blue skin patch- blackening of fur

[Lindachau]

Hi. I have a 2yearold Shihtzu mix and he has one quarter sized blue patch of skin above his tail and the fur on the blue skin  is completly black. it hasn't grown bigger or smaller. he doesn't bite or scratch. should i be worried?

[Aleda M Cheng, D.V.M., C.V.A]

I don't believe that it is anything to be worried about, and is probably related to atopy (allergic skin disease), which is extremely common and non life-threatening!  So please calm down and have your veterinarian take a look tomorrow!

[Lindachau]

he had allergies this summer. the vet gave him a shot and some meds but his allergies were ongoing. i bathed and dried him last night and noticed a little blue speck was forming on the base of his tail and the hair is again only turning black on that little spot. could this kill him? i'm going to go make an appointment now. if it is either of these skin conditions is it curable? or forever

[Aleda M Cheng, D.V.M., C.V.A]

Does your Shih-Tzu have allergies that you know about?  It could really be anything: dermatophytosis (fungal skin infection), Malasszia skin infection (yeast infection), staph pyoderma (bacterial skin infection), or a large freckle, etc.  I would have it examined by your veterinarian.  Your vet will probably want to do a woods lamp check, skin scraping, cytology, etc. Or, the vet will take one look and know what it is.  But just to be safe have it checked.