Signs of Scabies in Canines

The parasite sarcoptes scabiei causes sarcoptic mange, also referred to as dog mange or canine scabies. The microscopic mites spend their whole lives on the skin of the dog they infest. The female mite burrows deep into the dog's skin, sometimes as far as a few centimeters, and lays her eggs many times while burrowing. The larvae mature and mate. The process repeats until treatment rids the dog of infestation. Symptoms of scabies are easy to spot..

  1. Skin Symptoms

    • As mites prefer skin that has less hair, most external symptoms of scabies present on areas of the dog that have little to no hair, such as the belly or armpits. Mange in dogs will cause small, red pustules that develop yellow crusts on the skin and ooze pus and serum. Left untreated, dog mange will result in loss of hair, as well as scaling and crusting of the skin.

    Behavioral Symptoms

    • Burrowing by mites causes severe itching in affected dogs. This symptom of scabies leads to incessant scratching, which causes trauma to the skin. Sores and bacterial infections of the skin are secondary symptoms of scabies from repeated scratching. Curiously, the itching is theorized to be an allergic reaction to the mite, as it does not appear until several weeks after infestation. If the dog is re-infected, the itching appears immediately, signaling an allergic reaction. Conversely, standard allergy treatments do not decrease the itching, which will become worse in warm conditions. If the sarcoptic mange goes untreated, the lymph nodes will swell and the affected skin will become thickened and darkened from the constant irritation.

    Misdiagnosis

    • Due to the itching, dog mange is often misdiagnosed as a severe inhalant allergy. To avoid misdiagnosis, Dr. Holly Nash of PetEducation.com says that she looks to see if the dog has a history of allergies and whether the symptoms present seasonally or year-round. A dog with year-round itching and no history of allergies likely has dog mange.

    Diagnosis

    • A skin scraping can reveal mites under a microscope for a more accurate diagnosis. Unfortunately, mites only show up in about 20 percent of scrapings from dogs with sarcoptic mange, according to Dr. Nash. Alan Secord echoes Dr. Nash's frustrations with scrapings as a diagnosis tool, stating in his article on parasitic skin diseases for the Canadian Journal of Comparative Medicine that scrapings are almost always negative because owners treat their dogs with home applications and commercial solutions that kill the mites on the surface of the skin. Therefore, he considers a scraping test an almost useless tool for diagnosing sarcoptic mange. Oftentimes, a dog's response to scabies treatment along with the canine's history will determine a diagnosis of dog mange.