Thanks to the Web, information and misinformation is spreading faster than ever before. Anyone with an internet connection and an email address is susceptible to a daily bombardment of news flashes, hoaxes, gossip, rumors, and urban legends, and it’s often difficult to discern what’s believable and what should be immediately dumped into your inbox’s “Trash.”

Information about dogs, both dubious and credible, is circulating around the internet along with stories about gas boycotts, terrorist threats, and get-rich-quick schemes. We’ve tracked down and dissected some of the most common “rumors” about products which may endanger your dog’s health, and gone straight to the source to bring you the truth.

The Rumor: Febreeze Fabric Spray is Harmful to Dogs

Perhaps the original internet rumor regarding a threat to pets’ health involved Febreeze Fabric Spray. The fabric refresher spray was introduced in the late 1990’s; in December, 1998, it became the subject of alarming emails forwarded to thousands of people. The original email, from an unknown source, claimed that “multiple” dogs and cats had become ill, some fatally, after their owners used Febreeze in their homes or directly on the pets’ bedding or living area. The email blamed the deaths on two components of the spray: zinc chloride and aerosol propellants.

In fact, Febreeze contains neither zinc chloride nor aerosol propellants (it’s a pump, not a spray). Like most cleaning products, it was extensively tested for safety concerns before its release to the public. A consensus of veterinarians, scientists, and toxicologists have concluded that Febreeze, when used as directed, is safe to use around dogs and cats. (See a statement from the manufacturer here.)

Rumor: Swiffer Wet Jet is Harmful to Dogs

As the Febreeze scare died down, another rumor regarding cleaning products sprang up to take its place. In 2004, a widely circulated email stated that a German Shepherd Dog and two cats died of liver failure after their owner cleaned his floor with the Swiffer Wet Jet. The email further claimed that the owner’s investigation into his pets’ deaths revealed that the Wet Jet cleanser contained antifreeze, which was ingested by the pets after they crossed the wet floor and then licked their paws.

In fact, the Wet Jet cleanser does not contain ingredients that are harmful to pets. According to the manufacturer, Proctor and Gamble, the cleanser is composed mostly of water, with a 1-4 % addition of propylene glycol n-propyl ether and isopropyl alcohol. The dangerous compound in antifreeze is ethylene glycol; proplyene glycol is categorized as “generally recognized as safe” by the FDA. Further, the Wet Jet manufacturers state that it is specially formulated to dry without leaving a residue, making it a good choice for pet owners. (You can read their statement here.)

Of course, dog owners should decide for themselves which cleaning products they are comfortable using in their homes, and use all products with care around their dogs. It goes without saying that all cleaning products should be kept out of reach of curious canines.

Rumor: Cocoa Bean Mulch is Harmful to Dogs

In 2003, a rumor began circulating that “many” dogs had died after ingesting mulch made of cocoa beans. Although there is no official record of fatalities, the main message of this rumor is true.

Cocoa mulch is a rich, fragrant mulch made from the waste shell from the extraction of chocolate from cocoa beans. It smells sweet, like chocolate, and therefore can be appetizing to dogs. Unfortunately, also like chocolate, it contains caffeine and theobromine, both of which can be hazardous and even deadly for dogs.

Different types of chocolate contain varying amounts of theobromine; white chocolate has the least per ounce, while unsweetened baking chocolate has the most. Cocoa mulch can contain as much or more theobromine per ounce than baking chocolate, making it a highly dangerous “treat” for curious dogs. Depending upon the amount ingested, theobromine can cause symptoms ranging from gastrointestinal upset to rapid heartbeat, seizures, and death.

An official statement from Hershey’s confirms that 50% of dogs who ingest cocoa mulch can suffer harm; however, it goes on to state that “98% of dogs won’t eat it.” It would seem prudent, however, not to leave it up to chance, and to use a less sweet-smelling mulch in areas of your gardens that are accessible to dogs.

Rumor: Grapes are Harmful for Dogs

In 2004, another “Warning to Dog Owners” began circulating. This one claimed that grapes and raisins can cause renal failure in canines.

The story was quickly picked up by a number of veterinary and general-interest news sites—and as it turns out, it, too, is true. Dogs can become fatally ill after ingesting grapes and raisins. In some dogs, as few as seven raisins brought on symptoms, including vomiting, diarrhea, and shaking. The fruits can cause the kidneys to shut down, and often, even aggressive treatment is unsuccessful.

No one is sure why grapes and raisins cause this reaction in dogs. All dog owners should refrain from feeding grapes and raisins as treats to their dogs, and keep them well out of reach. If you suspect your dog has ingested grapes, or if he starts showing symptoms, contact your vet immediately.

No doubt the coming months will see a new crop of mass email warnings and rumors about products, food stuffs, and practices that are harmful for dogs. If you hear something “through the grapevine” that causes concern, we suggest going straight to the source. If it’s a man-made product that’s rumored to cause harm, contact the manufacturer with your questions. For natural products, contact your veterinarian or a pet poison control center. And, of course, use prevention—such as keeping questionable products away from your dogs—as a cure, and common sense as a guide.