Dogs sense bad days
I have never had a dog trained to help with Matt seizures mostly because we have already had a dog and to get one for Matt all the placement places say no other dogs.
I believe however dogs just have a sense that something is happening and will try to tell you in some way or another. The other day while Matt was having his roller coaster day our dog Fenris would not stop bothering me, I couldn't figure out what he wanted. He had already had his walk, food, fresh water and treat so he was good, however he just wanted to tell me something. Now Fenris is a really good dog and only comes to me for a reason if I am busy doing something he is usually doing his own thing and leaves me alone.
However this day he was all over me even trying to crawl on me while I was working on the computer or crawl on my clean clothes I was folding, he did not want to leave me alone at all. It wasn't till the next day I realized that every time he was coming to bug we was just before Matt was having his low moments. My other dog Kara used to do the same thing crawl on my lap to tell me to watch Matt. I am not always aware to watch the signs of my dog when it comes to Matt but I am going to pay more attention now.