Fido vs Mr. Porcupine: A Prickly Situation

Renee DiPietro, CVT
Veterinary Information Specialist
Permitted Wildlife Rehabilitator 

If you live in Canada, or in the northern, or western Unites States, you may share your outdoor environment with a large (12-35 lbs) albeit reluctant, warrior rodent. The North American Porcupine (Erithizon dorsatum) is an unassuming and mostly nocturnal (though I have seen them out and about during the day) fellow. He goes about his nightly business well protected by his long quills (up to 30,000 per animal). He does have a few predators that can outwit his spiny defense, but the domesticated dog is not one of them. Dogs, especially those with high prey drives, love to persecute porcupines.

Dogs are always on the losing end of the battle in these encounters. Amazingly enough, many dogs are repeat offenders when it comes to tangles with this thorny mammal.

The porcupine’s quills are not used to attack other animals. The porcupine is  a herbivore. He does not need to attack anything. It is a myth that our woodland friend can throw his quills. He can however raise the quills when feeling threatened and back into or lash his spiky tail at attackers in defense. Porcupine quills are a formidable shield against many predators and can be a dangerous, and in some cases even lethal scenario for an over inquisitive or attacking dog. Curious cats are also occasionally participants in these encounters, but these incidences are rare.

The quills are a form of hair that terminates in a sharp, barbed like tip. Hard scales along the tip of the quill function like barbs to hook into tissue and promote quill migration once embedded. The shaft of the quill is mostly hollow. The quills cover the rodent’s body except the feet, face and belly. Porcupines do not move fast. They lumber when they walk and spend time climbing trees. This would make them easy prey if not for the quills which when the animal is assaulted, lodge deeply into the flesh of the marauder.

Once these barbed quills make contact with flesh, they solidly embed. The pain caused by the quills is severe and immediate and dogs tend to respond by rubbing the injured area on any object they can. This is turn, only drives the quills deeper.

The longer the quills remain in place the more solidly they become anchored as body heat encourages their expansion. Additionally, quills can and do migrate. This is where they become life threatening. Migrating quills have been known to pierce and injure vital organs. Quills also work as an effective injection tool for bacteria, and infections caused by piercing quills are not uncommon.

Some dogs do die from porcupine encounters.

Dog vs porcupine incidents are always a veterinary emergency.

People will at times try and deal with this situation at home. I would not advise this for a variety of reason:

  • The dog almost always needs to be put under intravenous or general anesthesia as the quills are usually numerous and must be pulled out, one by one, by hand, carefully, so that they don’t break.
  • If your dog has a face or other body part full of quills, he is in significant pain and cannot be asked to sit politely while you try to remove the tiny spears lodged in his skin. His reaction to pain could be dangerous for both him and for you.
  • The quills break easily and if parts of them remain embedded in the skin or other tissues abscesses can form.
  • Broken quills can also migrate to deeper tissues or vital organs more easily.
  • One of the most common areas for quills to be embedded is in the oral cavity and even down into the throat. These quills can be very difficult to see and remove in an awake dog.
  • Some quills actually require surgical incision into the skin, oral cavity, or other body parts for safe removal.
  • Infection is a common complication and pain will need to be managed even after the quills have been removed.

It is best and safest for your dog, and for you to head immediately to a veterinary clinic no matter the time of day or night when a porcupine encounter occurs.

If you discover your dog has porcupine quills restrain them as quickly and carefully as possible on a leash. A dog that is extremely painful may try to run off and could endanger itself more.

If you are able, bring a helper on the way to the veterinary clinic to try and keep your dog from rubbing the quills. This can minimize self- trauma and the complications that come with many broken quills.

At the clinic your dog will be examined, anesthetized, and your veterinarian, or veterinary technician under the supervision of your vet, will painstakingly remove each quill. Your dog will then be thoroughly examined again for missed quills before being sent home. Antibiotics and pain medications are often prescribed.

The very best idea in this whole scenario is to avoid the situation all together.

There is nothing that makes this experience worth it for your dog, or for you. This hazard is so simply avoided. Enjoy the outdoors with your dog frequently and happily, this This activity is so good for both of you. Trouble with porcupines is easily avoided:

  • Keep your dog on a leash when hiking or walking in the woods or field edges.
  • Don’t allow your dogs to run free outside at any time (so many hazards), but especially at night.

I have friends who have lost dogs to a porcupine defending itself. It is painful and heartbreaking and entirely avoidable and unnecessary. Do your dog and the porcupine a favor, use the leash or fence in the backyard. These measures are simple, effective and easily implemented.

Your dog and your veterinarian will thank you.