As you probably already know it is highly unlikely a deer or elk would attack, but in the one in a million chance one would (has happened I know). Then Bear spray or mace which is an irritant would just as likely cause them discomfort and to disengage an attack as it would a bear or person that was attacking. Nother words I don't think they'd like it.
Did Trigger attack and you had to use your bear spray? Sorry, I couldn't resist. I would think it would work on deer or elk but who really knows. As mentioned before, it is an irritant and should effect any animal.
I work with horses for a living and it will and does effect horses . It will not necessarily effect their skin but if sprayed in their face wear it is hitting more sensitive like the membranes around the eyes mouth or nostrils it would work. A few years ago in yellowstone a ranger was attacked by a cow elk around Mommouth springs . She had a calf with her and she charged him and knocked him off his bike. He turned his bear defense on it and it turned the cow away .
I am always amazed at the amount of scent control products that exist on the market today. But they are there for a reason. Game animals have incredible noses and if you go out into the field smelling like body odor, summer sausage, gasoline and last night's Miller High Life fiasco you will probably not be punching a tag. Scent control sprays aren't cheap though. On a college student budget I had a serious need to alleviate at least some of my hunting costs. This is why I decided to...