My senior dog is drooling a lot. What does it mean and is it serious?

Too much drool, or hypersalivation, can be a sign of illness.

Here are some causes:

Heat stroke and heat exhaustion, nausea and anxiety can cause episodes of drooling.

Mouth disease and tooth decay: Tarter buildup can rub against the inside of your dog’s lip, causing drool. To check, pull his lip back toward his ear. Do his teeth look like concrete? Are they brown? Are his gums red, swollen, or bleeding? If so, try a professional cleaning and then daily brushing. Your vet can check for gingivitis, mouth ulcers, and tumors as well.

Organ disease: Liver and kidney diseases, for example, can cause drooling. As they age, dogs are more likely to get sick. Vets suggest annual checkups to diagnose and treat diseases early.

Poisonous plants: Common plants like tulips, azaleas, and chrysanthemums can not only make your dog drool, but also make him sick. Keep your dog from eating them. For a list of poisonous plants, consult the American Society for the Prevention of Cruelty to Animals (ASPCA).

Stomachaches: Dogs don’t tend to think before eating. Vets report pulling some strange items from their stomachs, from tennis balls to socket wrenches. This can cause nausea, discomfort and pain. Keep dangerous items away from him.

Upper respiratory infections: Drooling can signal an infection of the nose, throat, or sinuses. Dogs that live in homes or shelters with other pets have a higher risk. Stress is also a factor. Only your vet can properly treat an infection. But you can take steps to protect your dog: Keep him indoors, away from other pets, and wash your hands between handling different animals.

You’re the best judge of your dog’s behavior. If he’s acting strange for more than a day, he seems stressed, or he is not eating and playing as usual, it’s wise to see a vet.