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Why is my dog scratching, has black, crusty skin, and is lethargic?

Updated On September 23rd, 2025

Pet's info: Dog | Miniature Schnauzer | Male | neutered | 5 years and 6 months old | 20 lbs

mini schnauzer biting and scratching himself, pustules turning into crusty skin flaking spots on under belly, skin turning a black colour instead of usual pale white, his demeanour quieter than normal, maybe lethargic.

2 Answers

Most Helpful Answer

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Answered By Dr. Massimo Orioles, DVM, Cert AVP, MRCVS

Veterinarian

Published on June 12th, 2017

This is probably due to an allergy, although it could also be infection or mites. First of all, in order to rule out skin parasites, you will need to treat with a high quality flea treatment (advocate or advantage), then ask the vet to perform a skin scrape - this might reveal an infection or a mite infestation. If all of those came back negative, the next step is to treat the allergy symptomatically and try to discover the cause of the allergy. Three main type of allergies are usually affecting pets: food allergies, flea and parasite related ones and environmental type (allergens coming from trees, pollens, dust etc etc). Some medications can be given by the vet in order to repair any possible skin lesions (like steroids and antibiotics). Please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.

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Other Answers

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    Answered By Dr. Leigh, DVM

    Veterinarian

    Published on

    It sounds like he might have allergies with a secondary bacterial skin infection. He should be examined by a vet for treatment. He may need an antibiotic, anti-histamine, and a corticosteroid to help give him some relief. You could also bathe him with a medicated dog shampoo and see if that helps but it sounds like he needs some oral medications to help.

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