By Christie Long
Sarcoptic mange, or scabies, is a skin condition caused by infestation with a tiny organism known as a mite.
Mites are not the same as lice, fleas or other insects. They are actually related to the spider. A female mite burrows its way into the skin forming a tunnel and leaves her eggs there. The offspring hatches, and the larva move up to the skin where they mature. The movement of these creatures on the skin produces an intensely itchy sensation, and the burrowing creates severe inflammation, so dogs and cats affected by them scratch at themselves like crazy. Because mites like sparsely haired areas, dogs are usually affected on the underside of their abdomen, ears and elbows. Cats have lesions on their faces and ears.
We used to not think too much about sarcoptic mange in Colorado, since we just didn’t see much of it for reasons probably related to our climate. However, recently we are seeing more cases of it in certain situations. Dermatologists theorize that perhaps dogs are being exposed to the mites through contact with foxes or coyotes, both of which are members of the canine family that are affected by the same mite. Although owners aren’t necessarily reporting direct contact between their dogs and these wild animals, it’s thought that other factors might be involved.
Here’s the scenario: A dog that is being treated for severe skin allergies, usually for an extended period of time, is on drugs to suppress the immune system and control the allergic response. The dog is doing pretty well, the itching is controlled, and then all of a sudden one day the dog becomes intensely itchy. The veterinarian and the owner assume it’s an allergic flare-up and increase the dose of immunosuppressive drugs. However, instead of getting better, the dog gets worse.
It’s thought that these pets on chronic immunosuppression are getting sarcoptic mange because they have little or no ability to effectively fight off an infestation on their own. Because we almost never see this disease in Colorado, veterinarians may be overlooking the possibility that a very itchy dog could have it. They just think that the pet must be having an allergy attack.
Mites are typically diagnosed by scraping the skin with a scalpel blade and looking for them in the debris under the microscope. It’s estimated that about 50 percent of the time, mites are actually seen with this test. That means that the other 50 percent of the time they are in fact present but undetected. Because of this, veterinarians will often treat pet for sarcoptic mange, even it they can’t necessarily prove it’s there.
Scabies is still relatively rare, especially compared with other causes of itching in dogs and cats, such as allergies. But if your pet suddenly becomes intensely itchy for no apparent reason, especially if it is already being treated for allergies, it’s worth it to discuss with your veterinarian whether it makes sense to look for a mite infestation.
Christie Long is a veterinarian at the VCA Animal Hospital in Fort Collins, CO. Long left her job in software sales in 2000 to travel for 13 months. Along the way, she was touched by the plight of the animals she saw and somewhere in the Nepalese Himalayas she vowed to return to school to become a veterinarian. While she often finds end-of-life situations heart-wrenching, she considers herself blessed to be called upon as a trusted adviser to families during difficult times. Dr. Long’s family includes her husband and travel partner, Wiley, their 5-year-old son, Wiley IV, their dogs Pancake and Gizmo and cats Sneaky and Sidh.