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Medication details

  • Medication type: Sedative, Skeletal muscle relaxer
  • Form: Tablet, Injection
  • Prescription required? Yes
  • FDA approved? Yes
  • Life stage: All
  • Brand names: Robaxin, Robaxin-V, Robaxin-750
  • Common names: Methocarbamol
  • Available dosages: 500 mg or 750 mg tablets; 100 mg/ml injection
  • Expiration range: 2-5 years, depending on packaging

If you have ever had a pinched nerve, you might be familiar with the pain that can accompany muscle spasms. There are a number of conditions that can lead to muscle spasms in dogs, and these conditions are often treated with methocarbamol. 

Methocarbamol can be used to treat muscle spasms attributed to a number of different causes. Some possible causes of muscle spasms include muscle inflammation or injury, spinal cord disorders, tetanus infection (also referred to as “lockjaw”), and some toxicities (strychnine and some toxic mushrooms). 

Perhaps the most common use of methocarbamol in dogs, however, is in the treatment of intervertebral disk disease (IVDD). Although the benefits of methocarbamol in the case of IVDD are somewhat controversial, many veterinarians prescribe methocarbamol to alleviate the painful muscle spasms associated with disk disease. 

What Is Methocarbamol?

Methocarbamol is a muscle relaxer used to treat skeletal muscle spasms in dogs that may be caused by trauma, inflammation, infection, or toxicity. This drug only affects signals that are relayed to skeletal muscle, so methocarbamol doesn’t affect the smooth muscles present in the intestines, the bladder, and other parts of the body. In addition to causing muscle relaxation, methocarbamol also has a mild sedative effect. 

Methocarbamol was initially approved for human use in the United States in 1957. It is still a commonly-used medication in human patients and is often prescribed for the treatment of lower back pain. 

In addition to its use in humans, methocarbamol is also widely used in veterinary medicine. It is prescribed regularly by veterinary practices throughout the United States. Pet owners can typically obtain this medication from their regular veterinarian if their pet needs it, without any need for a specialist visit. Most veterinarians keep this medication in stock, although in some cases a prescription may be called into a human pharmacy for pickup. 

What Does Methocarbamol Look Like?

Oral methocarbamol typically comes in the form of a white, uncoated tablet, which may be oval or round in shape. Coated tablets are also available and may be used in some situations. 

How Does Methocarbamol Work?

Dachshund at a veterinary office

Methocarbamol acts on neurons within a dog’s spinal cord, decreasing abnormal nerve impulses that trigger muscle hyperreactivity. The exact mechanism by which methocarbamol exerts this effect is not fully known. 

Unlike some other muscle relaxers, methocarbamol does not have any direct effect on muscle cells at normal doses. It only disrupts abnormal signals within the spinal cord. This means that methocarbamol can stop muscle tremors, spasms, and hyperreactivity without significantly interfering with a dog’s normal muscle activity. 

What Is Methocarbamol Used For in Dogs?

Methocarbamol is used to treat a number of muscular conditions in dogs. Any condition that causes muscle tension or spasms may potentially be treated with methocarbamol. 

In some cases, muscle spasms are caused by inflammatory or traumatic conditions that affect the muscles directly. Intervertebral disk disease and spinal cord injuries may cause muscle spasms due to nerve compression, and tetanus also causes widespread muscle spasms in dogs. Finally, there are a number of toxins from pesticides and poisonous mushrooms that can cause muscle spasms in dogs.

Methocarbamol may be prescribed to dogs to treat the following conditions:

  • Muscle inflammation
  • Muscle trauma
  • Muscle strain
  • Muscle sprain
  • Intervertebral disk disease 
  • Spinal cord injury
  • Tetanus
  • Strychnine (pesticide) toxicity
  • Tremorgenic mycotoxin (mushroom) toxicity

Methocarbamol Side Effects in Dogs

Tired dog sleeping on bed

In most cases, methocarbamol produces minimal side effects. Some dogs may experience more pronounced sedative effects than expected, but these effects are typically short-lived and resolve as the medication begins to wear off. 

In dogs receiving very high doses of methocarbamol, muscle weakness may be seen. These dogs may have trouble standing or walking. 

Like any other oral medication, methocarbamol can also cause vomiting and diarrhea, although this is uncommon. Giving methocarbamol with food may reduce the risk of nausea. 

Methocarbamol can safely be given long-term, with appropriate veterinary monitoring.

Potential side effects of methocarbamol in dogs include:

  • Sedation
  • Muscle weakness
  • Trouble standing or walking 
  • Vomiting
  • Diarrhea

Reactions With Other Drugs and Medications

Methocarbamol can be safely combined with a number of other medications. Given its applications in treating muscle spasms and back pain, methocarbamol is often used in combination with sedatives such as trazodone (to limit an injured dog’s activity), pain medications such as gabapentin (to decrease nerve pain), and anti-inflammatories such as prednisone and non-steroidal anti-inflammatory drugs (to alleviate inflammation). 

When methocarbamol is combined with sedatives, dogs may experience more sedation than they would experience with either drug alone. Therefore, the dosage of one or both drugs may need to be altered to minimize sedation. 

Methocarbamol can also interfere with the activity of pyridostigmine and other medications used in the treatment of myasthenia gravis. Dogs with myasthenia gravis that is managed with these medications may experience a relapse if they are started on methocarbamol.

Methocarbamol Dosage for Dogs

white pills on blue background

Methocarbamol dosing is determined primarily by a dog’s weight. Dogs with strychnine toxicity or tetanus may be prescribed very high doses of methocarbamol, while a dog with back pain due to intervertebral disk disease will typically be prescribed a relatively low dose. 

Always administer the dose that is prescribed by your veterinarian. Do not change your pet’s methocarbamol dose without first speaking to your veterinarian. 

What if My Dog Misses a Dose of Methocarbamol?

Methocarbamol is typically administered every 8-12 hours. If your dog misses a dose and you realize it within a couple of hours of the missed dose, you can administer the missed dose at that time and then wait 8-12 hours before administering the next dose. 

Alternatively, you can skip the missed dose completely and wait to administer your dog’s next dose of methocarbamol according to your original dosing schedule. 

Price of Methocarbamol for Dogs

Generic methocarbamol is an inexpensive medication. A two-week course of methocarbamol for an average-sized dog typically costs $30 or less. The brand-name version is more expensive. For this reason, most veterinary practices stock only the generic version. 

Methocarbamol Storage Instructions

Methocarbamol tablets can be stored at room temperature. They do not require refrigeration or other special handling and can be stored on a countertop or in a cabinet.