HELP!!

This is a dog that just showed up to us months ago, yes we had her chip read and the address was a vacant home 3 hours away and we posted everywhere trying to find owner, no luck. She’s an awesome dog and was already house trained and is a year and a half old. See the places on her side. What is that and what do we do?  We were told just Benadryl and nothing else to do. I wanted second opinion. So thank you in advance and God Bless. 

Hello - thats quite extensive and needs veterinary treatment.  Benadryl is an anti-allergy drug, so I deduce from that that your dog may be showing allergy symptoms and signs of discomfort - scratching etc?  If so, it is clearly not working - there are more appropriate treatments for allergy nowadays, and scratching can cause superficial infections etc that may need to be treated topically.  However, unless it has been diagnosed by a vet, do not assume that this is an allergy - your vet would start by ruling all manner of parasites out.  For cases that are not itching sufficiently to have caused this amount of hair-loss, consider ringworm, demodex and endocrine disorders.  Tests would be needed.  If Ringworm is a real possibility, there will be steps you need to take to protect yourself and anyone young or otherwise immunocompromised and therefore do speak to your vet sooner rather than later.  Some female dogs experience hormonal changes that lead to non itchy fur loss but it doesnt usually take on this sort of appearance.   It is common, on this forum, for owners to want to jump from a symptom to a treatment - antihistamines as a treatment for itchiness or antifungals for baldness.  But what needs to happen is to identify the cause of the symptoms ; this way, you can treat the problem that is actually causing the hair loss and then the treatment is more likely to solve the symptoms.