Q: My cat Myrtle sometimes drools. Should I be concerned?
A: It depends. Many cats drool while purring. I can't tell you the number of times I've stood up, after one of my cats lay purring on my lap while I pet her, to find my slacks soaked with cat saliva. Conversely, some cats drool when they're stressed.
Drooling often results from chewing houseplants, especially those that contain insoluble oxalate crystals. These needle-sharp crystals become embedded in the cat's lips, tongue and sensitive tissues lining the mouth and throat, causing burning pain.
Plants that contain insoluble oxalate crystals include Anthurium, Caladium (elephant ear), calla lily, Dieffenbachia (dumb cane), peace lily, Philodendron and Schefflera.
Treatment starts with removing the plant material and encouraging the cat to drink cool water. A cat that refuses to drink may be enticed by adding some liquid from a can of tuna. A little milk or yogurt may help, too, because its calcium binds the oxalate crystals.
Sometimes, drooling indicates a medical problem.
A common one is oral disease, such as gingivitis, an abscessed tooth or a cancerous mass on the gums or beneath the tongue. A "foreign body," such as a sliver of wood, may even be stuck in the mouth.
Another cause of excessive drooling is gastrointestinal disease. Nausea, abdominal pain, liver disease and kidney failure are common sources of stomach upset and drooling.
Other times, a neurologic disorder is responsible. Cats with paralysis of the nerves that control the swallowing muscles drool, as do those that feel dizzy from vestibular disease.
Some drugs, including veterinary and human medications as well as illicit drugs, induce drooling in cats. I wondered why some cats drooled after I gave them a particular oral liquid antibiotic. I learned the answer early in my career when I dosed a cat and she immediately spat the medicine back at my open mouth: It's horribly bitter.
Finally, certain chemicals cause drooling, including some insecticides and household cleaners.
If Myrtle's drooling isn't associated with purring or chewing houseplants, have your veterinarian evaluate her.
Editor’s Note: Excessive drooling and avoidance for eating may be signs of dental disease in cats.
Lee Pickett, V.M.D. practices companion animal medicine in North Carolina. Contact her at email@example.com.