Maria has a dog with Demodicosis and has a question about her:
“My Pug has been under treatment for three weeks now. I don’ t see her getting any better. On the contrary I see more patches everyday. When will I see a difference. Will she grow hair again on the patches?”
Maria, Demodicosis can be a challenging disease to treat. It is not unusual for patients to look worse before they look better.

First, three weeks is not enough time to see any improvement. New skin cells “born” today don’t reach the outside of the skin until about 30 days later. Therefore, the “improvement” you’re looking for is still just under the surface.
Second, some pets have lots of canine Demodicosis mites, some have only a few. Those with many mites take longer to get better.
Third, Demodicosis patients have secondary bacterial infection called pyoderma. Those with pyoderma must be treated with antibiotic therapy, along with a mite-killing treatment.
Fourth, dogs with a strong immune system get well from Demodex canis faster than those whose immune system is not “helping out.”
All that to say that there isn’t an easy answer to your question. You will know more as your pet’s doctor evaluates the response to treatment, and as time passes with progression of treatment.
The good news is that most dogs overcome this condition and, in the absence of scar tissue, grow a new, beautiful coat of hair.
See you tomorrow, Dr. Randolph.