meant to connect the brain to the rest of the body. This collection of nerves branches off to the rest of the dog's body and provides dogs with a “communication highway” which relays messages from the brain to the the body.
The spine is composed by several bones known as vertebrae. Vertebrae are stacked nicely next to each other so that a hollow tube allows the spinal cord to pass through. In between each vertebrae, is found what's known as an intervertebral disc, composed by a fibrous outer part, and a soft, spongy type of material which acts as a cushion within the interior part, preventing the vertebrae from rubbing against each other.
To better understand what happens when dogs suffer from IVDD (or herniated disc), it helps to compare the dog's disc to a jelly donut. The fibrous outer part is the dough, while the soft, spongy substance in the middle is the jelly. In predisposed dogs as they age, the outer layer of the disc becomes weak and loses its ability to contain its "jelly." On top of this, the jelly becomes chalky. In these dogs, the jelly part of the disc, instead of compressing and expanding as it's supposed to, gets squeezed and extrudes leading to a "herniated disc."
The herniated material, therefore ends up pressing on the spinal cord, leading to significant pain and even decreased nerve function. Affected dogs that are treated conservatively are often put on with non-steroidal anti-inflammatory drugs and painkillers (NSAIDs) or steroids and painkillers. NSAIDs and steroids should never be used together.
The primary goal of all these drugs is to reduce pain, inflammation and improve nerve function. The goal of surgery (laminectomy) instead is to remove the herniated disc material so to stop it from pressing on the spine. Surgery of the dog's neck or back is often needed when there are neurological deficits
Methocarbamol for Dogs With IVDD
When a disc herniates, and therefore, ends up compressing the spinal cord, there is significant irritation and inflammation as a result. Muscle spasms, the involuntary tightening of muscles, can occur secondarily to this injury.
What happens exactly is that, the herniated disc ends up pressing against a nerve, causing the surrounding dog's muscles to involuntarily contract.
On top of this, the dog's body, in response to the pain, instinctively attempts to immobilize the affected area, but this leads to further tightening of the surrounding musculature leading to painful muscle spasms.
Methocarbamol for dogs with IVDD can turn out helpful, considering that this drug is a muscle relaxer. Also known as Robaxin, methocarbamol is prescribed to reduce muscle spasms due to inflammatory and traumatic conditions such as back issues, traumatic sprains, and following recovery from surgery.
This drug is not thought to work on the contracted striated muscles directly, but rather on the central nervous system, as a depressant and sedative. Among humans, this drug works rather swiftly, with peak levels being reached two hours following administration.
For dogs suffering from IVDD, use of the drug methocarbamol is not enough. The pain is quite severe and dogs manifest pain in various ways (whining, yelping, increased heart rate, increased respiration, panting, inability to move, lameness trouble sleeping). Affected dogs should therefore also be on anti-inflammatory drugs such as Rimadyl, Previcox, Deramaxx, pain medications (tramadol, gabapentin), and muscle relaxants (methocarbamol), until the pain and inflammation is under control.
"Diazepam and methocarbamol are useful to control the pain associated with muscle spasm secondary to nerve root compression. Gabapentin can be very useful for pain of neuropathic origin, and tramadol also has a role in these patients. " ~Christopher L. Mariani, DVM, PhD, DACVIM
Side Effects of Methocarbamol for Dogs
Methocarbamol is a drug that is FDA approved for use in dogs and cats. It requires a prescription from the vet. When prescribed in normal doses, methocarbamol is safe and relatively nontoxic. As with other drugs though, it must be pointed out that methocarbamol is not without its list of side effects.
The most common side effect reported is sedation. Because methocarbamol works by depressing the central nervous system, it shouldn't be used in conjunction with other medications that work as central nervous system depressants.
Less common side effects include excess salivation, drooling, vomiting, loss of balance, weakness, staggering. These side effects are mostly seen with intravenous injections.
Methocarbamol should not be used in pregnant dogs or in puppies unless the benefits outweigh the risks. This drug should be avoided in lactating dogs considering that it isn't clear whether this drug is excreted in milk. In senior dogs, methocarbamol should be safe to use, although the injectable form should be avoided in senior dogs with decreased renal function due to the fact that the injectable form contains polyethylene glycol.
Overdoses lead to significant central nervous system depression, causing excessive sedation, lethargy, staggering. Dog owners suspecting an overdose, should report to their veterinarian or the ASPCA Animal Poison Control Center. Dog owners should have the medication bottle handy and know the weight of the dog so to answer specific questions about toxicity.
As seen, methocarbamol for dogs with IVDD is a good addition to other medications that help control the pain and inflammation associated with IVDD. Fortunately, the muscle spasms, although annoying, tend to subside with time.