Yes, it would work on a cougar, but first you have to see the cougar and have enough time to deploy the spray. Which you probably won't since the cougar's main method of hunting is stealth. I'd bet you have, if you hiked any miles at all, walked right under a curious cougar or ten.... Far more of them have seen/smelled you than you will ever know are there.
A friend of mine, a Lakota indian who grew up in the Black Hills, once said to me... if a cougar were to stalk and attack someone, they would never know it.
Our long-time Sponsor, BackcountryGear.com - The leading source for ultralite/lightweight outdoor gear:
Affiliate Disclaimer: This forum is an affiliate of BackcountryGear.com, Amazon.com, R.E.I. and others. The product links herein are linked to their sites. If you follow these links to make a purchase, we may get a small commission. This is our only source of support for these forums. Thanks.!