No, Toby's fur didn't interfere and the collar didn't cause any irritation. Its not very wide or thinck and reminded me of those cheap flea collars that never worked that we used to buy back in the day.
For bad anxiety the collar may not be enough, but it all depends on the dog. My personal experience was that it didn't do a whole lot and wasn't worth the money.
For Toby it just took the edge off of his anxiety. I used it for a few months then switched to a Thundershirt, which helped a lot more. I tried the DAP collar and Thundershirt but it didn't give him any more relief than the Thundershirt alone.
There are a variety of natural anti-anxiety medications you might like to try that I found more effective than the DAP collar, like Zylkene/Lactium, Rescue Remedy and other holistic anti-anxiety medications. For Toby they all worked better than the DAP collar and were less expensive over the long term.
For us, after 9 months of positive training and numerous methods of treating anxiety naturally, I eventually medicated Toby. My only regret was not doing it sooner, he's still nervous but over all MUCH happier. I finally feel like his anxiety is manageable and that he's living a happy life instead of feeling tortured all the time. It's been almost two years and I've weaned Toby onto a lower dose, but its likely he will need medication for the rest of his life.
Anxiety and depression have to do with chemical imbalances of the brain. Some individuals need medication to lead a normal life, similarly to how some individuals need to take insulin for diabetes.
I am very leery to use it but if it improves her quality of life I will try it.If you don't mind my asking, what med is your Toby taking. PM if you like.