Demodex Mange in young dog

Question
Hello,

My dog was just diagnosed with generalized demodetic mange through a skin scraping. He's about 23 months old, with the onset of symptoms (which the vet thought were allergies) at around 12 months. We adopted him from a shelter so I don't know if he had symptoms earlier.

We had been struggling with "allergies' that just wouldn't go away and he was taking 2 pills of Temaril-P a day plus benadryl. After two ugly hot spots where he lost all hair and was starting to scratch to the point of bleeding, the vet performed the skin scraping and found several mites in each slide, which he says indicates a serious case.

The treatment is 30 days of Cephalexin, up to 10 weeks of ivermectin (0.5ml for a 34lb dog after initially lower doses), baths in pyoben shampoo, and 25mg of Benadryl three days a day. The benadryl is because of seasonal allergies, indicated by eye discharges and ear infectons prior to this.

My questions is: about how long until we see any improvements? Is my dog too old to get this disease, indicating a severely compromised immune system or is this still considered a puppy onset? Is there anything else I can give him to help boost his immune system after so many months of Temaril-P?

Thanks!

Answer
Adult onset demodex is hard to cure.  The skin may look better after 30 days of ivermectin, but it may return at some point.  You are right, the dog's immune system is depressed and that's why the mange mites can reproduce.  Atopica for allergies is reported to be safe in demodex mange.