Methocarbamol is a muscle relaxant that is certified and approved by the US FDA for use in dogs as well as other pets and livestock whenever appropriate. It is often indicated in conditions where muscle spasms are a presenting feature such as the ingestion of toxic substances and other health conditions. It is a very potent relaxant of skeletal muscles, has long acting therapeutic effects, and is considered to be non-toxic, a feature that is welcomed by many dog owners considering that the principal action of methocarbamol is in the central nervous system. Being a drug that is approved by the FDA and with serious clinical implications, its use warrants a valid veterinary prescription and the adherence to dosage administration guidelines.
The clinical indications of methocarbamol are directly related to its muscle relaxant activity. While it can be used for almost any other type of condition where the major presenting sign is muscle spasticity, only a few conditions have been cleared for its definitive use. These include the following.
- Conditions of the spinal cord
The spinal cord is part of the central nervous system conveying electrical impulses to and from the higher cortical regions of the brain where motor control is integrated and delivered to and from the various nerves of the peripheral nervous system. Unfortunately, injuries or even diseases to the vertebrae and the spinal cord itself can produce spasms in this region.
For example, intervertebral disc syndrome does not typically involve the muscles of the vertebrae. The major issue is in the discs that provide cushion in between vertebrae leading to herniation or bulging of the spinal cord into the intervertebral space causing pain, paralysis, and even nerve damage. Methocarbamol can help lessen the spasticity of the surrounding tissues to help lessen the impact of intervertebral disc syndrome.
Methocarbamol is also indicated in the management of compressive myelitis as well as spinal cord injury. However, in the case of SCI, it is important that the spinal cord remains intact for methocarbamol to be able to exert its therapeutic effects.
- Traumatic injuries
Dogs are very active pets. They love jumping around even from an area of considerable height. Sprains and strains of the muscles and ligaments can cause microscopic tissue injuries that can bring about intense pain. By controlling muscle spasms, pain should be reduced allowing for more efficient mobilization of the musculoskeletal and articular apparatus.
- Problems of the canine musculoskeletal system
Myositis describes an inflammation of the muscles which can actually be brought about by a variety of conditions including injury, autoimmune disease, and infection. Since we’re talking about pooches, the most common cause of myositis will be either injury or infection. While methocarbamol doesn’t address the injury or infection itself, it does help lessen the severity or intensity of the pain that is associated with tissue inflammation.
Methocarbamol is not only indicated in myositis. It is also recommended in the management of fibrositis, synovitis, and bursitis. Fibrositis involves fibrous connective tissues especially those located on the back of dogs. This also produces pain and stiffness. When the synovial membrane lining joints get inflamed, it is known as synovitis. Bursitis technically refers to irritation or inflammation of the burse, the sac that is filled with lubricant to make sure there is no friction in between tissues of the bones, tendons, skin, and muscles.
- Muscle spasms secondary to surgery
There is always tissue injury in surgery. Pain is always an issue. As such, methocarbamol can also be used to help manage the various muscular spasms that typically occur as the surgical wound starts to heal.
- Miscellaneous conditions
Canine tetanus and strychnine poisoning are special concerns among dogs. While canine tetanus is not really that common in dogs especially when compared to the incidence of tetanus in humans, it does occur. Strychnine is also a major issue especially among households that use a variety of pesticides that contain such toxic chemicals. Methocarbamol is indicated in the management of muscle spasms brought about by strychnine toxicity.
Benefits of Methocarbamol
It is without a doubt that the benefits afforded by methocarbamol are directly related to its muscle relaxant effects. The following are just some of the more common benefits of using such medications in dogs.
- Promotes muscle relaxation for optimum comfort
Muscle spasms can be especially debilitating. By reducing the intensity of skeletal muscle contraction, dogs are able to feel more comfortable.
- Alleviates pain
Pain is a natural result of tissue injury. As muscles undergo forceful contractions, they also pinch on nerves which can produce sharp pain. Methocarbamol can help lessen the severity of pain by allowing the muscles to relax.
- Allows proper healing to take place
While this is not readily apparent, forceful uncontrolled contractions of skeletal muscles use the body’s energy stores. This can deplete the body of nutrients needed for the more effective repair and regeneration of damaged tissues. Helping relax muscles can allow the dog’s body to direct all of its reparative energies towards healing.
- Promotes sleep and rest
While definitely not a clinical indication, the action of methocarbamol on the nervous system especially in the promotion of muscle relaxation and the alleviation of pain can help dogs have a more peaceful, quieter sleep and rest. At any rate, this can also help in allowing their bodies to recuperate fully from the disease or illness.
How Methocarbamol Works
While the actual mechanism of action of methocarbamol is still poorly understood, scientists and pharmaceutical experts agree that it may exert its effects on carbonic anhydrase. Laboratory findings suggest that when carbonic anhydrase found in muscles is inhibited or prevented from exerting its action, there is a corresponding increase in the relaxation times of muscle twitching. In other words, the inhibition of carbonic anhydrase in the muscle tissues can lead to pronounce relaxation of that particular muscle group. This is considered to be a peripheral physiologic effect of methocarbamol.
