Excessive drooling in cats is a symptom of contentment, anxiety, teeth or gum disorders, broken teeth, cranial nerve damage, kidney complications, infected or damaged salivary glands, rabies or the feline herpes virus. Drooling also results from certain medications, plants and alcohol-based flea repellents.
The most common reason for excessive drooling is to express contentment. When accompanied by kneading of the paws, this instinct reflects the cat's behavior during infancy when it would knead around its mother's nipple to stimulate lactation during feeding. Heavy drooling can also signify an anxious response towards bitter medication or a trip to the vet. Liver complications also cause excessive salivation, but this symptom is typical of cats that are still growing.
A cat may have contracted the feline herpes virus if a fever, sneezing, eye discharges or loss of appetite accompany the salivation. Excessive drooling is also a symptom of rabies if it occurs alongside a fever, seizures, paralysis, a dropped jaw, trouble swallowing, lack of coordination, unusual shyness or aggression, excessive excitability, constant irritability or drastic changes in attitude and behavior. Consult a veterinarian immediately if a cat appears to have contracted rabies or the feline herpes virus or is suffering from liver complications.