The couple, which met on the set of the hit supernatural U.S. Tv show, took Dobrev's beloved ginger cat Moke to the vet after it was struck down with a mystery illness.
Dobrev later took to her Twitter.com page to share the drama with fans and post a series of snaps, including one of a concerned-looking Somerhalder holding the cat, which is wearing a plastic cone collar.
She writes, "Driving sleepy to work... Barely got any zzzz's (sleep) due to scary trip to kitty hospital in the middle of the night... Little guy... Ugh, scary stuff. That's one way to get your heart rate up... Kid is doing much better now. Passed out on the good stuff, wrapped in mommas (sic) jacket."