Electromyography

What is EMG?

EMG is an abbreviation for electromyography or electromyogram. This is a procedure in which small needles or electrodes are inserted into the muscles to record the electrical signals generated during muscle contraction. These signals are then displayed on a screen or printed out on paper. Based on the shape, size and frequency of the signals, a vet can determine whether the muscles are functioning normally or whether there are signs of damage or disease.

When is EMG used in dogs?

EMG is used in dogs when they show symptoms that indicate a disorder of the nervous or muscular system. These include, for example

• Paralysis or weakness in the limbs
• Tremors or cramps
• Muscle atrophy or hardening
• Pain or discomfort in the muscles
• Behavioral changes or disturbances

EMG can help to find the cause of these symptoms and distinguish between different conditions. For example, EMG can show whether paralysis is caused by damage to the spinal cord, nerve roots, peripheral nerves or the muscles themselves. Some of the most common conditions that can be diagnosed with EMG are

• Myasthenia gravis: an autoimmune disease in which communication between the nerves and muscles is disrupted.
• Myopathies: Diseases that affect the structure or function of muscle fibers.
• Neuropathies: Diseases that affect the structure or function of nerve fibers.
• Radiculopathies : Diseases that affect the nerve roots that emerge from the spinal cord.
• Polyneuropathies: Diseases that affect several nerves at the same time.

How is EMG performed on dogs?

EMG is usually performed on dogs under general anesthesia to avoid pain and prevent movement. The vet selects the muscles to be examined and then inserts a thin needle or surface electrode into the muscle. The needle or electrode is connected to a device that records and displays the electrical signals. The vet can then stimulate the muscle by gently tensing it or applying an electrical impulse. The response of the muscle is measured and analyzed. The process is repeated for each muscle until all relevant information is collected.

What are the benefits and risks of EMG in dogs?

EMG has several advantages as a diagnostic method in dogs. It is:

• Non-invasive: it does not require surgery or tissue removal.
• Fast : It only takes a few minutes per muscle.
• Accurate: It can detect very small changes in muscle activity.
• Specific : It can distinguish between different types of nerve and muscle disorders.

However, EMG also has some risks and limitations in dogs. It is:

• Painful: It can be uncomfortable for the dog when the needles or electrodes are inserted into the muscles.
• Risky: It can lead to bleeding, infection or nerve damage if the needles or electrodes are placed incorrectly.
• Expensive: It requires specialized equipment and professionals.
• Dependent: It depends on the quality of the anesthesia, the positioning of the dog, the choice of muscles and the interpretation of the results.

What should you consider as a dog owner?

If your dog needs EMG, there are a few things you should keep in mind to help him get through the examination well. You should:

• Keep your dog sober before the examination to reduce the risk of vomiting or aspiration.
• Keep your dog warm after the examination to avoid hypothermia.
• Observe your dog after the examination to detect possible complications such as bleeding, swelling or paralysis.
• Provide your dog with painkillers after the examination if they show signs of discomfort.
• Ask your vet any questions you have about the EMG results or your dog's treatment.