When it comes to calming "nuisance-barking" dogs, a spritz of fragrance under the chin is more effective than electric shock, a test by the Animal Behavior Clinic at Cornell's College of Veterinary Medicine has found.

Dog owners who tried both types of anti-barking collars preferred citronella spray over shock for their pets, according to a report in the Journal of the American Animal Hospital Association (May-June 1996, Vol. 32).

"Either type of collar can be a supplement or an alternative to behavior modification. The dog owners who tested these collars for our study felt the citronella spray was more effective and more humane than electric shock," said Soraya V. Juarbe-Díaz, D.V.M., a resident in the Cornell Animal Behavior Clinic who ran the study with volunteer dog owners.

Nuisance-barking dogs sound off for no particular reason. "Many dogs bark when they hear other dogs barking," said Katherine A. Houpt, V.M.D., director of the Animal Behavior Clinic. "And there are certainly times when we want a dog to bark to alert us of something we should know about. But nuisance barkers may bark just because they are highly territorial or because barking is a learned, attention-seeking behavior."

Nuisance, inappropriate or excessive barking make up between 13 and 35 percent of behavior-problem complaints by dog owners, Houpt noted. "Nuisance barking may be manageable with behavior modification, but some owners are unwilling or unable to provide consistent, appropriate corrections," she said. "Or the barking may occur when the owners are not around, so they can't deliver corrections when the misbehavior occurs."

So the animal-behavior experts recruited dog owners from the Ithaca area through newspaper articles and radio news stories about their research. They selected nine dogs that exhibited true nuisance barking and provided electric shock and citronella spray collars for two-week trials of each type.

The electric collars deliver an irritating shock of adjustable intensity when a vibration sensor in the collar detects barking. The citronella collar releases a spray of the plant-based fragrance when a microphone in the collar senses barking. The citronella collars were first marketed in the United States in 1995, although they have been available for years in most European countries, where shock collars are illegal for use on pets. Dogs in the collar test included a Shetland sheep dog, beagle, bull mastiff, two shepherd mixes, a cocker spaniel, West Highland white terrier, Labrador retriever and a Doberman pinscher.

For the eight dogs that wore both types of collars (one shepherd mix did not complete the study), all owners found the citronella collar to be effective in reducing or stopping nuisance barking and most preferred the fragrance spray. (The owner of the Doberman pinscher said both types worked, but preferred to use the electric shock collar.) Four out of eight owners said electric shocks had no effect on their dogs -- they kept on barking.

"Given the dog's sense of smell, it could be that a strange odor may be less tolerated than a presumably painful stimulus," the veterinarians speculated in the journal article. Once dogs learn that barking results in a fragrance spray, a placebo or "dummy" collar may be substituted in some cases and work just as well, they added.

The citronella collars were not without problems, Juarbe-Díaz noted. Unless the microphone's sensitivity is properly adjusted, it picks up sounds of other dogs barking, "and that's not fair to your pet. Punishment for misbehavior must not occur at random; the dog needs to know why it's being punished," she said.

And one dog owner complained that citronella oil stained the upholstery when the couch-potato pooch barked. But no one complained of the oil's smell, Juarbe-Díaz said.

"One owner thought the scent was preferable to her dog's body odor."