Hello I am Dr. Joey. Thanks for trusting me to help you and your pet today. I am a licensed veterinarian with over 16 years of experience. I look forward to working with you. I apologize for the delay in an expert responding to you.
Sounds like you have two different problems going on here. For the eye issue, this is most suspicious to be caused by the Feline Herpes Virus. It causes the black debris int he corners of the eyes, sometimes even look to be draining from the eyes and also can be in the nostrils. This is highly contagious between cats.
Second, we have the hairless lesions. The number one suspicion for a hair loss spot that seems to be spreading but is not itchy is ringworm. However, with ringworm the skin usually looks smooth with no hair regrowth and is nonirritating to the cat (you do not notice grooming the area all the time). If you do notice a high level of grooming and there is a raised spot, then this is more likely to be something else such as an allergic skin disease issue.
So, what could you try at home if you were unable to have him seen? If the cats have a relapse of the eye issue or it is not entirely resolved, I recommend start them all on a l-lysine supplement daily. This helps a cat fight the virus without any side effects. Here is an amazon link to a product which I trust and know works well; you can get either the powder which is in the link or it also comes in a gel: http://www.amazon.com/Vetoquinol-410633-Viralys-Powder-100gm/dp/B000FULBT4/ref=sr_1_1?ie=UTF8&qid=1451043429&sr=8-1&keywords=viralys
For the hairless lesions, if they are as I described for ringworm, then you could safely try treating over-the-counter with a CREAM made for athlete's foot in people with the active ingredient of either laminal (terbinafine) or miconazole. You apply twice daily. This may take 6-8 weeks to clear doing it this way. If this is ringworm, then remember this is highly highly contagious to people. So please practice good hygiene with handwshing whenever you handle the cats.
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