I was on a casual hike yesterday and my dog bit a porcupine. I will cut right to the chase about what to do, just in case you are scanning for quick info on quills in a dogs face.
Chances are your dog is pawing at its face trying to figure out what is happening. In order to prevent the porcupine quills from going deeper this needs to be prevented.
You should likely get on the phone immediately to find out if a vet is available. If your dog has a serious amount of quills. If there are porcupine quills preventing your dog from closing is mouth. What I did was pull all of the porcupine quills from inside her mouth as soon as possible. I could see one that was laterally in her lip and was about to be out of sight. I could barely see the end of it. Before I went to the vet I made sure to remove any that could potentially become a huge problem. That depends on how far of a drive you have. I had almost a full hour drive to an emergency veterinarian.
They will put your dog under and remove the quills. This will allow them to examine closely for deeply embedded porcupine quills that would have gone not noticed. There is a good possibility that there are some quills buried deep if it was a smaller porcupine with really small thin quills.These seem to really slide in deep fast. The porcupine my dog got into yesterday was only about 5 pounds. My dog didn’t bite it, she just nudged it to encourage it to play with her. Because of how spastic she went there was one quill that was an inch long and was in her lip entirely buried. The rest were visible on her nose and chin. I had an Irish setter quite a few years ago that bit a porcupine. That was a much worse case than what my dog yesterday experienced.
There is no sure fire method to total avoidance of porcupines, but you can minimize the chance for an encounter by: