Sabre teeth are actually a North American ice age mammalian evolution where the canine teeth were curved and elongated. I think all sabre tooth genes are extinct by now, though.

How does this affect jackrabbits? Probably doesn't, American tigers had sabre teeth. No more tigers in North America anyway. Sabre tooth tigers are long gone.

I figure those cats were extracting water from ice then and there. When the ice age ended, there was no need to scrape ice with the canines.

I believe we have an ice age now at UConn and I actually have been scraping ice with my canine teeth, which is ridiculous but true.

I'm no scientist but freezing your teeth would naturally expand them and melting ice with your canines would curve them and elongate them as ice water drips.

Furthermore, a sabre is a type of sword with no edge that was used to clear paths through the jungle.

What's more, sabre teeth can be used to warm up the air above your feet. You just have to point your canine teeth at the floor, and breathe out hot air if it's freezing cold where you're walking.

Leaving them constantly extended from the jaw will work as a form of evaporative heating.

Your mouth will automatically heat your sabre teeth, which will thereby heat the air in front of your face, actually probably by melting floating ice-water particles in a frozen room/house/shelter, frozen cave or igloo.

Long story short, to use sabre teeth like a large cat, hydroplane on ice with your canine teeth to hunt for green wild grass.