Trigeminal Neuritis (TN) is a rare neurological condition affecting the trigeminal nerve, which wraps around the face, controlling functions such as the eyes’ blinking reflex and the jaw’s ability to open and close normally.
Dogs affected with TN will typically present with blinking deficits and a “dropped jaw,” where the lower mandible constantly hangs open. The dog often exhibits abnormal mandibular coordination and sensation, but in the early stages, the animal does maintain some control of the jaw.
Another less obvious symptom involves the blinking reflex, which is abnormal in dogs that are suffering from this condition.
“We’re not sure what causes TN in many cases. Any trauma or damage to the trigeminal nerve – be it from an impact or injury or from a tumor – can lead to TN, but in a significant portion of canine cases, this is an idiopathic condition where the precise cause is unknown,” explained Dr. Michael Levine, DVM, a practicing veterinarian and professor of veterinary medicine.
Due to its rarity, TN is most often diagnosed following an examination by a veterinary neurologist. Additional diagnostic testing, like an MRI, is also routine since TN can be a secondary condition, stemming from a tumor or a skeletal abnormality.
Fortunately, in a vast percentage of cases, TN is temporary, often disappearing within a couple weeks of the initial onset.
“In a majority of TN cases, treatment consists of anti-inflammatory steroid drugs like prednisone, which serves to lessen inflammation involving the trigeminal nerve. Injuries and other abnormal contact with the nerve cause inflammation, so the steroids decrease that inflammation and symptoms improve. Certainly, it’s not a cure-all, but we do see improvement in many TN patients,” Dr. Levine explained.
Supportive care is also helpful for dogs suffering from a bout of TN. Feeding soft foods from a raised food bowl can make eating easier, while teaching a dog to drink from a large water bottle – like the models typically used for rabbit and ferret cages – can make for easier drinking in TN sufferers.
In a small number of dogs suffering from TN, the condition is permanent, leading to atrophy of the facial muscles and an inability to eat and drink independently. For those pets, it’s necessary to provide more comprehensive supportive care, like hand-feeding meals, daily subcutaneous fluid injections, and hydrating eye drops.
Fortunately, this condition is fairly uncommon and permanent TN cases are even rarer. But even in those dogs who suffer from TN long term, there is hope. Dr. Levine concluded, “With supportive care, long term sufferers can live a happy, fulfilling life – it just takes a bit of creativity and the obstacles of TN can be overcome.”