As many a dog owner living in porcupine country has discovered, ignoring any of the porcupine's ample warning signs can have agonizing consequences for an overly inquisitive or aggressive pet. The end of each porcupine quill is made up microscopic, backward projecting barbs that serve to work the quills ever deeper into the flesh. This painful process is further aided by the greasy coating on each quill. Once imbedded, quills cannot easily be pulled out.
Serious injuries, even fatalities, can occur to both wild and domesticated animals who have come in contact with a porcupine, particularly if the eyes, mouth, or throat are afflicted. If your pet has been "quilled," seek immediate treatment by a veterinarian. This will ensure that the quills are removed completely and correctly, with as little discomfort as possible, and that antibiotics may be prescribed if necessary. "Quilled" humans should consult a physician for the same reasons.
Because the plant materials eaten by porcupines have a low sodium content, porcupines may hunt far and wide to satisfy their dietary need for salt, particularly in the springtime. This natural urge often brings them into conflict with people. Due to the salt found in sweat, almost any object that has been handled by humans may be fair game for porcupine consumption—including clothing, wooden tool handles, and furniture. The wooden parts of structures that are gnawed are usually bonded plywood that contains a layer of glue that attracts porcupines. Car tires and hoses may also be chewed because of their mineral content or coating of road salt. Unfortunately, many porcupines meet their end in roads, to which they are naturally attracted due to winter salt use.
Porcupines occasionally damage structures and items used in outdoor work or recreation, and are sometimes responsible for damage to trees. Where individual trees need to be protected, a metal band about 24–30 inches in height can be placed around the trunk of a tree about three feet off the ground. This will prevent the tree from being climbed and is likely to be very effective. However, don't leave the bands on trees for any longer than necessary. Insects may accumulate, lay eggs, or overwinter beneath them, and the trunks of sensitive trees may scald if bands are removed after a long period and sun falls on the exposed bark.
A capsaicin-based, "hot sauce" repellent is registered for use against porcupines and may be used for things like combating porcupine damage to plastic tubing, such as that used for maple syrup collection. Preservatives, such as copper napthanate and pentachlorophenol, used in the manufacture of plywood, also appear to have some repelling properties, even though they are not registered as animal repellents.
