If its not one thing its another. 
This morning Chance started itching his neck around his collar a lot.
We took his collar off and noticed there was an isolated rash.
We haven't changed his diet. The only new thing we gave him was Chicken broth in his food but that is organic and he has had it in the past w/out this happening.
He is on a medication for his infected paw but I would of assumed the rash would be all over his body and not in one isolated spot on his neck. I did not see a bite mark on his neck or a scratch where the rash could of originated.
I don't know if I should just wait it out and see if the rash spreads or take him back into the vet for another exam. Seriously…he has already been to the vet this week and it is quite costly!
If you think it might be a contact reaction to something that he got on or under his collar, my suggestion would be some benadryl for the itching and put his collar in the wash.
The dose is 1mg per 1 kg of body weight. So usually 1, 12.5 mg tablet is just right.
I will have alex take some pictures tonight and post them on the forum
So you can see our "Lil' Red Neck Chance"
Keeps itching it. I think its possible it's Kiya bites healing…but I can't tell.
He is still itching. We are pretty sure these are little scabs from Kiya biting during play.
don't rule out mites either. need a scrape at the vet to deterimine what kind. or flea bites and an allergic reaction. might have picked up a stray flea or two outside - if you have bunnies around in your yard they carry them.
Chance started itching again, every morning around his collar area. It is getting worse as he keeps itching the area non stop now. We thought it might be his chicken evo food that he has been eating for years, so we switched him to red meat evo.
So far he is still itching this morning.
I know sometimes dog food companys "add" something new to the product.
Maybe he should try a different food?
Has anything else new happened? New clothes soap, new dryer sheets?
Any new plants added to the yard that might cause some issue with him?
Everything has been pretty stable. Switching foods is always a pain, Chance has very sensitive stomach.
Why not use one of those wide/thick collars to cover up the irritated area, so when he tries to scratch at it he can't. Leave it one for a week or something to let the wound "rest" for awhile. Pretty sure that's all it needs.
Otis has been scratching his neck too lately and I just noticed last night that he seems to be blowing his coat ..again..mainly the white fur, more so then the brindle, is that common.?
Could Chance be getting dry and itchy due to winter, I know you are in Cali, but maybe the weather gets drier in the winter, more heat on in the house or something?
I'm kind of coming in late on this, but I don't recall anyone asking what kind of collar it is you use on Chance or whether he gets itchy only when he wears it. I had a cat once who was allergic to nylon collars. They drove her nuts. I played the devil finding a natural leather cat collar for her with the stretchy escape loop, but once it was on her, she stopped itching altogether.
I know normally one wouldn't want to put a collar on a cat, but I lived off base in Germany at the time and wanted her to be able to get home if she ever got out. It worked, too.
When Ruby got a few fleas this fall, I bathed her with Virbac Epi-Soothe and I used an all natural Oatmeal/Tea Tree Oil spray to soothe her skin after the fleas were killed. It really helped stop her itching.
Granted that won't fix anything regarding the allergy, but it might give Chance some temporary relief from the itching (the spray especially - I used it 3x per day) while you figure out what he is allergic to.
Good point about the collar. We are going to wash and are keeping it off for now.
We have switched the food and take his collar off when he is at home. He seems to be doing a bit better but still itching his neck.