Possible Alopecia

My blue heeler and other male cow dog recently started experiencing balding on his flanks after blowing his winter coat for summer. Little about him is that this was his first time experiencing a winter in Indiana as I adopted him from the deep south in GA by the Florida border. The other cow dog lost his hair sooner when the weather started warming up. His life hes been an outdoor dog most his life till recently after having him a year indoors. Both haven't experienced symptoms of cushings or other issues that are related to hair loss.  

Hello - there are various reasons for balding on the flanks.  These can include underlying disease, specifically demodectic mange (demodex mites - diagnosed or ruled out by skin scrape), ringworm (dermaphytosis) and endocrine disorders - specifically hypothyroidism and Cushing’s disease.  It's great to hear that your dogs haven't shown any obvious signs of these, although if your vet has any concerns then they may ask to test, particularly for Demodex which doesn't show many other signs.  Other possible causes can include scratching as a result of abdominal pain or skin disease.  However, i can tell from your description of the seasons that you may have read about cyclic or seasonal flank alopecia.  The prognosis for this is good i.e. dogs tend to retain their health despite the skin changes and it can self-resolve between  repeats of the season.  The improvements may appear less over successive years.  The change is thought to be connected to daylength exposure, but little is currently known about it.  It's certaintly worth ruling more serious problems out and your vet may have suggestions that may help to reduce the symptom.

I'm taking the heeler in Tuesday and I'll ask my vet about my hanging tree cow dog if I need to bring him in. The other dog is already having his fur grow back in. Iv talked to other people who have this breed and there dogs are having the same issue with there dogs fur fading on the flanks during winter coat blow out. I am giving them melatonin as of right now.