Porky and Sylvester are driving to Albuquerque, New Mexico (home of Bugs Bunny's famous "left turn" and also their destination in Jumpin' Jupiter (1955)) when Porky decides to stop for the night at the hotel in Dry Gulch; actually a ghost town, a fact which sends Sylvester to trembling, but which Porky seems oblivious to. As in "Scaredy Cat," Sylvester alone is alert to the danger from murderous mice that have taken up residence in the hotel. Unlike the previous cartoon, however, the mice are (mostly) unseen, except for tiny, malevolent pairs of eyes in dark corners (and the moose heads over the main desk and Porky's bed). No matter; Porky declares it to be "a perfectly splendid place to spend the night" and checks in.
The mice, meanwhile, do everything they can to kill and/or scare Porky and Sylvester. (In one scene, the mice are seen in silhouette beneath a sheet, standing on each other's shoulders as they appear to the frightened cat to be a ghost.) As always, Porky does not see the danger until Sylvester has chased the mice away, leaving him holding the bag—or, in one case, the noose the mice have dropped around Porky's neck, out of the way of which the cat has just pushed Porky out of the way of. Porky demands to know why Sylvester shoved him, leading to one of the film's funnier sequences as Sylvester pantomimes the moose head and the noose dropping from it. Porky then declares the cat to be a "c-cow-eh-c-cow-eh- you great yellow cat, you!" (later asking, "is th-there any, uh, in-eh-insanity in your family?") and Sylvester soldiers on all night, guarding his master with a shotgun he earlier wrestled away from the mice.
Dawn finally breaks, ridding the ghosts out of the hotel, ending the bleary-eyed cat's vigil as Porky awakes: "Eh, this r-really is a r-restful place. I think we should stay here a w-week to t-ten days and get really rested up!" This is the last straw for Sylvester, who (off-screen) clubs Porky over the head with the shotgun butt while he is freshening up and singing "Home on the Range," leaving him stuck on the first verse like a needle skipping on a record ("Oh, give me a home, where the buffalo roam and the deer and the antelope (WHAM!!), and the deer and the antelope, and the deer and the antelope pl-pl, and the deer and the antelope pl-pl, and the deer..."). Sylvester, meanwhile loads the car with the luggage and Porky and speeds away from the hotel. After a last look back, Sylvester breathes a sigh of relief—not seeing the pairs of eyes blinking from the speedometer as the film closes.
Some cartoon buffs view Claws for Alarm as the creepiest and darkest of the trio of cartoons centered on Porky and Sylvester's weird vacations, noting the simpler drawings and the almost never-seen mice. Emru Townsend, writing for the online animation magazine Frames Per Second, lists Claws as one of his favorites for Halloween, and comments: "Claws for Alarm makes the cut for Halloween because, unlike in the other two cartoons, the sense of fear and dread comes in from the very first frame." Townsend also cites the "true horror-movie fashion" of the ending, where the "monsters" are not completely vanquished.
At about 4 minutes into the cartoon, a mouse resembling a miniature Wile E. Coyote (a Chuck Jones creation) can be seen with a knife, about to swing down at Porky.
Much like Scaredy Cat and (to a lesser extent) Jumpin' Jupiter, Claws for Alarm has been shown edited on television :
On CBS and ABC, the scene where Sylvester plugs a gun with his finger and the gun fires, causing the bullet to go through his finger and out via his tail (to Porky commenting "Mice") was cut.
On Cartoon Network's pre-2002 airings (CN now airs this cartoon uncut), ABC, Nickelodeon and the syndicated "Merrie Melodies Show", the following parts were cut:
The scene where Sylvester uses a noose to demonstrate to Porky what could have happened to him had Sylvester not saved him was cut on ABC, "The Merrie Melodies Show" and Cartoon Network before 2002, but was left uncut on Nickelodeon (and later on post-2002 CN). This scene was also cut on Cartoon Network (pre-2002) whenever Daffy Duck's Quackbusters aired.
The scene where a noose lowers on Porky while Porky is sleeping, Sylvester cuts the noose with a razor and Porky accuses Sylvester of attempted murder was cut on ABC, "The Merrie Melodies Show", pre-2002 Cartoon Network, and Nickelodeon.
The scene where a moosehead has a rifle emerging from its mouth to try and kill Porky and Sylvester beating it up was cut on pre-2002 Cartoon Network and Nickelodeon.