An even more important physiologic process is its involvement in the depression of the central nervous system. Since voluntary muscle contractions receive their motor instructions or signals from the central nervous system, CNS depression can lead to a dampening of the motor response. To be more specific, methocarbamol is known to possess a highly selective action on the internuncial neurons found in the spinal cord. It is its specificity to this type of neuron in the central nervous system that it is able to exert its attenuating effects on the hyperactivity of skeletal muscles. The same specificity eliminates the risk of altering the muscle tone, something that other classes of muscle relaxants are known to produce.
Potential Side Effects
Because methocarbamol works on the spinal cord of the central nervous system, it can produce a variety of side effects that may be considered mild to moderate. However, while it is considered to be generally safe relative to other muscle relaxants of the same chemical class, you can still see any of the following potential side effects.
- Sedation or sleepiness
- Stumbling or unsteady gait
- Loss of appetite
- Dark colored urine
It should be understood that sedation, while considered a side effect, is actually a welcome side effect by many veterinarians. Sedating dogs especially when they are in extreme pain can be also helpful in minimizing the effects of pain, promoting tissue healing, and promoting rest in the ill dog.
There are other side effects that may develop so you might want to ask your veterinarian about these. Additionally, if your dog happens to show any of the following manifestations while taking methocarbamol, it is highly recommended that you stop the therapy and seek immediate consultation with your veterinarian as your dog may already be showing hypersensitivity reaction to the drug.
- Difficulty or labored breathing
- Red, itchy, raised blotches of skin
- Swelling of the face
- Puffiness of the tongue or mouth
Things You Should Know about Methocarbamol
Methocarbamol is a type of muscle relaxant that is similar to other carbamates with the exception of reduced toxic effects. It is duly approved by the FDA and requires veterinary prescription. It is available in both tablet and injectable forms, although the tablet formulation is especially geared for milder to more moderate cases of uncontrolled muscle spasms in dogs. The tablet formulation is available in 500 milligrams with a typical initial dose of 60 milligrams per pound to be divided into 2 to 3 doses on the first day. Succeeding days will require 30 milligrams per pound divided into 2 to3 doses. Clinical reevaluation is a must after 5 days.
What You Should Tell Your Vet before He Prescribes Methocarbamol
Laboratory evaluation of methocarbamol shows that the drug is relatively safe. However, most veterinarians strongly recommend not giving the drug to dogs that are currently lactating or nursing as well as those pooches that are diagnosed to be pregnant. In cases where the benefits outweigh the risks, then methocarbamol may be given to such pets but with extreme caution.
If you have a pooch that is known to be hypersensitive to methocarbamol or any other carbamate type of drug, then this is not a drug that is for your pooch. Make sure to inform your vet about this. Also, any condition that affects the urinary system of your dog will have to be thoroughly evaluated by your vet since methocarbamol is excreted through the urine. This means your dog will require normally functioning kidneys to help eliminate the metabolites of the drug from its system.
How to Give Methocarbamol to Your Dog
The recommended dosage of methocarbamol for dogs is about 20 to 30 milligrams per pound to be administered every 8 to 12 hours for the first day of therapy or roughly 60 milligrams per pound to be divided in 2 to 3 doses. For the succeeding days of the therapy, the dosage is typically adjusted to 10 to 30 milligrams per pound to be administered every 8 to 12 hours or about 30 milligrams per pound in 2 to 3 divided doses.
The reason for the higher initial dose is typically to provide your dog with immediate relief of its symptoms to more manageable levels before the dose is maintained at a safer level. However, take note that the dosage is just a guideline since the correct dosage will still depend on your pooch’s weight, size, age, and overall state of health. If any, one thing is certain, the maximum recommended dose should never exceed 125 milligrams per pound every day.
Also, it is important to continue monitoring your pet. If no clinical response is noted within the first 5 days, clinical re-evaluation is mandatory.
What to Do If You Miss a Dose
In situations where methocarbamol was not administered in time, effort should be exercised immediately to give the missed dose. As long as the time to the next scheduled dosing is still relatively far away, then you can still provide your pooch its missed dose. However, if it is already near the next scheduled administration, don’t make the error of doubling the dose on its next dosing as this can upset the pharmacodynamics of the drug as well as increase the risk of toxicity or overdose.
What to Do in Case of Methocarbamol Overdose
Clinical manifestations that point to methocarbamol overdose or toxicity or even the appearance of hypersensitivity reactions should already push you to bring your canine pet to the vet. If the manifestations are especially severe, an emergency vet facility is recommended. Manifestations of methocarbamol overdose can include absence of reflexes, incoordination and extreme sedation.
Some Drug Interactions
Some drugs do interact with methocarbamol. As such, you should always inform your vet of any drug, supplement, or substance that your pooch is currently taking prior to the initiation of methocarbamol therapy. For instance, gabapentin, antihistamines, tranquilizers, metoclopramide, and opioid narcotics may exacerbate the sedative effects of methocarbamol.
Methocarbamol is a very potent muscle relaxant that can help address muscle spasms in dogs. It’s duly approved by the FDA for veterinary applications mostly in the control of spastic conditions secondary to other disease conditions. It should be noted that the action of methocarbamol puts it as a highly risky drug so you should always make it a point to follow the directions of your veterinarian.