I have never heard of trigeminal neuropathy until this year. We had a dog get it. One day he was fine the next day his lower jaw was hanging and he couldn’t use it. We took him to the vet expecting the worse and they diagnosed him with trigeminal neuropathy. After talking with the vet they said it happens on occasion but they have no idea what causes it. They assured us in a couple weeks he would regain use of his jaw. After a couple weeks of feeding him by hand and helping him drink he regained the use of his jaw. Everything went back to normal, kind of scary but in the end all was well.