Multiple things can cause increased salivation, or drooling. Drooling can be normal or a sign of significant problem.
Some cats drool when they are very relaxed and purring. They may even knead their front paws back and forth like kittens do when nursing on their mother.
Sometimes anxious or fearful cats will drool. We sometimes see this during examination of otherwise healthy cats. Cats that are nauseated may drool. Motion sickness can cause nausea and drooling during car rides.
Cats can become nauseated from illness as well. Pancreatitis, constipation, diarrhea, intestinal infections and gastrointestinal foreign objects can all cause nausea and drooling.
Some respiratory infections such as calicivirus and herpes virus can cause severe tongue ulcers, pain and drooling. Foreign objects stuck in the mouth such as chicken bones, sewing needles, or plant awns cause pain and drooling. Bee or wasp stings as well as the bitter taste and toxins of certain frogs and toads trigger drooling. Certain plants have oxalate crystals in their leaves, which causes irritation and swelling of the mouth when eaten or nibbled. We often notice a bad odor to the mouth in these cats.
Cats with significant dental disease such as an abscessed tooth, periodontal disease, a fractured tooth, or pain from cavity lesions or tongue ulcers.
One of the saddest causes of drooling in cats is cancer. Cats will sometimes develop cancers such as squamous cell carcinoma, fibrosarcoma, or lymphoma in their mouth, especially under the tongue. The cat cannot swallow or chew as effectively as usual as the tumor increases in size, and so they then start to drool.
So what should you do if your cat drools? Call you veterinarian and schedule an examination immediately. Some cats may need sedation if their mouth is painful. Dental issues, foreign objects, cancers and many infections will only get worse and potentially impossible to treat with time so intervening early is critical. I have personally seen drooling in cats from all of these causes. Early intervention is always best. Dr Tammy Sadek