Gabapentin Side Effects in Dogs

By Angela Libal

Gabapentin is marketed under the brand name Neurontin and is available as a generic. It is a synthetic prescription pain medication used to treat arthritis and other conditions that cause chronic pain. Occasionally it is used to treat seizure disorders. Use in dogs is not approved by the US Food and Drug Administration, but is common veterinary practice. Side effects are typically mild and include minor sedation and ataxia, or poor balance and lack of coordination.

What Gabapentin Does

Gabapentin has a similar structure to the neurotransmitter gamma-Aminobutyric acid, yet does not interfere with this transmitter in the brain. It is considered safe in dogs and works best when combined with nonsteroidal anti-inflammatory drugs. While generally prescribed to treat canine arthritis, it is also effective for treating pain caused by nerve damage, or neuropathy, and its symptoms, allodynia, which is pain from typically nonpainful stimuli, and hyperalgesia or pain oversensitivity. Gabapentin is sometimes used to treat cancer pain and epilepsy of unknown origin.

Possible Side Effects

Common side effects of gabapentin include mild lethargy, drowsiness, stumbling, incoordination and depression. Severe incidence of these may signal an overdose. Gabapentin is not appropriate for all dogs. For example, it is rarely used in pregnant or nursing animals because it can cause miscarriage and birth defects, and because it transfers into the mother's milk. Its use also may be contraindicated by kidney or liver problems. Liquid forms of gabapentin for human use should not be used in canines because they contain xylitol, which is toxic to dogs. Other medications may interact with gabapentin: antacids decrease its effects, while the pain killers hydrocodone and morphine may increase them and lower the threshold for overdose. Gabapentin use must not be ended abruptly and it may not be appropriate for the long term. Sudden withdrawal can cause seizure and severe pain episodes, while long-term use leads to decreased effectiveness and may increase the risk of developing pancreatic cancer. Be sure to consult with your vet on its proper use and any side effects your dog may be experiencing.