They don't last long where I live but they sure are a nuisance for the month or so that they are there, which is right now! I live in Quebec Canada and my dog has gotten them on his paws a couple of times and he hates it and i have the hardest time trying to get them out of his coat. Now I recognize them and we stay clear of them. Only on the odd occasion do we get caught. I agree with other members boots don't work my dog was like a statue as well would not walk with them in the Winter he was like a crippled dog:) Try to avoid them or take a different route
I would try another walking route maybe a close by park ,a park trail, or even a high foot ball field or track.I know some dogs do not like those boots one of my dog got a infection on their paws we had to put some boots on them when we put them on she stood their like a statute and would not move.So I would try a new route first.
If you do decide to get boots make sure to get them from a good company. The cheap boots do not stay on the feet. When you put them on your dog will probably high step for a while, and then (hopefully) settle down.
We have some sticky thorny balls here too. But they might not be the same thing. Ours are called BURDOCK and when they put their seeds out they are a darned nuisance. I got them all caught up in my hair yesterday. I usually keep away from Burdock when it is seeding for that reason, but was distracted yesterday while looking for walnuts.
Burdock is a plant that grows about 2-3 feet high, is pretty obvious (so if identified, can be kept away from) I tried to dowload a picture of Burdock to show you, just now but it didn't download properly. Put it in the search engine and take a look, and see if it is that plant.
The only help I can offer is once you know exactly how to identify the plant, you will get used to seeing it in certain places where you take Luigi for walks. The only thing to do is keep away from those areas if you can. Boots are an option I suppose. It depends how you think he will get on with wearing them. I know my dog wouldn't tolerate them.